Authors/Thomas Aquinas/posteriorum/L2

Lecture 1 Whether the definition which signifies the quod quid of a thing can be demonstrated

Latin	English
	BOOK II Lecture 1 (89b21-90a35) EACH OF THE FOUR QUESTIONS WHICH PERTAIN TO SCIENCE IS ONE WAY OR ANOTHER A QUESTION OF THE MIDDLE
lib. 2 l. 1 n. 1 Postquam philosophus in primo libro determinavit de syllogismo demonstrativo, in hoc libro intendit determinare de principiis eius. Est autem duplex principium demonstrativi syllogismi, scilicet medium eius et primae propositiones indemonstrabiles. Dividitur ergo liber iste in duas partes: in prima, determinat de cognitione medii in demonstrationibus; in secunda, de cognitione primarum propositionum; ibi: de principiis autem qualiter fiunt cognita et cetera. Quia enim in primo libro habitum est quod omnis doctrina et omnis disciplina fit ex praeexistenti cognitione; in demonstrationibus autem cognitio conclusionis acquiritur per aliquod medium et per primas propositiones indemonstrabiles; residuum erat investigare qualiter ista innotescant.	After determining about the demonstrative syllogism in the first book, the Philosopher intends in this [second] book to treat concerning its principles. But there are two principles of the demonstrative syllogism, namely, its middle and the first indemonstrable propositions. Therefore this book is divided into two parts. In the first he determines concerning the knowledge of the middle in demonstrations. In the second concerning the knowledge of the first propositions (99b18) [L. 20]. For since it has been established in the first book that every doctrine and every discipline takes its start from pre-existing knowledge, and since in demonstrations the knowledge of the conclusion is acquired through some middle and through the first indemonstrable propositions, we are left with the task of investigating how these come to be known.
Prima autem pars dividitur in duas partes: in prima, investigat quid sit medium in demonstrationibus; in secunda parte inquirit quomodo illud medium nobis innotescat; ibi: quomodo autem quod quid est ostenditur et cetera. Quia vero medium in demonstrationibus assumitur ad aliquid innotescendum de quo poterat esse dubitatio vel quaestio, ideo circa primum duo facit: primo enim, ponit numerum quaestionum; secundo, ex ipsis quaestionibus investigat propositum, ostendens qualiter quaestiones pertineant ad medium demonstrationum; ibi: quaerimus autem cum quaeramus et cetera. Circa primum tria facit: primo, enumerat quaestiones; secundo, manifestat compositas quaestiones; ibi: cum quidem enim utrum hoc etc.; tertio, simplices; ibi: quaedam autem alio modo et cetera.	But the first part is divided into two parts. In the first he inquires what is a middle in demonstrations. In the second part he inquires how that middle is made known to us (90a36) [L. 2]. But because the middle in demonstrations is employed in order to make known something about which there might have been doubt or question, therefore in regard to the first he does two things. First, he lays down the number of questions. Secondly, from these questions he pursues his investigation by showing how the questions pertain to the middle of demonstrations (89b38). Regarding the first he does three things. First, he enumerates the questions. Secondly, he explains complex questions (89b26). Thirdly, simple questions (89b32).
lib. 2 l. 1 n. 2 Dicit ergo primo quod aequalis est numerus quaestionum et eorum quae sciuntur. Cuius ratio est, quia scientia est cognitio per demonstrationem acquisita. Eorum autem oportet per demonstrationem cognitionem acquirere, quae ante fuerint ignota: et de his quaestiones facimus, quae ignoramus. Unde sequitur quod ea quae quaeruntur sint aequalia numero his quae sciuntur. Quatuor autem sunt quae quaeruntur, scilicet quia, propter quid, si est et quid est: ad quae quatuor reduci potest quidquid est quaeribile vel scibile.	He says therefore first (89b21) that the number of questions is equal to the number of things that are scientifically known. The reason for this is that science is knowledge acquired through demonstration. But things which we previously did not know are those of which we must seek knowledge by demonstration: for it is in regard to things which we do not know that we form questions. Hence it follows that the things we inquire about are equal in number to the things we know through science. But there are four things that we ask, namely, quia [i.e., is it a fact that], propter quid [i.e., why, or what is the cause or reason], si est [if it is, i.e., whether it is], quid est [what is it]. To these four can be reduced whatever is scientifically inquirable or knowable.
Dividit autem in I topicorum quaestiones sive problemata aliter in quatuor, quae omnia comprehenduntur sub una harum quaestionum, quae dicitur quaestio quia. Non enim ibi intendit nisi de quaestionibus ad quas dialectice disputatur.	However in Topics I he divides questions or problems into four kinds in a different way, but all of them are included under one of the questions listed here, namely, the one called quia. For in the Topics he is concerned only with questions to be disputed dialectically.
lib. 2 l. 1 n. 3 Deinde cum dicit: cum quidem enim utrum hoc etc., manifestat propositas quaestiones, et primo compositas. Ad cuius evidentiam considerandum est quod, cum scientia non sit nisi veri, verum autem significetur solum per enunciationem, oportet solam enunciationem esse scibilem, et per consequens quaeribilem. Sicut autem in II perihermeneias dicitur, enunciatio dupliciter formatur. Uno quidem modo, ex nomine et verbo absque aliquo apposito, ut cum dicitur homo est; alio modo, quando aliquid tertium adiacet, ut cum dicitur homo est albus.	Then (89b26) he clarifies the questions he laid down; and first of all the complex ones. To understand this it should be noted that science bears only on the true, and the true is not signified except by an enunciation; therefore, only the enunciation can be scientifically knowable and so inquirable. But, as it is stated in On Interpretation II, the enunciation is formed in two ways: in one way from a name and a verb without an appositive, as when it is stated that man is; in another way when some third item is set adjacent, as when it is stated that man is white.
Potest igitur quaestio formata referri, vel ad primum modum enunciationis, et sic erit quasi quaestio simplex; vel ad secundum modum, et sic erit quaestio quasi composita, vel in numerum ponens, quia videlicet quaeritur de compositione duorum.	Therefore the questions we form can be reduced either to the first type of enunciation so that we get, as it were, a simple question; or to the second type, and then the question will be, as it were, complex or put in number, because, namely, the question concerns the putting together of two items.
Circa hunc ergo modum enunciationis duplex quaestio formari potest. Una quidem, an hoc sit verum quod dicitur. Et hanc quaestionem primo exponit, dicens quod cum de aliqua re quaerimus utrum illa res sit hoc aut illud, et sic quodammodo ponimus in numerum (accipiendo scilicet duo, quorum unum est praedicatum et aliud subiectum; puta cum quaerimus utrum sol sit deficiens per eclipsim vel non, et utrum homo sit animal vel non), tunc dicimur quaerere quia: non ita quod hoc quod dico quia sit nota vel signum interrogationis, sed quia ad hoc quaerimus ut sciamus quia ita est. Cuius signum est, quia cum invenerimus per demonstrationem, quiescimus a quaerendo; et si in principio hoc scivissemus, non quaereremus utrum ita sit. Inquisitio autem non cessat, nisi habito eo quod quaerebatur. Et ideo cum quaestio qua quaerimus utrum hoc sit hoc, cesset habito quod ita est, manifestum est quid huiusmodi quaestio quaerit.	According to this latter type a twofold question can be formed: one of them is whether this is true which is stated. This question he expounds first, saying that when we ask concerning some thing whether that thing is this or that, so that in effect we are somehow putting it in number, namely, by taking two things one of which is predicate and the other subject, as when we ask if the sun is failing because of an eclipse or not, and is man an animal or not, then we are said to ask quia: not in the sense that the word “quia” functions as a question mark, but because we are asking in order to find out quia [i.e., that] it is so. An indication of this is that when we have discovered it through demonstration, we cease our questioning; and if we had known it at the very beginning, we would not have asked whether it is so. But inquiry does not cease until that is obtained which was asked. And so, since the question in which we ask whether this is this ceases once we have certified that it is so, it is clear what a question of this kind asks.
lib. 2 l. 1 n. 4 Deinde cum dicit: cum autem scimus etc., manifestat consequentem quaestionem, quae etiam in numerum ponit; et dicit quod cum scimus quia ita est, quaerimus propter quid ita sit. Puta, cum scimus quia sol est deficiens per eclipsim, et quod terra est mota in terraemotu, quaerimus propter quid sol deficiat, aut propter quid terra moveatur. Hoc igitur sic quaerimus, ponentes scilicet in numerum.	Then (89b28) he clarifies the next question which also puts in number, ‘I saying that when we know that it is so, we ask propter quid [i.e., why] it is so. For example, when we know that the sun is failing through an eclipse and that the earth is moved during an earthquake, we ask why the sun is failing or why the earth is being moved. Therefore we ask it in this way, namely, by putting in number.
lib. 2 l. 1 n. 5 Deinde cum dicit: quaedam autem alio modo etc., manifestat alias duas quaestiones, quae non ponunt in numerum, sed sunt simplices. Et dicit quod quaedam quaerimus alio modo a praedictis quaestionibus, scilicet non ponentes in numerum; utpote si quaeramus an sit Centaurus vel non: hic enim simpliciter quaeritur de Centauro an sit, non autem quaeritur an Centaurus sit hoc, puta album vel non. Et sicut scientes quia hoc est illud, quaerebamus propter quid, ita etiam scientes de aliquo quia est simpliciter, quaerimus quid sit illud, puta quid est Deus, aut quid est homo. Haec igitur et tot sunt illa quae quaerimus: quae cum invenerimus, dicimur scire.	Then (89b32) he clarifies the other two questions which do not put in number but are simple. And he says that we ask certain things in a manner different from the aforesaid questions, namely, by not putting in number; as when we ask whether or not there be centaurs, for in this case the question we ask concerning the centaur is simply whether it exists and not whether the centaur be this, say white, or not. And just as when we knew that this is this, we then asked why, so once we know of something simply that it is, we ask what it is, for example, what is God or what is man. These then and so many are the things we ask; and when we have found the answer, we are said to know scientifically.
lib. 2 l. 1 n. 6 Deinde cum dicit: quaerimus autem cum quaeramus etc., ostendit qualiter praedictae quaestiones se habeant ad medium. Et circa hoc tria facit: primo, proponit quod intendit; secundo, manifestat quod dixerat; ibi: dico autem quia etc.; tertio, probat propositum; ibi: contingit itaque in omnibus quaestionibus et cetera.	Then (89b38) he shows how the aforesaid questions are related to the middle. Concerning this he does three things. First, he states what he intends. Secondly, he explains what he had said (90a2). Thirdly, he proves his proposition (90a5).
Circa primum sciendum est quod praedictarum quatuor quaestionum, quarum duae ponunt in numerum et duae non ponunt, primam utrarumque in unam coordinat, scilicet quaestionem quia et quaestionem an est. Et dicit quod cum quaerimus quia hoc est hoc, aut cum quaerimus de aliquo simpliciter si est, nihil aliud quaerimus quam utrum aliquod medium ipsius quod quaerimus sit invenire vel non. Quod non dicitur secundum ipsam formam quaestionis. Non enim cum quaero an sol eclipsetur, vel an homo sit, ex ipsa forma quaestionis quaero an sit aliquod medium, quo possit demonstrari vel solem eclipsari, vel hominem esse: sed si sol eclipsatur, vel homo est, consequens est quod sit aliquod medium invenire ad demonstrandum ista quae quaeruntur. Non enim fit quaestio de immediatis, quae etsi vera sunt, non tamen habent medium; quia huiusmodi, cum sint manifesta, sub quaestione non cadunt. Sic ergo qui quaerit an hoc sit hoc, vel an hoc sit simpliciter, ex consequenti quaerit an sit huiusmodi medium. Quaeritur enim in quaestione si est, vel quia est, an sit id quod est medium; quia id quod est medium est ratio eius, de quo quaeritur an hoc sit hoc, vel an simpliciter, ut infra dicetur. Non tamen quaeritur sub ratione medii.	In regard to the first it should be noted that two of the aforesaid questions put in number and two do not. From the first member of each of these groups, he forms another grouping composed of the question that it is and the question if it is. And he says that when we ask that this is this, or when we simply ask concerning something, if it is, we are not asking anything else than whether or not a middle is to be found of that which we ask; and this is something not conveyed by the form of the question. For when I ask whether the sun is eclipsed or whether man exists, it is not obvious from the form of the question that I am asking whether there is some middle by which it might be demonstrated that the sun is eclipsed or that man exists; but if the sun is eclipsed or man does exist, the consequence is that some middle can be found to demonstrate the things which are inquired. For no one forms a question concerning immediate things which, although they are true, do not have a middle, since things of this sort, being evident, do not fall under a question. Thus, therefore, one who asks whether this is this or whether this absolutely is, as a consequence is asking whether there is a middle of this sort. For in the question if it is or that it is, one is asking whether that which is a middle exists, because that which is the middle is the reason of that concerning which one asks whether this is this or simply whether it is, as will be explained below. Nevertheless the question is not being asked under the aspect of middle.
Contingit autem, invento quod quaeritur per has duas quaestiones, cognoscere aut quia est aut si est: quorum alterum est cognoscere esse simpliciter, alterum esse in parte, sicut cum cognoscimus quod homo est albus; quia esse album non significat totaliter esse hominis, sed significat ipsum esse aliquid; et ideo cum homo fit albus, non dicitur generari simpliciter, sed generari secundum quid. Sed cum dicitur, homo est, significatur ipsum esse simpliciter; et cum homo fit ens, dicitur generari simpliciter.	Now it happens that having found the answer to what is asked by these two questions, one knows either that it is or if it is: one of which consists in knowing the existence absolutely; but the other in part, as when we know that man is white, because to be white does not signify the existence of man in his entirety but signifies him to be something. This is why when a man is becoming white, we do not say that he is coming to be absolutely, but in a qualified sense. But when it is asserted that man is, his existence is signified absolutely, so that when a man comes to be, he is said to become absolutely.
Cum ergo cognito quia est, quaerimus propter quid est, aut cognito si est, quaerimus quid est, tunc quaerimus quid sit medium. Et hoc similiter est accipiendum non secundum formam quaestionis, sed secundum concomitantiam. Non enim qui quaerit causam propter quam sol eclipsatur, quaerit ipsam ut medium demonstrans, sed quaerit id quod est medium: quia consequens est ut, hoc habito, possit demonstrare. Et eadem ratio est de quaestione quid est.	Therefore, when we know that it is and ask why it is, or when we know if it is and ask what it is, we are asking what is the middle. And as in the other cases, so here, this is gathered not from the form of the question but by way of concomitance. For one who seeks the cause why the sun is eclipsed is not seeking it as a middle which demonstrates, but he is seeking that which is a middle, because it is by way of consequence that once he has it, he can demonstrate. And the same applies to the question what is it.
lib. 2 l. 1 n. 7 Deinde cum dicit: dico autem quia aut si est etc., manifestat quod dixerat, quod quia est et si est differunt sicut in parte et simpliciter. Cum enim quaerimus utrum deficit luna aut utrum augetur, est quaestio in parte: in huiusmodi enim quaestione quaerimus si luna est aliquid; puta si deficiens, vel aucta, aut non. Sed cum quaerimus an luna sit, sive an nox sit, est quaestio de esse simpliciter.	Then (904) he manifests what he had said, namely, that that it is and if it is differ as in part and absolutely differ. For when we inquire whether the moon is waning or waxing, it is a question in part, since in a question of this type we are asking if the moon is something, namely, is it waning or has it waxed or not. But when we ask whether the moon exists or whether it is night, the question bears on existence absolutely.
lib. 2 l. 1 n. 8 Deinde cum dicit: contingit itaque in omnibus etc., probat propositum, scilicet quod praedictae quaestiones pertineant ad medium. Et primo, probat per rationem; secundo, probat per signum; ibi: quod autem sit medii et cetera.	Then (90a5) he proves his point, namely, that the aforesaid questions pertain to the middle. First, he proves it with a reason. Secondly, with a sign (90a24).
Concludit ergo primo ex praemissa manifestatione quod in omnibus praedictis quaestionibus, vel quaeritur an sit medium, scilicet in quaestione quia et in quaestione si est; vel quaeritur quid est medium, scilicet in quaestione propter quid et in quaestione quid est.	He concludes therefore first (90a5) from the explanation given above that in all the aforesaid questions one is either asking whether there is a middle, namely, in the question that it is and in the question if it is, or what the middle is, namely, in the question why and in the question what is it.
Et probat quod quaestio propter quid quaerat quid sit medium. Manifestum est enim quod causa est medium in demonstratione, quae facit scire; quia scire est causam rei cognoscere. Causa autem est quod quaeritur in omnibus praedictis quaestionibus. Quod primo manifestat in quaestione quia. Cum enim quaeritur utrum luna deficiat, quaeritur secundum modum supra expositum, utrum aliquid sit causa defectus lunae vel non. Et consequenter hoc manifestat in quaestione propter quid. Cum enim scimus quia est aliquid causa defectus lunae, quaeritur quid sit causa; et hoc est quaerere propter quid.	And he proves that the question why inquires what the middle is. For it is obvious that a cause is the middle in a demonstration which enables one to know scientifically, because to know scientifically is to know the cause of a thing. But it is precisely the cause that is being sought in all the above questions. That this is so he manifests first in regard to the question that. For when it is asked whether the moon is waning, then according to the manner explained above, what is being asked is whether or not something is the cause of this waning. Then he shows this for the question why. For once we know that something is the cause of the moon’s waning, we ask what the cause is; and this is to inquire why.
Et eadem ratio est in aliis duabus quaestionibus, ut per sequentia manifestat. Dicit enim quod, sive accipiamus aliquam rem esse non hoc aut hoc (puta cum dico homo est albus, aut grammaticus), sed accipiamus ipsam substantiam esse simpliciter; sive etiam non accipiamus rem aliquam esse simpliciter, sed rem aliquam esse aliquid, ponendo in numerum, (sive illud aliquid sit de numero eorum quae praedicantur per se, sive de numero eorum quae praedicantur per accidens), sive hoc modo sive illo accipiamus rem esse, causa eius est medium ad demonstrandum ipsam.	The same applies to the other two questions, as he shows in the following way. For he says that whether we assert not that something is this or that (for example, when I say that man is white or is a grammarian), but that the substance itself exists absolutely; or do not assert that some thing exists absolutely, but that some thing is something by putting in number (whether that something be a thing predicated per se or a thing predicated per accidens); no matter in which of these ways we take the thing to be, its cause is the middle for demonstrating it.
Exponit autem consequenter quod dixit, simpliciter substantiam esse, cum quaerimus de luna, aut de terra, aut de triangulo, aut de quolibet subiecto an sit, et ad hoc demonstrandum accipitur aliquod medium. Dico autem rem esse aliquid, cum quaerimus eclipsim de luna, aut aequalitatem, aut inaequalitatem de triangulo, aut de terra utrum sit in medio mundi vel non. Et ostendit quod non differt quantum ad propositum utrolibet modo accipiatur rem esse; quia in omnibus praedictis idem est quid est et propter quid.	Then he explains what he means by a substance to exist absolutely when we inquire concerning the moon or the earth or a triangle or any other subject whether it is and then take some middle to demonstrate this. I say that a thing is something when we inquire concerning eclipse in regard to the moon, or equality or inequality in regard to triangle, or whether it is in the middle of the universe or not in regard to the earth. And he asserts that as far as the present point is concerned it makes no difference which way a thing is taken to be, because in all these cases what it is is the same as why.
Et hoc manifestat primo in defectu lunae. Si enim quaeratur quid est defectus lunae: respondetur quod est privatio luminis a luna propter terram, quae obiicitur inter ipsam et solem. Et hoc idem respondemus si quaeratur propter quid luna deficit. Dicimus enim quod luna deficit propter defectum luminis ex oppositione terrae.	He manifests this first of all in regard to the waning, of the moon. For if one asks what is the eclipse of the moon, the answer is that it is the absence of light in the moon because of the earth’s being set between it and the sun. And this same answer is given when it is inquired why the moon is eclipsed. For we say that the moon is eclipsed because there is a lack of light due to the earth’s opposition.
Et idem manifestat in alio exemplo. Si enim quaeratur quid est consonantia: respondetur quod est ratio, idest proportio numerorum secundum acutum et grave. Et rursum si quaeratur propter quid acutum consonat gravi: respondetur propter id quod habent numeralem proportionem acutum et grave. Sic ergo quaestio quid est et quaestio propter quid redeunt in idem subiecto, quamvis differant ratione. Unde quia cum quaeritur propter quid, quaeritur quid sit medium, ut ostensum est, relinquitur quod cum quaeritur quid est, similiter quaeratur medium.	Then he manifests the same idea with another example. For if one asks what is a chord, the answer is given that it is a numerical ratio according to high and low notes. Again, if one asks why a high note and a low note are concordant, the answer is given that it is because the high note and the low note have a numerical ratio. And so the question what is it and the question why reduce to the same thing subjectively, although they differ in formality. Hence because the question why leads us to inquire what the middle is, as has been shown, what is left is that when one asks what is it, the middle is likewise inquired.
Et idem ostendit in quaestione quia. Ut enim dictum est, consonantia est ratio in numeris acuti et gravis: cum ergo quaeritur utrum acutum et grave consonent, quaeritur utrum sit aliqua ratio numeralis acuti et gravis; et hoc est medium ad demonstrandum quod acutum et grave consonant. Relinquitur ergo quod in quaestione quia quaeritur an sit medium. Cum autem acceperimus quia est aliqua ratio numeralis acuti et gravis, quaeremus quae sit illa ratio. Et hoc est quaerere quid vel propter quid.	Then he shows the same thing in regard to the question that. For, as has been said, concordance is a numerical ratio between high and low notes. Men, therefore, one asks whether a high and low note concord, he is inquiring whether there is some numerical ratio of the high and low note; and this is the middle for demonstrating that a high and a low note concord. Consequently in the question that, one inquires whether there is a middle. But once we have found that there is a numerical ratio of the high and low note, we then ask what that ratio is: and this is to ask what or why.
lib. 2 l. 1 n. 9 Videtur hic Aristoteles dicere quod definitio passionis sit medium in demonstratione. Sed considerandum est quod definitio passionis perfici non potest sine definitione subiecti. Manifestum est enim quod principia, quae continet definitio subiecti, sunt principia passionis. Non ergo demonstratio resolvet in primam causam, nisi accipiatur ut medium demonstrationis definitio subiecti. Sic igitur oportet concludere passionem de subiecto per definitionem passionis, et ulterius definitionem passionis concludere de subiecto per definitionem subiecti. Unde et in principio dictum est quod oportet praecognoscere quid est, non solum de passione, sed etiam de subiecto; quod non oporteret nisi definitio passionis concluderetur de subiecto per definitionem subiecti.	Here Aristotle seems to say that the definition of a proper attribute is the middle in demonstration. However it must be remarked that the definition of the proper attribute cannot be completed without the definition of the subject. For it is obvious that the principles which the definition of the subject contains are the principles of the proper attribute. Hence a demonstration will not reach the first cause unless one takes as the middle of demonstration the definition of the subject. And so the proper attribute must be concluded of the subject by means of the definition of the proper attribute; furthermore, the definition of the proper attribute must be concluded of the subject through the definition of the subject. This is why it was laid down at the very beginning that one must know beforehand the what is it not only of the proper attribute but of the subject also; which would not be required unless the definition of the proper attribute were concluded of the subject through the definition of the subject.
Et hoc patet per exemplum. Si velimus de triangulo demonstrare quod habet tres angulos aequales duobus rectis, accipiamus primo pro medio quod est figura habens angulum extrinsecum aequalem duobus intrinsecis sibi oppositis, quod est quasi definitio passionis. Quod iterum demonstrare oportet per definitionem subiecti, ut dicamus: omnis figura tribus rectis lineis contenta habet angulum exteriorem aequalem duobus interioribus sibi oppositis; sed triangulus est huiusmodi; ergo et cetera. Et idem patet si velimus demonstrare quod vox acuta et gravis consonent: accipiemus definitionem passionis, ut hic dicitur, scilicet quod habent proportionem numeralem; sed rursus ad hoc demonstrandum oportet accipere definitionem gravis et acuti. Nam gravis vox est quae in multo tempore nata est movere sensum, acuta autem quae in modico tempore; modici autem ad multum est proportio numeralis; ergo vocis acutae et gravis est proportio numeralis. Nec refert si aliter definiatur acutum et grave. Oportet enim in eorum definitione ponere aliquid ad quantitatem pertinens; et sic necesse erit concludere in eis proportionem numeralem.	This is clear from the following example: If we wish to demonstrate of triangle that it has three angles equal to two right angles, we first take as middle the fact that it is a figure having an exterior angle equal to its two opposite interior angles-which is, as it were, the definition of a proper attribute. But this in turn must be demonstrated by the definition of the subject, so that we would say: “Every closed figure of three straight lines has an exterior angle equal to its two opposite interior angles; but the triangle is such a figure. Therefore...” And the same is true if we were to demonstrate that a high note concords with a low note: for we would state the definition of the attribute which in this case consists in their having a numerical ratio; but then to demonstrate this attribute we would have to take the definition of high note and of low note. For a low note is one which is apt to act on the sense for a long time, whereas a high note is one which does so for a short time: but between the long and the short there is a numerical ratio. Therefore, there is a numerical ratio between a high note and a low note. And if the high note and the low note were defined some other way, it would make no difference. For in any case something pertaining to quantity would have to appear in their definition, so that it would be necessary to conclude that there is a numerical ratio between them.
lib. 2 l. 1 n. 10 Deinde cum dicit: quod autem medii sit quaestio etc., ostendit propositum per signum sensibile. Et dicit quod ea in quibus medium est sensibile, manifeste ostendunt quod omnis quaestio sit quaestio medii: quia scilicet quando medium per sensum innotescit, nullus relinquitur quaestioni locus. Tunc enim quaerimus in rebus sensibilibus secundum aliquam praedictarum quaestionum, quando medium non sentimus: sicut quaerimus an sit defectus lunae vel non, quia non sentimus medium quod est causa faciens deficere lunam. Sed si essemus in loco qui est super lunam, videremus quomodo luna subintrando umbram terrae deficeret; et ideo circa hoc nihil quaereremus, nec si est nec propter quid est; sed simul utrumque nobis fieret manifestum.	Then (90a44) he manifests his point by means of a sensible sign. And he says that those cases in which the middle is perceptible by sense clearly show that every question is a question concerning a middle, because, namely, when the middle is known through the senses, no room is left for a question. For we ask one of the aforesaid questions in matters pertaining to sense, when the middle does not appear: thus, we ask whether or not there is an eclipse of the moon because we do not sensibly perceive the middle which is the cause making the moon to be eclipsed. But if we were to situate ourselves in a place above the moon, we would see how the moon became eclipsed by entering the earth’s shadow. Then we would no longer ask if it is or why it is, but both would at once be obvious to us.
lib. 2 l. 1 n. 11 Et quia posset aliquis obviando dicere quod sensus est singularium, ea vero quae quaeruntur sunt universalia, sicut et ea quae sciuntur; et ita per sensum non videtur quod possit nobis innotescere id de quo est quaestio: ideo quasi obviationi respondens subiungit quod ex hoc ipso quod sentiremus particulare, scilicet quod, hoc corpus lunae tunc subintrat hanc umbram terrae, statim accideret nobis quod sciremus universale. Sensus enim noster esset de hoc quod nunc lumen solis obstruitur per oppositionem terrae; et per hoc manifestum esset nobis quod luna nunc deficit. Et quia nos coniiceremus quod semper hoc modo accideret lunae defectus, statim in nostra scientia sensus rei singularis fieret universale.	But because someone could object that sense-perception bears on singulars—whereas it is universals that are being asked about, just as it is universals that are scientifically known—and consequently, it does not seem that the matter under question can be made known through sense; therefore, as though in answer to this objection he adds that it is precisely because we do sense the particular (namely, that this body of the moon enters this shadow of the earth), that we happen at once to know the universal. For our sense would observe the fact that the light of the sun is now blocked by the earth’s opposition; and through this it would be clear to us that the moon is now eclipsed. And because we would conjecture that the eclipse of the moon always occurs in this way, the sense knowledge of the singular would immediately become a universal in our science.
Et ex hoc exemplo concludit quod idem est scire quod quid est et propter quid. Nam ex hoc quod videmus terram interpositam inter solem et lunam, sciremus et quid est defectus lunae et propter quid luna deficit: quorum unum, scilicet scire quid est, refertur ad scientiam qua scimus de aliquo quod simpliciter sit, non autem quod aliquid insit alicui; sed propter quid refertur ad cognitionem eorum quae insunt, sicut cum dicimus quod tres anguli sunt aequales duobus rectis, aut maiores aut minores. Ultimo autem epilogando concludit principale propositum, scilicet manifestum esse ex praedictis, in omnibus quae quaeruntur esse medii quaestionem.	And so from this example he concludes that knowing the quod quid [quod quid refers to any or all of the items that constitute the essential nature of a thing.] and the why are the same. For from the fact that we observe the earth situated between the sun and moon, we would know scientifically both what an eclipse of the moon is and why the moon is eclipsed. And one of these, namely, the knowledge what it is, is reduced to the science by which we know that something simply is, and not that something is in some thing. But the why is reduced to our knowledge of things that are in some thing, as when we say that three angles are equal to or greater than or less than two right angles. Finally, he summarizes and concludes the main point, namely, that it is clear from the foregoing that in all questions there is question of the middle.

Lecture 2 Whether the definition which signifies the quod quid of a thing can be demonstrated

Latin	English
	Lecture 2 (90a36-91a3) WHETHER THE DEFINITION WHICH SIGNIFIES THE QUOD QUID OF A THING CAN BE DEMONSTRATED
lib. 2 l. 2 n. 1 Postquam philosophus ostendit quod omnis quaestio est quodammodo quaestio medii, quod quidem est quod quid est et propter quid, hic incipit manifestare qualiter medium nobis innotescat; et dividitur in partes duas: in prima parte ostendit quomodo quod quid est et propter quid se habent ad demonstrationem; in secunda parte ostendit quomodo oporteat investigare quod quid est et propter quid; ibi: quomodo autem oportet venari et cetera. Prima autem pars dividitur in partes duas: in prima, manifestat quomodo se habeat ad demonstrationem ly quid est; in secunda, manifestat quomodo se habeat ad demonstrationem ly propter quid, quod significat causam; ibi: quoniam autem scire opinamur cum sciamus causam et cetera.	After showing that every question is in some sense a question of the middle, which is the quod quid and the propter quid, the Philosopher now begins to make manifest how the middle becomes known to us. And it is divided into two parts. In the first part he shows how the quod quid and propter quid are related to demonstration. In the second part he shows how the quod quid and propter quid should be investigated (96a22) [L. 13]. The first part is divided into two parts. In the first he manifests how the quid est is related to demonstration. In the second he manifests how the propter quid which signifies a cause is related to demonstration (94a20) [L. 9]. In regard to the first he does two things. First, he states his proposal. Secondly, he pursues his proposal (90b1).
lib. 2 l. 2 n. 2 Circa primum duo facit: primo, dicit de quo est intentio; secundo, prosequitur propositum; ibi: principium autem sit futurorum et cetera. Dicit ergo primo quod quia omnis quaestio, ad cuius determinationem demonstratio inducitur, est quaestio medii, quod est quid et propter quid, oportet primo dicere per quem modum hoc ipsum quod quid est nobis ostendatur, utrum scilicet per demonstrationem, vel per divisionem, vel quovis alio modo. Et iterum oportet dicere quis sit modus reducendi ea quae apparent de re, ad quod quid est. Et quia definitio est oratio significans quod quid est, oportet etiam scire quid sit definitio et quae sint definibilia. In his autem hoc ordine procedemus: primo quidem opponendo; secundo autem veritatem determinando.	He says therefore first (90a36) that since every question for whose solution a demonstration is adduced is a question of the middle which is quid and propter quid, our first task is to declare how the quod quid is made known to us, namely, is it through demonstration or division or some other way. Furthermore, we must point out how to reduce to the quod quid those items of a thing that are apparent. And because a definition is a statement which signifies the quod quid, it is necessary also to know what a definition is and why certain things are definable. Consequently we shall proceed in these matters in the following way. First, by raising difficulties. Secondly, by establishing the truth (93a1) [L. 7]. Then (90b1) he pursues his proposal in the order stated. First, he proceeds dialectically by raising difficulties. Secondly, by determining the truth (93a1) [L. 7].
lib. 2 l. 2 n. 3 Deinde cum dicit: principium autem sit futurorum etc., exequitur propositum ordine praedicto. Unde primo, procedit circa praemissa disputative opponendo; secundo, veritatem determinando; ibi: iterum autem speculandum est quid horum et cetera. Circa primum duo facit: primo, procedit disputando de ipsa definitione, quae significat quod quid est; secundo, de ipso quod quid est per definitionem significato; ibi: ipsius autem quid est utrum syllogismus et cetera. Circa primum tria facit: primo, inquirit disputative utrum omnium quorum est demonstratio, sit definitio; secundo, utrum e converso omnium quorum est definitio, sit demonstratio; ibi: quid autem cuius est definitio etc.; tertio, utrum alicuius eiusdem sit definitio et demonstratio; ibi: sed utrum si non omnis et cetera.	In regard to the first he does two things. First, he proceeds by disputing about the definition which signifies quod quid. Secondly, about the quod quid which is signified by the definition (91a12) [L. 31. Concerning the first he does three things. First, he inquires disputatively whether there is definition of all things of which there is demonstration. Secondly, whether conversely there is demonstration of all things of which there is definition (91b19). Thirdly, whether there can be definition and demonstration of the same thing (90b27).
Circa primum duo facit: primo, dicit de quo est intentio; secundo, exequitur propositum; ibi: dubitabit enim utique aliquis et cetera. Dicit ergo primo quod inter ea quae in futurum dicenda sunt, principium oportet sumere ab eo quod est convenientissimum habitarum, idest consequentium rationum. Quod quidem est de hoc quod posset aliquis dubitare utrum contingat idem et secundum idem scire per definitionem et demonstrationem.	In regard to the first he does two things. First, he states his intention. Secondly, he pursues his proposal (90b1). He says therefore first (90b1) that when a number of items are planned for discussion, one should take his start from the item which is most fruitful in settling the “had,” i.e., the subsequent, problems. This would mean that in our case we should begin with the fact that someone might wonder whether the same thing and according to the same aspect could be known through definition and demonstration.
lib. 2 l. 2 n. 4 Deinde cum dicit: definitio quidem enim quod quid est etc., probat quod non omnium quorum est demonstratio, sit definitio. Et hoc quadrupliciter. Primo quidem, quia definitio est indicativa eius quod quid est; omne autem quod pertinet ad quod quid est, praedicatur et affirmative et universaliter; ergo definitio est solum eorum contentiva sive significativa, quae praedicantur affirmative et universaliter. Sed non omnes syllogismi sunt demonstrativi conclusionum affirmativarum universalium; sed quidam sunt negativi, puta omnes qui sunt in secunda figura; quidam vero particulares, puta omnes qui sunt in tertia figura. Non ergo omnium est definitio, quorum est demonstratio.	Then (90b4) he proves that there is not definition of all things of which there is demonstration. This he does in four ways, the first of which is the following: a definition is indicative of the quod quid; but anything which pertains to the quod quid is predicated both affirmatively and universally: therefore, a definition contains or signifies only those things which are predicated affirmatively and universally. But not all syllogisms demonstrate affirmative universal conclusions: in fact some are negative, as for example, all those in the second figure; and some are particular, as for example, all those in the third figure. Therefore, there is not definition of all things of which there is demonstration.
lib. 2 l. 2 n. 5 Secundo, ibi: postea neque eorum quae sunt etc., ostendit idem dicens quod neque definitio etiam potest esse omnium eorum quae concluduntur per syllogismos affirmativos, quod contingit esse solum in prima figura, sicut demonstrative syllogizatur quod omnis triangulus habet tres angulos aequales duobus rectis. Huius autem quod dictum est, scilicet quod non omnium quae sic syllogizantur, possit esse definitio, ratio est, quia scire aliquid demonstrative nihil aliud est quam demonstrationem habere. Ex quo patet quod si omnium horum scientia solum per demonstrationem habetur, non est eorum definitio. Ea enim quorum est definitio, cognoscuntur per definitionem. Sequeretur igitur quod aliquis non habens horum demonstrationem sciret ea; eo quod nihil prohibet aliquem habentem definitionem non simul habere demonstrationem; quamvis definitio sit demonstrationis principium. Non enim quicunque cognoscit principia, scit conclusionem deducere demonstrando.	Secondly (90b7), he shows the same thing when he says that there cannot even be definition of all things which are concluded through affirmative syllogisms-which occurs only in the first figure, as when it is demonstratively syllogized that every triangle has three angles equal to two right angles. Now the reason for this statement, namely, that there cannot be definition of all things thus syllogized, is that to know something demonstratively is nothing else than to have a demonstration. From this it follows that if the science of all these things is had only through demonstration, there is not definition of them. For things which have a definition are made known through their definition. Otherwise it would follow that a person who does not have a demonstration of these things would have scientific knowledge of them, for the simple reason that nothing hinders a person who knows the definition from not having at the same time the demonstration-although the definition is a principle of the demonstration. For not everyone who knows the principles knows how to deduce the conclusion by demonstrating.
lib. 2 l. 2 n. 6 Tertio, ibi: sufficiens autem fides est etc., ostendit idem per inductionem, ex qua potest fieri praemissae conclusionis sufficiens fides: quia demonstratio est eorum quae per se insunt, ut patet ex his quae in primo habita sunt. Nullus autem unquam cognovit per definitionem neque aliquid eorum quae per se insunt, neque etiam aliquid eorum quae per accidens insunt; non quod accidentium, quae per se vel per accidens insunt, non possunt esse aliquae definitiones, ut habetur in VII Metaph.; sed quia eius quod est inesse per se vel per accidens, quod syllogismus concludit, nullus unquam dedit definitionem.	Thirdly (9014), he shows the same thing through an induction from which a conviction can arise sufficient for admitting the above-mentioned conclusion. He says, therefore, that demonstration is concerned with things which are per se in something, as is clear from what has been established in the first book. But a definition never gives anyone a knowledge of those items which are per se in a thing, much less of those which are in it per accidens-not that there cannot be definitions of accidents which are in a thing per se or per accidens; but because no one has ever given the definition of that which is to be in a thing per se or per accidens, which the syllogism concludes.
lib. 2 l. 2 n. 7 Quarto, ibi: amplius si definitio substantiae etc., ostendit idem per rationem, quia definitio est notificatio substantiae: tum quia substantia principaliter definitur, accidens vero per posterius, definitione quae est per additamentum, ut habetur in VII Metaph.; tum etiam quia accidens non definitur, nisi quatenus significatur per modum substantiae per aliquod nomen. Haec autem de quibus sunt demonstrationes, non sunt substantiae, nec per modum substantiae significantur, sed per modum accidentium, scilicet secundum inesse aliquid alicui. Unde concludit non esse possibile quod definitio sit omnis eius cuius est demonstratio.	Fourthly (90b16), he shows the same thing with a reason, namely, that the definition makes the substance known: first of all, because substance is defined in a primary way, whereas accident is defined secondarily by means of a definition which adds something alien, as is stated in Metaphysics VII; and secondly, because an accident is not defined save insofar as it is signified after the manner of a substance by employing a noun. But the things upon which demonstrations bear are not substances nor things signified after the manner of substances, but things signified after the manner of accidents, namely, after the manner of something inhering in some thing. Hence he concludes that it is not possible that there be a definition of everything of which there is demonstration.
lib. 2 l. 2 n. 8 Deinde cum dicit: quid autem cuius est definitio etc., inquirit an e converso demonstratio sit omnis eius cuius est definitio. Et ostendit quod non, duplici ratione; quarum prima iam supra tacta est. Unius enim, in quantum est unum, videtur esse una scientia, idest unus modus cognoscendi. Unde si id quod est demonstrabile, vere scitur per hoc quod habetur demonstratio de eo, sequitur quoddam impossibile si per definitionem sciri possit; quia habens definitionem sciret aliquid demonstrabile absque hoc quod haberet demonstrationem: quod videtur inconveniens. Et haec ratio fuit secundo posita inter praemissas.	Then (90b19) he inquires whether conversely there is demonstration of everything of which there is a definition. And he shows that there is not for two reasons, the first of which has already been touched upon above. For it seems that of one thing, precisely as it is one, there is one science, i.e., one way of knowing it. Hence if that which is demonstrable is truly known scientifically in virtue of the fact that a demonstration is had of it, then something impossible follows, if it can also be scientifically known through a definition: for the one having the definition would be knowing something demonstrable without having the demonstration-which seems absurd. And this reason was the second of the four previously presented.
lib. 2 l. 2 n. 9 Secundam rationem ponit ibi: amplius principia demonstrationum et cetera. Definitiones enim sunt principia demonstrationum, ut in primo habitum est; sed principia non sunt demonstrabilia, quia sic sequeretur quod principiorum essent principia, et quod demonstrationes in infinitum procederent; quod est impossibile, ut in primo ostensum est. Unde sequitur quod definitiones sint indemonstrabiles, tanquam quaedam prima principia in demonstrationibus. Et sic non omnium quorum est definitio, est demonstratio.	Then (90b23) he gives the second reason. For definitions are principles of demonstrations, as was established in Book I; but the principles are not demonstrable—otherwise it would follow that there are principles of principles and that demonstrations would proceed to infinity, which is impossible, as we have shown in the first book. Hence it follows that definitions are not demonstrable, being as they are first principles in demonstrations. Consequently, there is not demonstration of all things of which there is definition.
lib. 2 l. 2 n. 10 Deinde cum dicit: sed utrum si non omnis etc., inquirit utrum sit possibile quod alicuius eiusdem sit definitio et demonstratio, etsi non omnis eiusdem. Et ostendit quod non, tribus rationibus. Quarum prima est, quia definitio est manifestativa eius quod quid est et substantiae, idest essentiae cuiuslibet rei. Demonstrationes autem hoc non manifestant, sed supponunt; sicut in mathematicis demonstrationibus arithmeticae supponitur quid est unitas et quid est impar; et simile est etiam in aliis demonstrationibus. Ergo non est eiusdem demonstratio et definitio.	Then (90b28) he inquires whether it is possible for there to be definition and demonstration of the same thing in some cases even though not of all. And with three reasons he shows that there is not. The first of these reasons is that a definition is manifestive of the quod quid and of the substance, i.e., of the essence, of a thing. Demonstrations, on the other hand, do not manifest this but suppose it: thus in mathematical demonstrations it is supposed from arithmetic what unity is and what odd is; and the same applies in other demonstrations. Therefore, there is not demonstration and definition of the same thing.
lib. 2 l. 2 n. 11 Secundam rationem ponit ibi: amplius omnis demonstratio etc.; quae talis est. In eo quod per demonstrationem concluditur, praedicatur aliquid de aliquo vel affirmative vel negative: sed in definitione non praedicatur aliquid de aliquo; sicut in hac definitione, homo est animal bipes, neque animal praedicatur de bipede, neque bipes de animali. Et similiter in hac definitione, circulus aut triangulus est figura plana, nec planum praedicatur de figura, neque e converso. Si enim partes definitionis adiungerentur sibi invicem, oporteret quod praedicatio intelligeretur per modum convenientem definitioni, scilicet in eo quod quid est. Hoc autem non videmus. Nec enim genus praedicatur in eo quod quid est de differentia, neque e converso. Non ergo eiusdem est definitio et demonstratio.	Then (90b33) he presents the second reason and it is this: In the conclusion of a demonstration something is predicated of something either affirmatively or negatively; but in a definition nothing is predicated of anything: thus in the definition that man is a two-footed animal, neither animal is predicated of two-footed nor two-footed of animal. Likewise in the definition that a circle or a triangle is a plane figure, neither plane is predicated of figure nor figure of plane. For if the parts of a definition were to be joined to one another, the resulting predication would have to be understood in a manner which suits a definition, namely, in quod quid. But this we do not observe. For the genus is not predicated quod quid of the difference, nor the difference of the genus. Therefore, there is not definition and demonstration of a same thing.
lib. 2 l. 2 n. 12 Tertiam rationem ponit ibi: amplius alterum est quod quid est etc.; et dicit quod alterum est manifestare quod quid est et quia est, ut patet in differentia quaestionum supra posita: sed definitio ostendit de aliquo quid est; demonstratio autem ostendit affirmative vel negative aliquid esse de aliquo vel non esse. Videmus autem quod alterius rei alia est demonstratio, nisi illa duo se habeant ad invicem sicut totum et pars; quia tunc una et eadem esset demonstratio de utroque. Sicut demonstrato quod triangulus habet tres angulos aequales duobus rectis, similiter etiam ostensum est de isoscele, qui se habet ad triangulum sicut pars ad totum. Sed non ita est in his duobus, quia est et quid est: neutrum enim est pars alterius.	Then (90b38) he gives the third reason and says that it is one thing to manifest the quod quid and another the quia, as is clear from the difference between the questions listed above; but the definition shows the quid of something, whereas a demonstration shows either affirmatively or negatively that something is or is not so of something. But we see that for different things different demonstrations are required, unless those two different things are related as whole and part: for in that case there would be one and the same demonstration concerning both. Thus, the demonstration that a triangle has three angles equal to two right angles applies also to isosceles, which is related to triangle as part to whole. But that is not the case in these two things, namely, in the quia and in the quid; for neither is a part of the other.
lib. 2 l. 2 n. 13 Ostensum est igitur quod nec omnis cuius est definitio, sit demonstratio, neque e converso. Et ex hoc ulterius concludi potest quod nullius eiusdem sint; et quod definitio et demonstratio neque sint idem, neque unum sit in alio sicut pars subiectiva in suo toto; quia oporteret quod etiam ea quorum sunt, se haberent per modum totius et partis, ita scilicet quod omne definibile esset demonstrabile, aut e converso. Quod supra improbatum est. Ultimo epilogando concludit usque ad hoc processum esse opponendo.	Therefore, it has been established that there is not demonstration of everything of which there is definition, nor conversely. Furthermore, it has been possible from this to conclude that these are not of the same thing, and that definition and demonstration are neither the same nor is one in the other as a subjective part in its whole—otherwise it would be necessary that even those things of which they are be related after the manner of whole and part in such a way, namely, that everything definable would be demonstrable, or vice versa—which was disproved above. Finally, he summarizes and concludes that so far we have proceeded by opposing.

Lecture 3 Whether the quod quid signified by the definition can be demonstrated by taking convertible terms

Latin	English
	Lecture 3 (91a12-b11) WHETHER THE QUOD QUID SIGNIFIED BY THE DEFINITION CAN BE DEMONSTRATED BY TAKING CONVERTIBLE TERMS
lib. 2 l. 3 n. 1 Postquam philosophus disputative inquisivit utrum definitio significans quod quid est possit demonstrari, hic procedit ulterius ad inquirendum disputative utrum ipsum quod quid est, quod est definitionis significatum, possit demonstrative probari.	After inquiring disputatively whether the definition signifying quod quid can be demonstrated, the Philosopher continues to inquire disputatively and asks whether the quod quid itself, which is signified by a definition, can be proved demonstratively. First, he states what he intends. Secondly, he pursues his proposal (91a14).
Et primo, proponit quod intendit; secundo, exequitur propositum; ibi: syllogismus quidem enim et cetera. Movet ergo primo quaestionem: utrum possit esse syllogismus aut demonstratio eius quod quid est, ita scilicet quod concludatur hoc esse quod quid est huius; aut hoc non sit possibile, sicut supposuit ratio immediate praemissa?	First, therefore (91a12), he raises the question: Can there be a syllogism or demonstration of that which is the quod quid, namely, in such a way as to conclude that this is the quod quid of this; or can this not be done, as the immediately preceding reason supposed?
lib. 2 l. 3 n. 2 Fuit autem necessaria haec disputatio post praemissam, quia in definitione attenditur non solum ut illud quod significatur, sit quod quid est, sed etiam ut tali modo tradatur qui competat ad manifestandum quod quid est; ita scilicet quod sit ex prioribus et notioribus, et alia huiusmodi habeat quae in definitione sunt observanda. Signanter autem dicit, utrum sit syllogismus aut demonstratio: nam rationum subsequentium quaedam concludunt quod eius quod quid est non sit demonstratio, quaedam vero quod eius omnino non sit syllogismus.	Now it was necessary to undertake this disputation on the heels of the previous one, because in a definition one must be sure not only that what it signifies is the quod quid, but also that it be formulated in such a. way as to be suitable for manifesting the quod quid, i.e., in such a way as to be composed of prior and better known items and possess the other diaracteristics which mark a definition. It is significant that he says, .1 whether there be syllogism or demonstration,” for some of the reasons which follow conclude that there is not demonstration of the quod quid, and others that there is no syllogism at all of it.
lib. 2 l. 3 n. 3 Deinde cum dicit: syllogismus quidem enim aliquid de aliquo etc., procedit disputative ad ostendendum quod non sit syllogismus vel demonstratio eius quod quid est. Et primo, excludit quosdam speciales modos, quibus posset videri quod possit demonstrari quod quid est; secundo, ponit rationes communes ad hoc; ibi: amplius quomodo demonstrabit et cetera. Circa primum tria facit: primo, ostendit quod non potest demonstrari quod quid est per acceptionem convertibilium terminorum; secundo, quod non potest demonstrari per divisionem; ibi: at vero neque per divisionem etc.; tertio, quod non potest demonstrari accipiendo id quod requiritur ad quod quid est; ibi: sed utrum sit demonstrare et cetera.	Then (91a14) he proceeds disputatively to show that there is not sy1logism, or demonstration of the quod quid. First, he excludes certain special ways by which it might seem possible to demonstrate the quod quid. Secondly, he presents common reasons for this (953) [L. 6]. Concerning the first he does three things. First, he shows that quod quid cannot be demonstrated by using convertible terms. Secondly, that it cannot be demonstrated by division (91b12) [L. 4]. Thirdly, that it cannot be demonstrated by accepting that which is required for quod quid (92a6) [L. 51.
Circa primum tria facit: primo, praemittit quaedam quae sunt necessaria ad propositum ostendendum; secundo, inducit rationem; ibi: si enim ipsius ca proprium est etc.; tertio, manifestat inconveniens quod sequitur; ibi: oportet autem in duabus propositionibus et cetera.	In regard to the first he does three things. First, he prefaces certain notions required for showing the proposal. Secondly, he induces a reason (91a17). Thirdly, he discloses the inconvenience which follows (91a32).
lib. 2 l. 3 n. 4 Circa primum praesupponit duo. Quorum primum pertinet ad syllogismum, scilicet quod omnis syllogismus probat aliquid de aliquo per aliquod medium, ut ex superioribus patet. Aliud autem pertinet ad ipsum quod quid est, quod est per syllogismum probandum; ad quod requiruntur duae conditiones. Quarum una est quod quod quid est sit proprium: quaelibet enim res habet propriam essentiam sive quidditatem. Et quia non omne quod est proprium alicui pertinet ad essentiam eius, sicut risibile homini; ideo requiritur secunda conditio, quod praedicetur in quid. Et has duas conditiones necesse est sequi tertiam, scilicet ut quod quid est sit convertibile cum eo cuius est.	With respect to the first (9104) he presupposes two things: the first of these pertains to the syllogism, namely, that every syllogism proves something about something by means of some middle, as is clear from the above. The other pertains to what is to be proved by the syllogism, namely, the quod quid, for which two conditions are required. The first of these is that the quod quid be proper, for each thing has its own proper essence or quiddity. But because not everything which is proper to something pertains to its essence, a second condition is required, namely, that it be predicated in quid. Furthermore, a third condition must follow on these two, namely, that the quod quid be convertible with that of which it is.
lib. 2 l. 3 n. 5 Deinde cum dicit: si enim a ipsi c est proprium etc., ponit rationem ad propositum ostendendum. Et circa hoc tria facit: primo, dicit qualem oporteat esse syllogismum qui concludit quod quid est, si hoc sit possibile; secundo, concludit inconveniens, quod ex hoc sequitur; ibi: si ergo quod quid est etc.; tertio, exemplificat in terminis; ibi: et omnino si est monstrare et cetera. Circa primum tria facit: primo enim ostendit quid requiratur ad syllogismum concludentem quod quid est, ex eo quod est proprium; secundo, quid requiratur ex eo quod praedicatur in quid; ibi: at vero et si a etc.; tertio, ostendit quod sine his talis syllogismus esse non possit; ibi: si vero aliquis et cetera.	Then (91a17) he lays down a reason in support of his proposal. Regarding this he does three things. First, he states what sort of syllogism would be required for concluding a quod quid, if this were possible. Secondly, he concludes to the inconvenience that follows from this (9145). Thirdly, he uses terms to exemplify this (91a28). Concerning the first he does three things. First, he shows what is required for a syllogism concluding the quod quid so far as it is something proper. Secondly, what is required so far as it is predicated in quid (9108). Thirdly, he shows that without these characteristics such a syllogism would not be possible (91a21).
Dicit ergo primo quod si a, quod est probandum de c tanquam quod quid est eius, est proprium ipsi c (quod requiritur ad quod quid est, ut dictum est), oportebit quod primum, scilicet a, sit proprium medio, quod est b: nam si a excedit b, quod universaliter praedicatur de c, sequitur quod a multo magis excedat c. Et similiter manifestum est quod oportebit b esse proprium ipsius c: nam si b excedat c, sequitur quod a, quod praedicatur universaliter de b, excedat c; et sic non erit proprium eius, ut supponebatur. Relinquitur ergo quod si aliquis syllogismus sit, qui concludit quod quid est, oportet esse talem habitudinem terminorum eius, ut omnes ad invicem convertantur.	He says therefore first (9108) that if A which is to be proved of C as its quod quid is proper to C (which is required of the quod quid, as has been said), it will be necessary that the first, namely, A, be proper to the middle which is B; for if A exceeded [i.e., were more universal than] B, which is predicated universally of C, it would follow that A exceeds C even more. In like manner, it is clear that B will have to be proper to C: for if B were to exceed C, it would follow that A, which is predicated universally of B, exceeds C; consequently, it would not be proper to it, as was supposed. What remains, therefore, is that if there is to be a syllogism concluding quod quid, the terms will have to be so related that all are mutually convertible.
lib. 2 l. 3 n. 6 Deinde cum dicit: at vero et si a in eo quod quid est etc., ostendit quid debeat habere syllogismus praedictus, ex eo quod concludit id quod praedicatur in eo quod quid est. Et dicit quod oportet hoc modo syllogismum procedere, ut maior extremitas, quae est a, praedicetur in eo quod quid de medio, quod est b; et b similiter praedicetur in eo quod quid de minori extremitate, quae est c; et sic concluditur quod a praedicetur de c in eo quod quid est.	Then (91a18) he shows what the syllogism in question must have, if the condition is to be fulfilled that what it concludes be predicated in quod quid. And he says that such a syllogism must be so formulated that the major extreme, which is A, be predicated in quod quid of the middle, which is B; in like manner, B will have to be predicated in quod quid of the minor extreme, which is C. In this way it can be concluded that A is predicated of C in quod quid.
lib. 2 l. 3 n. 7 Deinde cum dicit: si vero aliquis non accepit sic duplicans etc., ostendit quod praedictus modus syllogizandi requiratur. Et dicit quod si aliquis non ita accipiat terminos duplicans, idest observans duas conditiones praedictas, vel potius accipiens quod quid est ex duabus partibus, non sequitur ex necessitate quod a praedicetur de c in eo quod quid est. Sed et si ex una tantum parte praedictae conditiones observentur, non sufficit ad propositum. Etsi enim detur quod a praedicetur de b in eo quod quid est, non propter hoc sequitur quod praedicetur in eo quod quid de quibuscunque praedicatur b qualitercunque. Et sic sequitur quod ex utraque parte oporteat accipere quod quid est: ita scilicet quod non solum a sit quod quid est ipsius b, sed etiam ipsum b sit quod quid est ipsius c, tanquam convertibiliter et in eo quod quid praedicatum.	Then (91a21) he shows that the aforesaid way of syllogizing is required. And he asserts that if one does not so take the terms by “thus duplicating,” i.e., observing the two conditions laid down above, i.e., taking the quod quid on the side of both, it does not follow of necessity that A would be predicated of C in quod quid. Indeed, if the aforesaid conditions are observed on the part of one only, it is not sufficient for the purpose intended. For even if A were predicated of B in quod quid, it would not on that account follow that it must be predicated in quod quid of everything of which B might happen to be predicated in some random way. Consequently, it follows that the quod quid must be taken on the side of both in such a way, namely, that not only must A be the quod quid of B, but also that B must be the quod quid of C, as being predicated convertibly and in quod quid.
lib. 2 l. 3 n. 8 Deinde cum dicit: si igitur quod quid est et quod quid erat esse etc., ducit ad inconveniens: quia si, sicut ostensum est, ex utraque parte invenitur non solum praedicari aliquid in eo quod quid, sicut genus praedicatur de specie, sed etiam quod ex utraque parte sit quod quid erat esse, quod significat definitio, sequitur quod quid erat esse prius fuisse in medio termino; idest quod medius terminus sit quod quid erat esse minoris extremitatis: et ita supponitur quod oportebat probare, scilicet quidditatem ipsius c.	Then (91a25) he leads to the inconvenience: for if, as has been indicated, not only is there found on the side of both something which is predicated in quod quid-as a genus predicated of a species-but it is further found on the side of both that this something is the quod quid erat esse-which a definition signifies-it follows that the quod quid erat esse was already in the middle term, i.e., that the middle term is the quod quid erat esse of the minor extreme. Consequently, we would have been supposing the very thing we had set out to prove, namely, the quiddity of C. [quod quid erat esse refers to the essential nature of a being.]
lib. 2 l. 3 n. 9 Deinde cum dicit: et omnino si est monstrare quid etc., manifestat quod dixerat in terminis. Puta si volumus monstrare quid est homo, sit c, idest minor extremitas, homo; a vero, idest maior extremitas, sit quod quid est hominis, puta animal bipes, vel aliquid aliud huiusmodi. Si ergo hoc oporteat per syllogismum probari, necesse est quod definiatur aliquod medium, scilicet b, de quo omni a praedicetur; et ad hoc medium pertinebit quaedam alia media definitio, quae scilicet erat definitio minoris extremitatis. Unde sequetur quod hoc etiam medium sit quod quid est hominis. Et ita qui sic syllogizat, accipit supponendo id quod oportebat ostendere, scilicet quod b sit quod quid erat esse hominis.	Then (91a28) he clarifies what he has just said, using terms. Thus, if we wish to show what man is, let C, i.e., the minor extreme, be “man,” and A, the major extreme, be the “quod quid of man,” say “two-footed animal,” or something similar to this. Therefore, if this is what we intend to prove by the syllogism, it is necessary to find the definition of some middle, namely, B, such that A will be predicated of every B. Furthermore, to this middle will pertain some other middle definition which, namely, was the definition of the minor extreme. Hence it will follow that this middle will also be the quod quid of man. Consequently, one who syllogizes in this way would be supposing what he was required to prove, namely, that B is the quod quid erat esse of man.
lib. 2 l. 3 n. 10 Deinde cum dicit: oportet autem in duabus etc., manifestat quomodo hoc inconveniens sequatur ex praemissis. Et circa hoc tria facit. Primo, ostendit modum quo convenienter hoc manifestetur. Et dicit quod id quod dictum est, oportet considerare in duabus propositionibus, quae sint primae et habeant terminos immediate sibi inhaerentes. Possibile enim esset per plures propositiones hoc ostendere, ex quibus plures syllogismi constarent; vel etiam esset possibile duas solas propositiones accipiendo, accipere eas mediatas. Sed quia oportet semper reducere ad duas primas immediatas, ideo, ut brevior et expeditior sit consideratio, assumamus a principio tales propositiones, et sic maxime poterit manifestari propositum.	Then (91a32) he shows how this inconvenience follows from the premises. To this end he does three things. First, he indicates the method by which this may be fittingly done. And he says that what has been said should be considered in two propositions which are first and which have terms that belong to each other immediately. For it would be possible to prove our point either with several propositions (which would lead to several syllogisms), or with only two propositions, but taking them as mediate. But because in the final analysis we must always arrive at two immediate propositions, then for the sake of brevity and dispatch let us assume such propositions from the very start. Thus we shall be able to manifest our point quite easily.
lib. 2 l. 3 n. 11 Secundo, ibi: qui quidem itaque per conversionem etc., proponit quod intendit; et dicit, concludens ex praemissis, quod illi qui volunt demonstrare per terminos convertibiles quod quid est alicuius rei, puta quid est anima, vel quid est homo, vel quodcunque aliud huiusmodi, necesse est quod incidant in hoc quod petant principium. Et inducit exemplum de definitione animae secundum Platonem. Quia enim anima vivit, et est corpori causa vivendi, sequitur quod differat a corpore per hoc quod corpus vivit per aliam causam, anima vero vivit per seipsam.	Secondly (91a35), he states what he intends and says, concluding from the foregoing, that those who would demonstrate through convertible terms the quod quid of some thing (say, what is a soul, or what is man, or anything else of this sort), necessarily commit the fault of begging the question. And he cites as an example Plato’s definition of soul. For since the soul is alive and is the body’s cause of being alive, it follows that it differs from the body in the fact that the body lives in virtue of some cause other than itself, but the soul lives in virtue of itself. But Plato posited that number is the substance of all things: for he failed to distinguish between one, which is converted with being and refers to the substance of that of which it is predicated, and one which is the principle of number. As a consequence, it followed that the soul as to its substance is a number, just as any other thing containing many things in itself.
Ponebat autem Plato quod numerus est substantia omnium rerum: eo quod non distinguebat inter unum quod convertitur cum ente, quod significat substantiam eius de quo dicitur, et unum quod est principium numeri; et ita sequebatur quod anima substantialiter sit numerus, sicut et quaelibet alia res multa in se continens. Item ponebat Plato quod vivere sit quoddam moveri. Duobus enim distinguitur vivum a non vivente, scilicet sensu et motu, ut dicitur in I de anima; et ipsum sentire sive cognoscere dicebat esse quoddam moveri. Sic ergo dicebat animam esse numerum seipsum moventem: dicebat etiam animam esse id quod est sibi causa vivendi. Si quis ergo velit probare quid est anima, quia scilicet est id quod est sibi causa vivendi, et assumat pro medio quod anima est numerus seipsum movens, necesse est hoc petere, scilicet quod anima sit numerus seipsum movens: ita scilicet quod hoc sit idem ipsi animae, tanquam quod quid est eius. Alioquin non sequeretur quod si aliquid est quod quid est numeri moventis seipsum, quod sit quod quid est ipsius animae.	Likewise Plato posited that to live is one of the ways of being moved. For the living are distinguished from the non-living on two scores, namely, sense and movement, as it is stated in On the Soul I. Furthermore, he asserted that sensing or knowing is one way of being moved. Thus, therefore, he said that the soul is a self-moving number in addition to saying that the soul is its own cause of being alive. Consequently, if anyone desired to prove what a soul is, namely, that it is something which is its own cause of being alive, and assumed as middle that the soul is a number which moves itself, it would be necessary to beg this, namely, that the soul is a self-moving number, such that this is identical with the soul as being its quod quid. Otherwise, it would not follow, if something is the quod quia of self-moving number, that it is the quod quid of the soul itself.
lib. 2 l. 3 n. 12 Tertio, ibi: non enim si consequitur etc., probat propositum, scilicet quod talis probatio contineat petitionem principii; et dicit quod non sequitur quod maior extremitas, quae est a, sit quod quid est minoris extremitatis, quae est c, ex hoc quod a sequitur ad b et b sequitur ad c; sed sequitur simpliciter quod a insit c. Et si ulterius detur quod ipsum a sit quod quid est alicuius, et praedicetur universaliter de b, non adhuc sequitur quod a sit quod quid est ipsius c: manifestum est enim hoc quod est animali esse, idest quod quid est animalis, praedicari de hoc quod est homini esse, idest de eo quod est quod quid est hominis. Sicut enim verum est quod animal universaliter praedicatur de homine, ita verum est quod definitio animalis universaliter praedicetur de definitione hominis, non tamen ut sint omnino unum et idem.	Thirdly (91b1), he proves his proposal, namely, that such a proof involves begging the question. And he says that it does not follow from the fact that A follows on B and B on C, that the major extreme, A, is the quod quid of the minor extreme, C; what follows is simply that A is in C. And if it is further granted that A is the quod quid of something and is predicated universally of B, it does not yet follow that A is the quod q uid of C: for it is plain that this, i.e., the quod quid of animal is universally predicated of this which is man’s quod quid. For just as it is true that animal is universally predicated of man, so it is true that the definition of animal is universally predicated of the definition of man; but that does not mean that they are entirely one and the same.
Sic igitur patet quod si aliquis non sic accipiat terminos, ut primum sit omnino unum et idem medio, et medium ultimo, non poterit syllogizari quod a, quod est primum, sit quod quid est ipsi c, quod est ultimum, et essentia eius. Si vero accipiantur termini modo praedicto, sequitur quod priusquam concludatur, accipiatur in praemissis quod quid est ipsius c, scilicet ipsum b. Ex quo sequitur quod non sit demonstratio, sed petitio vel acceptio principii.	And so it is clear that unless one takes the terms in such a way that the first is entirely one and the same with the middle, and the middle with the last, it will not be possible to syllogize that A, which is the first, is the quod quid of C—which is the last—and its essence. But if the terms are taken in that way, it follows that prior to its being concluded, the quod quid of C, namely, B, was assumed in the premises. From this it follows that there is not a demonstration but a begging or assuming of the question.

Lecture 4 Whether quod quid can be demonstrated by the method of division

Latin	English
	Lecture 4 (91b12-92a6) WHETHER QUOD QUID CAN BE DEMONSTRATED BY THE METHOD OF DIVISION
lib. 2 l. 4 n. 1 Postquam philosophus ostendit quod non potest demonstrari quod quid est per terminos convertibiles, hic ostendit quod non potest demonstrari per viam divisionis. Et circa hoc duo facit: primo, ostendit propositum; secundo, excludit quamdam solutionem; ibi: contingit autem solvere et cetera. Circa primum duo facit: primo, ostendit propositum per rationem communem omnibus quae syllogizari possunt; secundo, ostendit propositum quantum ad ea quae sunt propria ei quod quid est: ibi: quid enim prohibet et cetera.	After showing that quod quid cannot be demonstrated with convertible terms, the Philosopher now shows that it cannot be demonstrated by the method of division. And in regard to this he does two things. First, he shows what he proposes. Secondly, he excludes a certain solution (91b28). Concerning the first he does two things. First, he shows what he proposes by using a reason common to all things which are syllogized. Secondly, he shows it with reasons proper to that which is quod quid (91a45).
lib. 2 l. 4 n. 2 Dicit ergo primo quod, sicut non potest demonstrari quod quid est per terminos convertibiles, ita etiam non potest demonstrari per viam divisionis: per quam etiam nihil syllogistice probatur, sicut dictum est in resolutione circa figuras, idest in I priorum analyticorum. Sicut enim in posterioribus analyticis docetur resolutio usque ad principia prima, ita etiam in prioribus analyticis fit resolutio ad prima quaedam simplicia pertinentia ad dispositionem syllogismi in modo et figura.	He says therefore first (91b12) that just as the quod quid cannot be demonstrated by convertible terms, so neither by the method of division through which, as a matter of fact, nothing is proved syllogistically, as was established in Resolutions Touching Figures, i.e., in Prior Analytics I. For just as in the Posterior Analytics resolution to first principles is taught, so in the Prior Analytics resolution is made to certain first simple items which pertain to the arrangement of the syllogism in mood and figure.
lib. 2 l. 4 n. 3 Quod autem per viam divisionis non possit aliquid syllogizari probat per hoc, quod in via divisionis non ex necessitate sequitur conclusio, existentibus praemissis (quod requiritur ad rationem syllogismi): sed ita se habet in via divisionis, sicut et in via inductionis. Ille enim qui inducit per singularia ad universale, non demonstrat neque syllogizat ex necessitate. Cum enim aliquid syllogistice probatur, non est necessarium ulterius quod vel syllogizans interroget de conclusione, nec quod respondens det ei conclusionem: sed necesse est quod conclusio sit vera, praemissis existentibus veris. Hoc autem non accidit in via divisionis, sicut manifestat per exempla. Proceditur enim via divisionis cum, accepto aliquo communi quod per multa dividitur, remoto uno, concluditur alterum. Puta si entium aliud est animal et aliud inanimatum, habito quod homo non sit inanimatum, concluditur quod sit animal: sed ista conclusio non sequitur, nisi respondens det quod homo vel sit animal vel inanimatum.	That something cannot be syllogized by the method of division he proves from the fact that in this method, given the premises, the conclusion does not follow of necessity, which it should, considering the nature of a syllogism. Rather, the same thing happens in the method of division as happens in the method of induction. For one who induces through singulars to the universal does not demonstrate or syllogize from necessity. For when something is proved syllogistically, it is not necessary to make further inquiry concerning the conclusion or to ask that the conclusion be conceded; what is necessary is that the conclusion be true, if the premises laid down are true. But, as he shows with certain examples, this does not happen in the method of division. For the method of division consists in assuming something common which is divided into at least two members, so that, one being removed, the other is concluded. For example, if beings are so divided that on the one hand is animal and on the other lifeless things, then having established that man is not a lifeless thing, it is concluded that he is animal. But this conclusion does not follow, unless the hearer grants that man is either an animal or a lifeless thing.
lib. 2 l. 4 n. 4 Et est attendendum quod satis convenienter comparavit divisionem inductioni. Utrobique enim oportet supponere quod accepta sint omnia quae continentur sub aliquo communi: alioquin nec inducens poterit ex singularibus acceptis concludere universale, nec dividens ex remotione quarumdam partium poterit concludere aliam. Patet igitur quod inducens, facta inductione quod Socrates currat et Plato et Cicero, non potest ex necessitate concludere quod omnis homo currat, nisi detur sibi a respondente quod nihil aliud contineatur sub homine quam ista quae inducta sunt. Similiter etiam nec dividens, si probaverit quod hoc coloratum non sit album nec pallidum, non potest ex necessitate concludere quod sit nigrum, nisi detur sibi a respondente quod nihil aliud contineatur sub colorato nisi ea quae assumpta sunt in divisione. Et quia investigantibus quid est homo, oportet accipere non solum genus, quod est animal, sed etiam differentiam; ulterius in suo exemplo procedit quod, si omne animal aut gressibile est aut aquaticum, et accipiat quod homo, quia non est aquaticum animal, sit totum hoc quod est animal gressibile, non ex necessitate sequitur ex dictis; sed oportet quod hoc etiam supponat datum sibi a respondente, scilicet quod animal sufficienter dividatur per gressibile et aquaticum. Et quia quandoque per plures divisiones proceditur ad accipiendum quod quid est alicuius rei, ideo, praemissis duabus divisionibus in suo exemplo, subdit quod nihil differt quod sic procedatur in multis aut in paucis. Eadem enim est ratio in omnibus. Et sic ulterius concludit quod procedentes per viam divisionis, etiam circa ea quae contingit syllogizari, non utuntur probatione syllogistica.	It might be remarked here that he quite fittingly compared division to induction. For in both cases one is required to suppose that he has listed all the things contained under some general heading; otherwise, the person inducing could not conclude a universal from the singulars he assumed, nor could the person dividing conclude to one member just because the others have been eliminated. Thus it is obvious that one cannot in virtue of the fact that Socrates and Plato and Cicero run, induce of necessity the conclusion that every man runs, unless his audience concedes that nothing more is contained under man than the ones listed. In like manner, one who divides cannot, in virtue of having proved that this colored object is neither white nor grey, conclude of necessity that it is black, unless his audience grants him that nothing else is contained under colored object than the things mentioned in the division. And because a person investigating what man is must assume not only the genus which is animal but also the difference, he goes on to say in his example that if every animal is either of the land or of the water and it is established that because man is not a water animal, he is this whole which is land animal, that statement does not follow of necessity from the premises: rather it is further required that he suppose his audience to have granted him something, namely, that animal is sufficiently divided into those of the land and those of the water. And because in some cases several divisions are used in obtaining the quod quid of a thing, the fore, after laying down two divisions in his example, he adds that it makes no difference whether few or many are used. For the formality is the same in all. And thus he concludes once more that those who proceed by the method of division, even in matters that could be syllogized, do not use a syllogized proof.
lib. 2 l. 4 n. 5 Deinde cum dicit: quid enim prohibet hoc verum etc., inducit duas rationes proprias ei quod quid est. Quarum prima est, quia non omne quod vere praedicatur de aliquo, praedicatur in eo quod quid est, nec significat essentiam eius. Si ergo detur quod per viam divisionis sufficienter probetur quod totum hoc, scilicet animal gressibile, vere praedicetur de homine; non tamen propter hoc erit probatum quod praedicetur de eo in eo quod quid est, vel ostendat quod quid erat esse, idest quod demonstrat essentiam rei.	Then (91b25) he induces two reasons proper to the quod quid. The first of these is that not everything which is truly predicated of something is predicated in quod quid or signifies its essence. Therefore, even if it be conceded that one has sufficiently proved by the method of division that this whole, namely, land animal, is truly predicated of man, it does not on that account follow that it is predicated of it in quod quid or that it shows the quod quid erat esse, i.e, that it demonstrates the essence of the thing.
lib. 2 l. 4 n. 6 Secundam rationem ponit ibi: amplius quid prohibet aut apponere et cetera. Essentia enim cuiuslibet rei declaratur per aliqua certa, quibus nec addere oportet nec subtrahi. Nihil autem prohibet quin ille qui procedit per viam divisionis, aut apponat aliquid supra ea quae sufficiunt ad ostendendum quod quid est, aut auferat aliquid eorum quae ad hoc sunt necessaria, aut etiam quod supergrediatur vel excellat essentiam rei, utpote si sit communius quam ipsa res; quod fit dum subtrahuntur differentiae ultimae, quibus ea quae sunt communia contrahuntur. Unde per divisionem non probatur sufficienter quod quid est. Et hoc est quod concludit, quod in via divisionis praetermittuntur praedictae conditiones; ut scilicet id quod concluditur, praedicetur in eo quod quid est, et quod nec excedat nec excedatur.	Then (91b26) he gives the second reason. For the essence of a thing is declared through certain definite items which may neither be added to or subtracted from. But there is nothing to hinder one who proceeds by the method of division from adding something over and above the items which suffice for showing the quod quid, or from subtracting some of the things which are necessary for this, or from going beyond and exceeding the essence of the thing, as when it is more common than the thing itself—which happens when the ultimate differences which contract common things are removed. Hence the quod quid is not sufficiently proved by division. And this is what he concludes, namely, that in the method of division the above-mentioned conditions are not satisfied, i.e., the conditions that what is concluded be predicated in quod quid and that it neither exceed nor be exceeded.
lib. 2 l. 4 n. 7 Deinde cum dicit: contingit autem solvere in accipiendo etc., excludit quamdam solutionem. Et primo, proponit eam; secundo, excludit ipsam; ibi: sed syllogismus tamen et cetera. Dicit ergo primo quod contingit solvere ea quae obiecta sunt, ex eo quod aliquis dicat quod dividendo accipiat omnia quae praedicantur in eo quod quid est; et ita per consequentiam ad divisionem faciat id quod primo intenditur, ut scilicet constituat definitionem significantem quod quid est, et nihil relinquat eorum quae requiruntur ad definiendum. Et si haec duo faciat, scilicet quod omnia, quae accipit per divisionem, praedicentur in eo quod quid, et omnia huiusmodi cadant in divisione, ita quod nihil desit, necessarium est quod id quod est inventum sit quod quid est. Et huiusmodi necessitatis ratio est quia, acceptis omnibus quae praedicantur in eo quod quid, nullo derelicto, iam id quod inventum est, oportet esse quoddam individuum, idest individuam rationem talis rei; ita scilicet quod non indigeat ulteriori divisione ad hoc quod approprietur huic rei.	Then (91b28) he excludes a certain solution. First, he proposes it. Secondly, he excludes it (91b33). He says therefore first (91b28) that one might solve our objections by saying that when a division is made, one could be taking all the things that are predicated in quod quid, so that as a consequence of the division he accomplishes what was primarily intended, namely, that he obtains a definition signifying the quod quid and leaves out nothing which is required for defining. And if he does these two things, namely, if all the items he assumes in the division are predicated in quod quid and all such things are included in the division so that nothing is left out, then it is necessary that what is obtained be the quod quid. And the reason for this necessity is that in taking everything which is predicated in quod quid and leaving nothing out, that which is found must be something individual, i.e., the individual notion of such a thing, so that no further division is required for it to be appropriate to this thing.
lib. 2 l. 4 n. 8 Deinde cum dicit: sed syllogismus tamen non inest etc., excludit praedictam solutionem: et dicit quod quamvis necesse sit, praedictis existentibus, aliquid individuum fieri, sicut expositum est, tamen praedicta via non est syllogistica; quamvis cognoscere faciat quod quid est per alium modum. Et hoc non est inconveniens, scilicet quod aliquid alio modo manifestetur quam per syllogismum. Ille enim qui utitur inductione, non probat syllogistice, sed tamen aliquid manifestat.	Then (91b33) he excludes this solution, saying that even though under the aforesaid conditions something individual is necessarily obtained, as explained above, the method is nevertheless not syllogistic; although it might make one know the quod quid in some other way. And this is not unbecoming, namely, that something be manifested in a way other than by a syllogism: for one who uses induction does not prove anything syllogistically, but yet he does manifest something.
Quod autem ille qui per divisionem ad definitionem pervenit, non faciat syllogismum, ostendit per quoddam simile. Si enim inducatur conclusio ex maiori propositione, subtracta media, et concludens dicat quod hoc necesse est sequi ex praemissis, poterit interrogare respondens, propter quid sit necessarium: quod non accidit in syllogistica probatione. Unde talis modus argumentandi non est syllogisticus. Ita etiam in terminis divisivis non fit syllogismus, quia semper restat interrogatio propter quid. Puta si aliquis volens notificare quid est homo, accipiat per viam divisionis quod homo est animal mortale bipes, vel habens pedes, sine pennis; ad quamlibet appositionem praedictorum poterit convenienter quaeri propter quid sit necesse. Ille enim qui ad manifestandum quod quid est conatur, non solum dicet, sed etiam probabit per divisionem, secundum quod ipse opinatur, quod omne quod est sit mortale aut immortale. Et quamvis detur quod per hanc divisionem possit demonstrare propositum, tamen non est necesse quod ratio sic conclusa sit definitio; quia forte ea ex quibus constat ratio talis, non praedicantur in eo quod quid est, vel excedunt substantiam definiti. Sed etsi contingat quod talis ratio sit definitio, non tamen per syllogismum probatur quod definitio sit, ut ex supra dictis patet.	That one who reaches a definition by way of division does not achieve a syllogism he shows by something similar. For if a conclusion is induced from a major proposition, the second proposition being omitted, and the person concluding declares that this must follow from the premises, the hearer could ask why it is necessary—which is something that does not happen in a syllogistic proof. Hence such a method of arguing is not syllogistic. Similarly, in terms of division no syllogism is achieved, because t lie question why always remains. Thus, if someone wishing to disclose what man is were to assert by the method of division that man is a two-footed mortal animal, or one that has two feet but no wings, then as h adds one item to another in his division, he could be asked in regard to each one, why is it necessary. For one who sets out to manifest a quod quid by division will not only assert but also prove—in keeping with what he thinks—that everything which exists is mortal or immortal. And although it be granted that through this division he might be demonstrating his proposition, nevertheless it is not necessary that the notion’ so concluded be a definition; for perhaps the items out of which such a notion is formed are not predicated in quod quid or exceed the substance of the thing defined. But even though such a notion might happen to be a definition, it is nevertheless not proved by the syllogism to be a definition, as is clear from what has been established above.

Lecture 5 Whether a quod quid can be demonstrated by taking that which is required for a quod quid

Latin	English
	Lecture 5 (92a6-b3) WHETHER A QUOD QUID CAN BE DEMONSTRATED BY TAKING THAT WHICH IS REQUIRED FOR A QUOD QUID
lib. 2 l. 5 n. 1 Postquam philosophus ostendit quod non potest demonstrari quod quid est, nec per convertibiles terminos, nec per viam divisionis, hic ostendit ulterius quod non potest quod quid est demonstrari, accipiendo id quod requiritur ad quod quid est. Et circa hoc duo facit: primo, ostendit propositum; secundo, concludit ex omnibus praemissis quod nullo modo quod quid est demonstrari possit; ibi: qualiter igitur definiens et cetera. Circa primum duo facit: primo, inducit rationes proprias ad propositum; secundo, inducit quamdam rationem communem ad id quod nunc dicitur, et ad id quod supra dictum est; ibi: ad utrosque autem et cetera. Circa primum duo facit: primo, ostendit quod non potest demonstrari quod quid est per hoc quod accipiatur id quod pertinet ad rationem eius quod quid est; secundo, ostendit quod non potest demonstrari quod quid est huius rei, ex hoc quod accipitur quod quid est alterius rei; ibi: ex suppositione autem et cetera. Circa primum duo facit: primo, movet quaestionem; secundo, argumentatur ad propositum; ibi: aut iterum accipit et cetera.	After showing that the quod quid cannot be demonstrated either by convertible terms or by the method of division, the Philosopher here shows that it cannot be demonstrated by taking that which is required for a quod quid. In regard to this he does two things. First, he shows what he proposes. Secondly, he concludes from all of the foregoing that there is no way in which quod quid maybe demonstrated (92a34). Concerning the first he does two things. First, he employs reasons proper to what he proposes. Secondly, he employs a reason common to what is now being said and to what was said above (92a28). Concerning the first he does two things. First, he shows that the quod quid cannot be demonstrated by taking that which pertains to the notion of its quod quid. Secondly, he shows that the quod quid of this thing cannot be demonstrated by taking the quod quid of some other thing (9240). In regard to the first he does two things. First, he raises the question. Secondly, he argues for his proposal (92a9).
lib. 2 l. 5 n. 2 Quaerit ergo primo, utrum contingat demonstrare quid sit aliquid secundum suam substantiam, ex tali suppositione, per quam accipiatur quod quid erat esse alicuius rei, ex illis conditionibus quae sunt propriae ei quod quid est. Puta si aliquis probet quod animal gressibile bipes sit quod quid est hominis, accipiens pro medio quod haec ratio convertitur cum homine, et constat ex genere et differentia. Haec autem sola requiruntur ad hoc quod quid est, et totum hoc quod dictum est, est proprium ei quod quid est, quia est esse illi, scilicet ei quod est quod quid est: quasi dicat quod hoc quod est esse rationem convertibilem, ex genere et differentiis constantem, est omnino idem ei quod quid est.	He asks therefore first (92a6) whether one might demonstrate what something is according to its substance by supposing that the quod quid of a thing can be obtained if one satisfies the conditions which are proper to the quod quid: for example, if one were to prove that two-footed land animal is the quod quid of man, having taken as middle the fact that this notion is converted with man and is composed of genus and difference; which are the only conditions required for a quod quid. Furthermore, this whole, which has been stated, is proper to the quod quid because it is the being or reality of it, i.e., of that which is quod quid. It is as though he were saying that being a convertible notion composed of a genus and difference is exactly the same as being the quod quid.
lib. 2 l. 5 n. 3 Deinde cum dicit: an iterum accepit etc., obiicit ad praedictam quaestionem duabus rationibus, ostendens quod non potest quod quid est praedicto modo demonstrari. Quarum prima est, quia sicut praemissi modi demonstrandi deficiunt in hoc quod accipiunt id quod quaeritur, ita est in proposito. Accipitur enim et in hoc modo probationis quod quid erat esse; puta dum accipitur quod omnis ratio convertibilis, constans ex genere et differentiis, significat quod quid est: et ita inconveniens est probatio. Necesse est enim id ad quod demonstratio inducitur, non supponere quasi medium; sed potius per aliud medium demonstrare.	Then (92a9) he lodges two objections against the above question, showing that the quod quid cannot be demonstrated in the way it suggests. The first of these is that just as the previously mentioned ways of demonstrating failed because they assumed the very thing in question, so too in the present instance. For it, too, assumes the quod quid erat esse, as for example when it is assumed that every convertible notion composed of genus and difference signifies the quod quid est; consequently, the proof is not acceptable. For one must never take as middle the very thing the demonstration is intended to prove; rather it is necessary to demonstrate it through some other middle.
lib. 2 l. 5 n. 4 Secundam rationem ponit ibi: amplius sicut neque in syllogismo etc.; quae sumitur ex similitudine syllogismi. Cum enim aliquis syllogizat, non oportet quod accipiat definitionem syllogismi ad syllogizandum; quia ea ex quibus procedit syllogismus, hoc modo se habent, quod semper quodlibet eorum est aut tota propositio, idest universalis seu maior, aut est pars, idest particularis seu minor, quae sumitur sub maiori. Et ita definitio syllogismi non est aliquid eorum ex quibus procedit syllogismus. Et similiter si aliquis velit syllogizare quod quid erat esse alicuius rei, non oportet quod accipiat quid sit quod quid erat esse: sed oportet hoc seorsum haberi in mente, praeter ea quae ponuntur in definitione vel syllogismo. Huiusmodi enim rationes syllogismi et definitionis se habent in definiendo et syllogizando, sicut regulae artis, ad quas debet aspicere artifex in operando. Artifex autem qui facit cultellum, non facit operando regulam, secundum quam operatur: sed secundum regulam, quam habet in mente, examinat an cultellus bene sit factus. Ita etiam ille qui syllogizat non accipit rationem syllogismi in syllogizando: sed per rationem syllogismi examinat syllogismum factum an sit bonus.	Then (92a11) he gives the second reason, which is based on a likeness to a syllogism. For when a person syllogizes, he is not required to use the definition of syllogism in order to syllogize; because the items from which a syllogism proceeds are such that each item is either a whole proposition, i.e., a universal or major proposition, or a part, i.e., a particular or minor proposition subsumed under the major one. Consequently, the definition of a syllogism is not one of the things from which a syllogism proceeds. In like manner if someone wishes to syllogize the quod quid erat esse of something, he is not required to mention what a quod quid erat esse is; but he must have this in reserve in his mind over and above the items which are put in the definition or in the syllogism. For these notions of a syllogism and of a definition function in defining and syllogizing as rules of art which an artisan must respect in his works. Now an artisan who makes a knife does not do so by establishing the rules according to which he works, but in the light of the rules he has in his mind he examines whether the knife was made well. So, too, a person who syllogizes does not mention the notion of a syllogism as he syllogizes, but in view of the notion of a syllogism he examines the syllogism he made, in order to see whether it is good.
Unde si aliquis dubitet, syllogismo facto, an sit syllogizatum vel non, poterit syllogizans obviare, ostendendo quod sit syllogizatum, ostendendo quod syllogismus sit tale aliquid. Similiter etiam ei qui intendit syllogizare quod quid erat esse, convenit ut habeat seorsum in mente rationem eius quod quid erat esse: ut si aliquis dicat quod non est syllogizatum quod quid erat esse, ipse dicat quod immo, quia tale aliquid ponitur quod quid erat esse. Sic ergo patet quod syllogizans quod quid erat esse, neque debet sumere quid est syllogismus, neque quid est quod quid erat esse.	Hence if a person should wonder, once a syllogism has been formed, whether it syllogized or not, the one who formed the syllogism can settle this doubt by showing that it does syllogize, on the ground that a syllogism is such and such a thing. So, too, a person who intends to syllogize the quod quid erat esse should have reserved in his mind the notion of what a quod quid erat esse is, so that if someone should say that a quod quid erat esse has not been syllogized, he can answer that it has, because such and such is put down as the quod quid erat esse. Thus, therefore, it is clear that a person who syllogizes a quod quid erat esse should not state what a syllogism is or what a quod quid erat esse is.
lib. 2 l. 5 n. 5 Deinde cum dicit: et si ex suppositione etc., ostendit quod non potest demonstrari quod quid est unius rei ex quod quid est alterius rei. Et circa hoc duo facit: primo, proponit quod intendit; secundo, probat propositum; ibi: etenim hic accipiens et cetera. Dicit ergo primo quod etiam non probatur quod quid est, si aliquis velit hoc probare ex suppositione quod quid est alterius rei. Puta si aliquis sic procedat accipiens quod idem sit esse divisibili et malo, idest quod divisio sit quod quid est mali, et ulterius argumentetur sic: in omnibus quae habent contrarium, contrarii est contrarium quod quid est; sed bono est contrarium malum, et indivisibile est contrarium divisibili; sequitur ergo quod indivisibile sit quod quid est ipsius boni. Et sumuntur ista exempla secundum opinionem Platonis, qui posuit quod eadem est ratio unius et boni. Videmus enim quod unumquodque appetit unitatem sicut proprium bonum. Unum autem est idem quod indivisibile; et sic per oppositum sequitur quod malum sit idem quod divisibile. Unumquodque enim refugit divisionem sui, quia per hoc tendit ad diminutum et imperfectum.	The (92a20) he shows that the quod quid of one thing cannot be demonstrated from the quod quid of another thing. Concerning this he does two things. First, he proposes what he intends. Secondly, he proves what he proposes (92a23). He says therefore first (92a20) that the quod quid is not proved, if someone wished to prove it by supposing the quod quid of some other thin ; for example, if someone were to proceed in such a way as to assume that the being or reality of divisible and of evil is the same, i.e., that division is the quod quid of evil, and then argued in the following manner: “In all things which have a contrary the quod quid of one contrary is a contrary; but the contrary of good is evil, and of divisible the contrary is indivisible: therefore, it follows that indivisible is the quod quid of the good.” And these examples are taken according to Plato’s opinion that the notion of the one and of the good are the same. For we notice that everything seeks unity as its own good. But one is the same as indivisible; and so in virtue of the opposition it follows that evil is the same as divisible. For everything shuns division of the self, because through division it tends to what is shattered and imperfect.
lib. 2 l. 5 n. 6 Deinde cum dicit: etenim hic accipiens etc., probat propositum, scilicet quod non possit demonstrari quod quid est; et hoc duabus rationibus. Quarum prima est, quia etiam in hoc modo probationis demonstrat aliquis accipiendo quod quid erat esse, et ita accipit quod oportet probare.	Then (92a23) he proves what he has proposed, namely, that the quod quid cannot be demonstrated: and this by giving two reasons. The first of these is that even according to this method one demonstrates by assuming the quod quid erat esse, and thus he assumes what he should have proved.
lib. 2 l. 5 n. 7 Secundam rationem ponit ibi: accipit autem ad demonstrandum etc.; et dicit quod non solum est inconveniens quod accipiatur quod quid erat esse ad demonstrandum, sed et alterum inconveniens fit quod accipitur quod quid erat esse ad demonstrandum quod quid erat esse: quia etiam in demonstrationibus in quibus probatur hoc de hoc, puta passio de subiecto, accipitur pro medio quod quid erat esse, non tamen quod quid erat esse quod accipitur, est ipsummet quod debet concludi, vel aliquid quod habeat eamdem rationem et convertatur. Eamdem autem rationem habet quod bonum sit indivisibile, et malum divisibile; et haec duo convertuntur, quia posito uno ponitur alterum, et e converso.	Then (92a24) he gives the second reason, saying that not only is it improper to take the quod quid erat esse when demonstrating, but this impropriety is compounded when one takes a quod quid erat esse to demonstrate a quod quid erat esse: because even in demonstrations in which this is proved of this, say a proper attribute of a subject, a quod quid erat esse is taken as middle; nevertheless the one so taken is not the very thing which was to be concluded or something which has the same notion and is converted. But good and indivisible, and evil and divisible, have the same notion; and each pair is converted, because one being posited, the other is posited, and vice versa.
lib. 2 l. 5 n. 8 Deinde cum dicit: ad utrosque autem et secundum divisionem etc., inducit rationem communem contra eum qui demonstrat ex suppositione et divisione; et dicit quod eadem oppositio habet locum contra utrosque, scilicet contra eum qui vult demonstrare quod quid est per divisionem, et contra eum qui utitur suppositione quod quid est in syllogismo. Manifestum est enim quod definitio significat unum aliquid: unde ea quae ponuntur in definitione, ad significandum unitatem, debent poni absque copula; puta ut dicatur quod homo est animal gressibile bipes, non autem debet dici quod homo sit animal et bipes. Unde si aliquis vult probare quod quid est, oportet quod probet ex his, quae assumuntur, fieri unum. Sed non est necessarium, secundum praedictas vias divisionis et suppositionis, quod ex his quae accipiuntur ad definiendum, fiat unum praedicatum: sed poterit esse quod sint multa, puta si dicatur quod homo est grammaticus et musicus. Videtur igitur quod secundum vias praedictas, non probetur quod quid est.	Then (92a28) he presents a common reason against anyone who demonstrates from supposition and division. And he says that the same opposition is directed against both, namely, against one who tries to demonstrate the quod quid by division and against one who proceeds by laying down the quod quid in the syllogism. For clearly a definition signifies something which is one: hence to signify this oneness the items laid down in the definition should be arranged without a conjunction; thus one should say that man is a two-footed land animal, but not that man is an animal and two-footed. Hence if anyone desires to prove the quod quid, he must prove that one thing is formed from the things assumed. But it is not required, according to the above-cited methods of division and supposition, that one predicate be formed from these items which are taken for defining: since there might be several, for example, if one should state that man is grammatical and musical. It seems therefore that according to the ways mentioned above, the quod quid is not proved.
lib. 2 l. 5 n. 9 Deinde cum dicit: qualiter igitur definiens etc., concludit ex praemissis quod nullo modo potest probari quod quid est; et dicit: si igitur neque per terminos convertibiles, neque per divisionem, neque per suppositionem demonstratur quod quid est, quomodo igitur definiens poterit demonstrare substantiam rei vel quod quid est? Iam enim ex praemissis patet quod non probat, sicut manifestum faciens ex his quae sunt per se nota, quod necesse sit alterum aliquid sequi per ea quae dicta sunt, quod requiritur ad demonstrationem.	Then (92a34) he concludes from the foregoing that there is no way to prove the quod quid, saying: if then the quod quid cannot be proved either by convertible terms or division or opposition, how will the definer be able to demonstrate the substance of a thing or the quod quid? For it is now clear from the foregoing that he does not prove it according to the method whereby, in virtue of items that are per se known, one manifests that something else must follow through things which are said-which is required for a demonstration.
Relinquitur autem praeter tres modos quartus modus, qui est per inductionem. Sed nec contingit probare quod quid est per singularia manifesta, ita scilicet quod aliquid praedicetur de omnibus, et non sit aliquid eorum quod aliter se habeat: quia sic inducendo non demonstrabit quod quid est, sed demonstrabit aliquid esse vel non esse, puta quod omnis homo est animal, vel nullus homo est lapis.	However, besides these three modes there is a fourth, namely, through induction. But it turns out that the quod quid cannot be proved by manifest singulars, namely, in such a way that something is predicated of all and is not anything that might be otherwise: because one who thus proceeds by induction will not demonstrate the quod quid but will demonstrate that something is or is not; for example, that every man is an animal, or that no animal is a stone.
Nullus autem alius modus relinquitur ad demonstrandum quod quid est: nisi forte modus demonstrationis qui est ad sensum, sicut cum aliquid demonstratur digito. Manifestum est autem quod hic modus non potest competere in proposito: quia quod quid est non est obiectum sensus, sed intellectus, ut dicitur in III de anima. Relinquitur ergo quod nullo modo possit demonstrari quod quid est.	But no other method is available for demonstrating the quod quid, save perhaps the method of demonstrating something to the senses, as when something is pointed out with the finger. But it is obvious that this method cannot be invoked in the present instance, because the quod quid is not an object of sense but of intellect, as it is stated in On the Soul III. It remains, therefore, that there is no way in which the quod quid can be demonstrated.

Lecture 6 Whether quod quid can be shown by demonstration or definition

Latin	English
	Lecture 6 (92b3-39) WHETHER QUOD QUID CAN BE SHOWN BY DEMONSTRATION OR DEFINITION
lib. 2 l. 6 n. 1 Postquam philosophus ostendit quod non contingit demonstrare quod quid est, inducendo per singulos modos quibus aliquid demonstrari potest, hic ostendit propositum per rationes communes. Et circa hoc tria facit: primo, praemittit quoddam quod est necessarium ad propositum ostendendum; secundo, ostendit propositum; ibi: at vero si demonstrabit quod quid est etc.; tertio, epilogat quae dicta sunt; ibi: ex his igitur neque definitio et cetera.	After considering each of the ways in which something might be demonstrated and showing that none can demonstrate the quod quid, the Philosopher now shows what he proposes through common reasons. Concerning this he does three things. First, he lays down something which is necessary for proving what he proposes. Secondly, he shows what he proposes (957). Thirdly, he sums up what has been stated (97b35).
lib. 2 l. 6 n. 2 Dicit ergo primo quod non videtur esse possibilis aliquis modus, quo aliquis demonstret quod quid est esse hominis; et hoc ideo, quia necesse est quod quicunque scit quod quid est esse hominis, vel cuiuscunque alterius rei, quod sciat rem illam esse. Quia enim non entis non est aliqua quidditas vel essentia, de eo quod non est, nullus potest scire quod quid est; sed potest scire significationem nominis, vel rationem ex pluribus nominibus compositam: sicut potest aliquis scire quid significat hoc nomen Tragelaphus vel Hircocervus, quod idem est, quia significat quoddam animal compositum ex hirco et cervo; sed impossibile est scire quod quid est Hircocervi, quia nihil est tale in rerum natura.	He says therefore first (92b3) that there does not seem to be any possible way for a person to demonstrate that some quod quid is man: and this because whoever knows a quod quid to be of man or of any other thing is required to know that the thing exists. For since there is no quiddity or essence of a non-being, it is impossible to know the quod quid of something which is not; but one might know the meaning of the name or have a notion composed of several names. Thus a person is capable of knowing the ‘ meaning of the word tragelaphus or goat-stag, because it signifies an animal composed of goat and stag, but it is impossible to know the quod quid of a goat-stag, because there is no such thing given in nature.
lib. 2 l. 6 n. 3 Deinde cum dicit: at vero si demonstrabit quid est etc., ex eo quod praemissum est, procedit ad propositum ostendendum. Et circa hoc duo facit: primo, ostendit quod non potest ostendi quod quid est demonstratione; secundo, quod non potest ostendi definitione; ibi: si ergo et definiens demonstrat et cetera. Circa primum ponit tres rationes; quarum prima talis est. Sicut definitio inducitur ad manifestandum aliquid unum, in quantum scilicet ex partibus definitionis fit unum per se, non per accidens, ita etiam oportet quod demonstratio, quae utitur definitione tanquam medio, unum aliquid demonstret: oportet enim conclusionem esse medio proportionatam. Et ita patet quod per unam et eamdem demonstrationem non possunt diversa demonstrari. Sed aliud est quod quid est homo, et esse hominem: in solo enim primo essendi principio, quod est essentialiter ens, ipsum esse et quidditas eius est unum et idem; in omnibus autem aliis, quae sunt entia per participationem, oportet quod sit aliud esse et quidditas entis. Non est ergo possibile quod eadem demonstratione demonstret aliquis quid est et quia est.	Then (92b7) from what has been established he goes on to prove what he proposed. In regard to this he does two things. First, he shows that the quod quid cannot be shown by demonstration. Secondly, that it cannot be shown by definition (9526). In regard to the first he presents three reasons, the first of which (92b7) is the following: just as a definition is brought forward to manifest something which is one in the sense that from the parts of the definition something is formed which is one per se and not one per accidens, so a demonstration which employs a definition as its middle must demonstrate something which is one; for the conclusion must be proportionate to the middle. Consequently, it is clear that one cannot in virtue of one and the same definition demonstrate things that are diverse. But the quod quid of man is one thing and his being or existence is another—for it is only in the First Principle of being, Who is being essentially, that to be and quiddity are one and the same; in all other things, which are beings by participation, the to be has to be other than the quiddity. Therefore, it is not possible to demonstrate both the quid and the quia with the same demonstration.
lib. 2 l. 6 n. 4 Secundam rationem ponit ibi: postea et per demonstrationem etc.; quae talis est. Secundum commune sapientum dictum, necessarium est quod omne, idest totum quod per demonstrationem demonstratur, sit ipsum quia est, nisi forte aliquis dicat quod hoc ipsum quia est sit substantia alicuius rei. Hoc autem est impossibile. Hoc enim ipsum quod est esse, non est substantia vel essentia alicuius rei in genere existentis. Alioquin oporteret quod hoc quod dico ens esset genus, quia genus est quod praedicatur de aliquo in eo quod quid. Ens autem non est genus, ut probatur in III Metaph. Et propter hoc etiam Deus, qui est suum esse, non est in genere.	Then (92b11) he presents the second reason and it is this: According to a common opinion of wise men, it is necessary that all i.e., the whole demonstrated by a demonstration, be the quia est, unless perchance someone would want to say that the quia est itself is the substance of a thing. However, this is impossible. For the to be is not the substance or essence of anything existing in a genus; otherwise it would be required that being be a genus, because a genus is something predicated in quod quia. But, as it is proved in Metaphysics III, being is not a genus. For this reason God Who is His own essence is not in a genus.
Si autem quia est esset substantia alicuius rei, simul cum aliquis ostenderet quia est, ostenderet quid est, et ita non totum quod demonstratio demonstrat, esset quia est. Illud autem est falsum. Ergo patet quod demonstratio solum demonstrat quia est. Demonstrat enim enunciationem aliquam, quae significat esse vel non esse.	Furthermore, if the quia est were the substance of any thing, then in the same breath that one shows the quia est he would be showing the quid est; consequently, the whole which a demonstrator manifests would not be the quia est. But this is false. Therefore, it is clear that demonstration manifests only the quia est, for it demonstrates some enunciation which signifies that something is or is not.
Et hoc etiam apparet in processu scientiarum. Geometra enim accipit quid significat hoc nomen triangulus, et demonstrat quod sit, puta cum demonstrat super lineam rectam datam triangulum aequilaterum constituere. Si igitur aliquis demonstraret solum quid est triangulus, praeter morem demonstrationum quibus utuntur scientiae, non demonstraret hoc totum quod est triangulum esse, sed demonstraret solum hoc quod dico triangulum. Sicut enim propter hoc quod esse non est substantia rei, ille qui demonstrat esse, hoc solum demonstrat; ita si aliquis demonstraret quid est, hoc solum demonstraret. Sequeretur igitur quod aliquis sciens per definitionem quid est, nesciret an est, quod est impossibile, ut ex praedictis patet.	This is apparent also in the way a science proceeds. For geometry assumes what the name triangle signifies, and demonstrates quod sit, as when it demonstrates that an equilateral triangle has been formed on a given straight line. Therefore, if one demonstrated merely what a triangle is apart from the method of demonstrating which the sciences employ, he would not be demonstrating this whole which is that a triangle exists, but only what I call triangle. For just as, owing to the fact that to be is not the substance of a thing, one who demonstrates to be demonstrates that and nothing more, so if someone demonstrates the quid est, that is all he demonstrates. It would follow, therefore, that someone who knew the quid est in virtue of a definition would not know an est—which is impossible in view of what has been established above.
lib. 2 l. 6 n. 5 Tertiam rationem ponit ibi: manifestum autem est secundum nunc etc.; quae per exempla consuetarum definitionum manifestat idem, quod in praecedenti ratione est conclusum, scilicet quod monstrans quid est non monstrat quia est. Unde dicit manifestum esse non solum secundum praedicta, sed etiam secundum modos terminorum, idest definitionum, quae nunc sunt in usu, quod illi qui definiunt, non manifestant quia est. Puta qui definit circulum, dicens quod est aliquid ex cuius medio lineae ad circumferentiam ductae sunt aequales, adhuc restat quaestio propter quid oporteat poni esse id quod definitur; puta propter quid oporteat poni quod sit circulus, qui praedicto modo definitur. Convenit enim aliquam similem rationem dicere montis aenei, puta quod est corpus aeneum in altum et usquequaque diffusum; et tamen adhuc restat quaerere an sit aliquid tale in rerum natura. Et hoc ideo quia termini, idest rationes definitivae, non declarant quod illud de quo assignantur, aut sit aut possibile sit esse; sed semper, assignata tali ratione, licet quaerere quare oporteat tale aliquid esse. Sic igitur patet quod impossibile est quod simul demonstretur quid est et quia est.	Then (92b18) he presents the third reason. Now this reason uses ordinary definitions as examples to manifest the same fact that was concluded in the previous reason, namely, that one who demonstrates the quid est is not demonstrating the quia est. Wherefore he says that it is clear not only in the light of the foregoing but also in view of the modes of terms, i.e., of definitions, which are presently in vogue that those who define do not manifest the quia est. For example, one who defines a circle as something all the lines from whose center to the circumference are equal, is still left with the question why there must be such a thing as he has defined, i.e., why it is necessary to posit that there exists such a thing as was defined; for example, why it is required to posit that there is a circle which is defined in the way mentioned. For it is acceptable to give a like description of a brass mountain by saying, for example, that it is a brass body which is lofty and extensive; but the task would still remain to establish whether there is such a thing in nature. And this because terms, i.e., defining notions, do not state that their counterpart either exists or is capable of existing; rather, whenever such a notion is formulated, it is legitimate to ask why such a thing should exist. Clearly then, it is impossible to demonstrate quid est and quia est simultaneously.
lib. 2 l. 6 n. 6 Deinde cum dicit: si ergo definiens demonstrat etc., ostendit quod non potest ostendi quod quid est definitione, ducendo ad inconveniens. Unde primo, ostendit quid ex hoc sequatur; secundo, ostendit illud quod sequitur esse inconveniens; ibi: sed inconveniens et cetera.	Then (92b26) by leading to something absurd, he shows that the quod quid cannot be shown by demonstration. First, therefore, he shows what would follow from this. Secondly, he shows that what does follow is unacceptable (92b28).
Dicit ergo primo quod, cum ille qui definit, possit ostendere vel quid est, vel tantum quid significat nomen, non propter hoc oportebit quod definitio sit manifestativa ipsius quod quid est, quod proprie ad definitionem pertinet: alioquin sequetur quod definitio significans quod quid est, nihil sit aliud quam ratio significans idem quod nomen: non enim super talem rationem addit aliquid definitio, nisi quia significat essentiam alicuius rei. Unde si non sit aliqua res, cuius essentiam definitio significet, nihil differt definitio a ratione exponente significationem alicuius nominis.	He says therefore (92b26) that since a definer might show either the quid est or merely what a name signifies, it follows that a definition does not necessarily manifest the quod quid, which belongs to definition in the proper sense; otherwise, it will follow that a definition signifying quod quid is nothing more than a statement signifying in the same way that a name does: for the only thing that a definition adds to such a notion is that it signifies the essence of some thing. Hence, if there is no thing whose essence the definition signifies, it will be no different from a statement explaining the signification of some name.
lib. 2 l. 6 n. 7 Deinde cum dicit: sed inconveniens est etc., ostendit inconveniens esse quod definitio nihil sit aliud quam ratio exponens nominis significationem. Et hoc tribus rationibus. Quarum prima est, quia contingit etiam ea quae nec sunt substantia, nec sunt universaliter entia, aliquo nomine significare. Quodlibet autem nomen per aliquam interpretationem exponi potest. Si ergo nihil aliud esset definitio quam ratio interpretativa nominis, sequeretur quod definitio posset esse non substantiarum et totaliter non entium. Quod patet esse falsum. Ostensum est enim in VII Metaph. quod definitio principaliter quidem est substantiae, aliorum autem in quantum se habent ad substantiam.	Then (92b28) he shows that it is unacceptable for a definition to be nothing more than a statement explaining the signification of a name: and this for three reasons. The first of these is that it happens that even things which are neither substances nor beings in a universal sense can be signified by a name. Now a name can be explained by some interpretation. Consequently, if a definition were nothing more than a statement interpreting a name, it would follow that a definition could be given of non-substances and of things that do not exist at all. But this is clearly false, for as 4t is shown in Metaphysics VII, definition bears principally on substance and on other things insofar as they are related to substance.
lib. 2 l. 6 n. 8 Secundam rationem ponit ibi: amplius omnes rationes etc.; quae talis est. Cuilibet rationi, idest orationi aliquid significanti, est imponere aliquod nomen ei correspondens, quod per illam rationem manifestatur. Si ergo nihil aliud sit definitio quam ratio interpretativa nominis, sequeretur quod omnes rationes essent definitiones: et ita sequetur quod, cum disputamus vel colloquimur ad invicem, ipsae disputationes vel collocutiones nostrae sint quaedam definitiones; et similiter sequetur quod Ilias, idest poema Homeri de bello Troiano, sit quaedam definitio.	Then (92b30) he gives the second reason and it is this: To any notion, i.e., to any statement signifying something, it is possible to apply a corresponding name which is explained by that notion. Therefore, if a definition is nothing more than a notion explaining a name, it would follow that all notions were definitions. As a consequence, it would follow that when we dispute or converse with anyone, the disputations or our discussions are definitions; similarly, it would follow that the Iliad, i.e., Homer’s poem about the Trojan War, is a definition.
lib. 2 l. 6 n. 9 Tertiam rationem ponit ibi: amplius neque una scientia etc.; quae talis est. Nulla scientia demonstrat quod tale nomen significet talem rem. Nomina enim significant ad placitum; unde oportet hoc supponere secundum voluntatem instituentis. Manifestum est autem quod in qualibet scientia dantur aliquae definitiones. Manifestum est ergo quod definitiones non significant hoc, scilicet solam nominis interpretationem.	Then (92b32) he gives the third reason and it is this: No science demonstrates that a given name signifies a given thing. For names are arbitrary i signs; hence they must be used according to the will of the one inventing them. But it is obvious that definitions are given in every science. Therefore, it is obvious that definitions do not signify this, i.e., a mere interpretation of a name.
lib. 2 l. 6 n. 10 Deinde cum dicit: ex his igitur neque definitio etc., epilogat quae disputative praemissa sunt. Et dicit quod ex praemissis videtur sequi quod definitio et syllogismus non sunt idem, neque de eodem; et quod definitio nihil demonstret, quia non est de eodem de quo est demonstratio. Et similiter videtur esse ostensum quod non est possibile cognoscere quod quid est, neque per definitionem, neque per demonstrationem; quia definitio solum ostendit quid, et demonstratio ostendit quia est. Sed ad cognitionem quod quid est requiritur cognitio quia est, ut dictum est.	Then (92b35) he sums up what has been so far discussed disputatively. And he says that from the foregoing it is seen to follow that definition and syllogism are neither the same nor concerned with the same; and furthermore that a definition demonstrates nothing, since it is not concerned with the same thing as a demonstration. In like manner, it seems to have been shown that it is not possible to know quod quid either by a definition or a demonstration, bcause a definition merely shows the what and a demonstration the quia. But to know the quod quid a knowledge of quia est is required, as has been shown.

Lecture 7 The two ways, logical and demonstrative, of manifesting quod quid

Latin	English
	Lecture 7 (93a1-b21) THE TWO WAYS, LOGICAL AND DEMONSTRATIVE, OF MANIFESTING QUOD QUID
lib. 2 l. 7 n. 1 Postquam philosophus disputative inquisivit qualiter cognoscatur definitio et quod quid est, hic determinat veritatem. Et primo, dicit de quo est intentio; secundo, exequitur propositum; ibi: quoniam autem sicut diximus etc.; tertio, epilogat quae dicta sunt; ibi: manifestum est igitur ex dictis et cetera. Dicit ergo primo quod iterum post disputativum processum, considerandum est, determinando veritatem, quid praedictorum dicatur bene et quid non bene: et hoc tam circa ipsam definitionem, ut consideremus quid sit ipsa definitio, quam etiam circa ipsum quod quid est, ut consideremus utrum possit aliqualiter manifestari demonstratione vel definitione, vel nullo modo.	After inquiring disputatively how the definition and the quod quid are known, the Philosopher here determines the truth. First, he states what his intention is. Secondly, he carries out what he proposes (93a4). Thirdly, he summarizes (94a13) [end of L. 8]. He says therefore first (93a1) that after the disputative process we must once more consider, but this time by establishing the truth, how much of the foregoing has been well stated and how much not well stated: and this both in regard to definition, by considering what a definition is, and in regard to quod quid, by considering whether it might somehow or other be manifested through a definition or a demonstration or not at all.
lib. 2 l. 7 n. 2 Deinde cum dicit: quoniam autem sicut diximus etc., exequitur propositum. Et primo, quantum ad ipsum quod quid est; secundo, quantum ad definitionem, quae est ratio significativa eius; ibi: definitio autem quoniam dicitur ratio et cetera. Circa primum, ponit duos modos manifestandi quod quid est. Et primo, ponit modum logicae probationis; secundo, modum demonstrativae probationis; ibi: quo autem modo contingat et cetera.	Then (93a4) he carries out what he has proposed. First, in regard to the quod quid. Secondly, in regard to definition which is a statement signifying it (93b28). Concerning the first he sets down two methods of manifesting the quod quid. First, the method of logical proof. Secondly, the method of demonstrative proof (93a16).
Circa primum, resumit primo id quod supra manifestatum est, scilicet quod idem est scire quid est, et scire causam quaestionis an est; sicut idem est scire propter quid, et scire causam quaestionis quia est. Ratio autem huius, scilicet quod idem sit scire quid est, et scire causam ipsius si est, ista est, quia oportet quod eius quod est rem esse, sit aliqua causa: propter hoc enim dicitur aliquid causatum, quod habet causam sui esse.	Regarding the first he reviews first of all (93a4) that which was established above, namely, that it is the same thing to know quid est and to know the cause involved in the question an est, just as it is the same thing to know propter quid and to know the cause involved in the question quia est. The reason for this, i.e., for the fact that it is the same thing to know the quid est and the cause involved in the si est, is that there must be some cause of the fact that a thing exists, for something is referred to as caused by reason of the fact that it has a cause of its existing.
Haec autem causa essendi aut est eadem, scilicet cum essentia ipsius rei, aut alia. Eadem quidem, sicut forma et materia, quae sunt partes essentiae; alia vero, sicut efficiens et finis: quae quidem duae causae sunt quodammodo causae formae et materiae, nam agens operatur propter finem et unit formam materiae. Et si accipiamus causam quae est alia ab essentia rei, quandoque quidem est causa talis per quam possit fieri demonstratio, quandoque autem non. Non enim ex omni causa agente sequitur ex necessitate effectus. Ex suppositione autem finis sequitur quod sit id quod est ad finem, ut probatur in II physicorum.	Now the cause of existing is either the same, i.e., the same as the essence of a thing, or something not the same: the same, indeed, as matter and form, which are parts of the essence; not the same, as agent and end, which two causes are somehow the cause of the form and matter, for the agent acts for an end and unites the form to the matter. And if we consider the cause which is other than the essence of a thing, sometimes it is such a cause that a demonstration can be formed in virtue of it, and sometimes not. For the effect does not follow of necessity from every efficient cause; but from the supposition of the end it follows that what is required for the end also exists, as is proved in Physics II.
lib. 2 l. 7 n. 3 Supponamus ergo quod sit aliquis effectus, cuius esse causa sit non solum ipsa essentia rei, sed habeat etiam aliquam aliam causam, et sit talis per quam possit demonstrari; puta si dicamus quod si homo pertingit ad beatitudinem, necesse est praeexistere virtutem. Accipiamus autem quod essentia virtutis sit habitus operans secundum rationem rectam. Potest ergo demonstrari esse aliquem habitum secundum rectam rationem operantem, si sit aliquis habitus ad beatitudinem perducens. Accipiatur ergo pro medio illa causa alia, quae est demonstrativa, et formetur syllogismus in prima figura: quod necesse est fieri, quia oportet quod quid est universaliter et affirmative praedicari de re cuius est. Syllogizabitur ergo sic: omnis habitus perducens ad beatitudinem est habitus secundum rectam rationem operans; sed virtus est huiusmodi; ergo et cetera. Concludit ergo quod iste modus, qui est nunc inquisitus, est unus modus ostendendi quod quid est per aliud, quod est causa. Et quod iste modus sit conveniens patet, quia necesse est, sicut supra dictum est, quod medium ad probandum quod quid est accipiatur ipsum quid est, et similiter medium ad probandum aliqua propria accipiatur aliquid proprium.	So let us suppose that an effect exists which has as its cause not only the essence of the thing but also another cause such that something can be demonstrated through it; for example, we might say that if a man has attained happiness, it is necessary that virtue pre-exist. Now let us assume that the essence of virtue is a habit which operates according to right reason. Therefore, it can be demonstrated that there is a habit which operates according to right reason, if there is a habit conducive to happiness. Let that other cause, therefore, which is demonstrative, be taken as the middle, and let a syllogism be formed in the first figure (which must be done, because the quod quid must be universally and affirmatively predicated of the thing of which it is the quod quid): the syllogism then will be: “Every habit conducive to happiness is a habit operating according to right reason; but virtue is such a habit: therefore... He concludes, therefore, that this method which is now being examined is one method of showing the quod quid through something else which is a cause. And this method is evidently suitable, because, as was established above, it is necessary that the middle taken for proving quod quid be the quid est; and similarly that the middle taken for proving properties be something proper.
Est autem considerandum quod, cum quid est sit causa ipsius esse rei, secundum diversas causas eiusdem rei potest multipliciter quod quid est eiusdem rei assignari. Puta quod quid est domus potest accipi per comparationem ad causam materialem, ut dicamus quod est aliquid compositum ex lignis et lapidibus; et etiam per comparationem ad causam finalem, ut dicamus quod est artificium praeparatum ad habitandum. Sic ergo continget quod, cum sint multa quod quid est eiusdem rei, aliquod illorum monstrabitur, et aliquod non monstrabitur, sed supponetur. Unde non sequitur quod sit petitio principii, quia aliud quod quid est supponitur, et aliud probatur. Nec tamen est modus probandi quod quid est demonstrative, sed logice syllogizandi; quia non sufficienter per hoc probatur quod id quod concluditur, sit quod quid est illius rei de qua concluditur, sed solum quod insit ei.	But there is the further consideration that since the quid est is the cause of the very being of the thing, then according to the diverse causes of one thing, there are various ways of assigning the quod quid of the same thing. For example, the quod quid of house can be formulated in terms of its material cause, so that we might say that it is something composed of wood and stones; and also in terms of the final cause, namely, that it is an artifact constructed for habitation. Thus, therefore, it will occur that since there are several quod quid’s of the same thing, one of them will be demonstrated and another not demonstrated but supposed. Hence it does not follow that there is a begging of the question, because one quod quid is supposed and the other proved. Nor is this a method proving the quod quid demonstratively, but of syllogizing it logically, because by this method it is not sufficiently proved that what is concluded is the quod quid of the thing of which it is concluded, but merely that it is in it.
lib. 2 l. 7 n. 4 Deinde cum dicit: quo autem modo etc., ostendit quomodo per demonstrationem possit accipi quod quid est. Et circa hoc duo facit: primo, ostendit quomodo manifestetur quod quid est per demonstrationem in aliquibus; secundo, ostendit quod non est ita in omnibus; ibi: est autem quorumdam et cetera. Circa primum tria facit: primo, praemittit quaedam quae sunt necessaria ad propositum ostendendum; secundo, manifestat propositum; ibi: quorum igitur habemus etc.; tertio, epilogat; ibi: quomodo quidem igitur et cetera.	Then (93a16) he shows how by demonstration the quod quid can be achieved. Regarding this he does two things. First, he shows how the quod quid can be manifested in certain instances through demonstration. Secondly, he shows that it is not so in all cases (93b22) [L. 8]. Concerning the first he does three things. First, he lays down certain things needed for showing what he proposes. Secondly, he manifests what he has proposed (93a28). Thirdly, he summarizes (93b15).
lib. 2 l. 7 n. 5 Circa primum praemittit tria; quorum primum est comparatio quaedam ipsius quod quid est ad propter quid. Dicit ergo quod ad ostendendum quomodo contingat accipere quod quid est per demonstrationem, oportet iterum a principio resumere.	With respect to the first (93a16) he lays down three things. The first of these is a comparison between the quod quid and the propter quid. He says, therefore, that in order to show how it occurs that the quod quid can be achieved through demonstration, we must start once more from the beginning.
Ubi considerandum occurrit quod dupliciter se habet aliquis ad cognoscendum propter quid. Quandoque enim habemus quia in nostra cognitione, et quaerimus adhuc propter quid; quandoque autem simul manifesta sunt nobis utraque; tertium autem est impossibile, ut scilicet prius cognoscat aliquis de aliqua re propter quid quam quia. Et similiter est de eo quod quid erat esse: quia aliquando scimus rem esse, nec tamen perfecte scimus quid sit; aliquando autem simul scimus utrumque; sed tertium est impossibile, ut scilicet sciamus quid est, ignorantes si est.	The first thing to be considered is the fact that a person may be in either of two states as regards knowledge of the propter quid. For sometimes we have the quia in our knowledge and are still seeking the propter quid; and sometimes both are manifest to us at one time. A third case is impossible, namely, that one know the propter quid of something before the quia. And the same holds for the quod quid erat esse: sometimes we know a thing to be without perfectly knowing the quid sit; sometimes we know both at once. Again, a third case is impossible, namely, to know quid est without knowing if it is.
lib. 2 l. 7 n. 6 Secundum ponit ibi: hoc autem si est etc.; et dicit quod rem aliquam esse possumus scire, absque eo quod sciamus perfecte quid est, dupliciter. Uno modo, secundum quod cognoscimus aliquod accidens eius, puta si per velocitatem motus existimemus leporem esse; alio modo, per hoc quod cognoscimus aliquid de essentia eius. Quod quidem est possibile in substantiis compositis, ut puta si comprehendamus hominem esse per hoc quod est rationalis, nondum cognitis aliis, quae complent essentiam hominis. In substantiis vero simplicibus hoc non contingit; quia non potest cognosci aliquid de substantia simplicis rei, nisi tota cognoscatur, ut patet in IX Metaphys.	Then (32a21) he lays down the second preliminary remark, saying that there are two ways in which we might know something to be without perfectly knowing the quid est: in one way, insofar as we might know one of its accidents, as for example, when by the speed of its motion we judge that something is a hare; in another way, by knowing something of its essence. This of course is possible in the case of a composite substance, as when we comprehend something to be a man in virtue of the fact that it is rational, without yet knowing the other items which complete the essence of man. However, in simple substances this does not occur, because one cannot know anything concerning the substance of a simple thing without knowing the entire essence, as is clear from Metaphysics IX.
Oportet autem quod qui cognoscit aliquam rem esse, per aliquid rei illud cognoscat: et hoc vel est aliquid praeter essentiam rei, vel aliquid de essentia ipsius. Et de hoc ponit exemplum, puta si cognoscamus tonitruum esse, propter hoc quia percipimus quemdam sonum in nubibus: quod quidem pertinet ad essentiam tonitrui; non tamen est tota tonitrui essentia, quia non omnis sonus nubium est tonitruum. Et similiter si cognoscamus defectum, idest eclipsim solis vel lunae esse, propter hoc quod est quaedam privatio luminis; cum tamen non omnis privatio luminis sit eclipsis. Et eadem ratio est si aliquis percipiat hominem esse, propter hoc quod est quoddam animal; vel si percipiat animam esse, propter hoc quod est aliquid seipsum movens.	At any rate, a person who knows some thing to be must know it through something of that thing, namely, something outside the essence of the thing or something pertaining to its essence. And he clarifies this with the example of knowing thunder to be, because we perceive a sound in the clouds—which of course pertains to the essence of thunder, albeit not the entire essence, because not every sound in the clouds is thunder—or of knowing a defect, i.e., an eclipse, of the sun or moon to be, because there is a failure of light-although not every failure of light is an eclipse. And the same applies if someone perceives a man to be, because there is an animal; or a soul to be, because something is moving itself.
lib. 2 l. 7 n. 7 Tertium ponit ibi: sed quaecunque quidem etc.; et dicit quod illa de quibus scimus quia sunt per aliquod accidens ipsorum, nullo modo per hoc se habent ad hoc quod cognoscamus de ipsis quid est; quia nec etiam per huiusmodi accidens vere scimus ea esse. Scimus quidem esse eorum accidentia; sed quia accidentia non sunt ipsae res, non propter hoc vere scimus ipsas res esse. Vanum autem est quaerere quid est, si aliquis nesciat quia est; sed illa de quibus scimus ea esse per aliquid ipsorum, facilius possunt cognosci a nobis quid sunt. Unde manifestum est quod sicut nos habemus ad cognoscendum quia est aliquid, ita nos habemus ad cognoscendum quid est.	Then (93a24) he sets forth the third preliminary remark, saying that those things which we know to exist through some accident belonging to them are such that there is no correlation between this knowledge and knowledge of their quid est, because in virtue of such accidents we do not even truly know that they are. We do of course know these accidents to be theirs, but because the accidents are not the things themselves, we do not thereby know that the things themselves exist. Moreover, it is fruitless to seek the quid est if one does not know quia est; but those things which we know to exist through something of their own can be more easily known by us as to what they are. Hence it is plain that as we are in regard to knowing that something is, so we are in regard to knowing what it is.
lib. 2 l. 7 n. 8 Deinde cum dicit: quorum igitur habemus aliquid etc., manifestat propositum secundum praemissa; et dicit quod in his quae scimus esse per hoc quod cognoscimus aliquid essentiae eius, accipiamus primo tale exemplum. Sit defectus, idest eclipsis, in quo a, quae est maior extremitas; luna in quo c, quae est minor extremitas; oppositio terrae directa inter lunam et solem in quo b, quod est medium. Idem igitur est quaerere utrum deficiat luna vel non, et quaerere utrum b sit vel non: quaerere autem utrum b sit vel non, nihil differt quam quaerere si est aliqua ratio ipsius defectus. Nam b, idest oppositio terrae, est ratio defectus lunae; et si sit oppositio terrae, et illud dicimus esse, scilicet defectum lunae. Aut similiter si quaeramus qualis sit ratio contradictionis, utrum scilicet in habendo duos rectos vel non habendo sit contradictio.	Then (93a28) in the light of the foregoing he manifests what he proposed. And he says that in regard to a thing which we know exists because we know something of its essence, let us consider the following example in which A, the major extreme, is defect, i.e., eclipse; and in which C, the minor extreme, is moon; and interposition of the earth between sun and moon is B, the middle. In this case, therefore, to ask whether the moon is eclipsed or not is the same as to ask whether B exists or not; but to ask whether B exists or not is to ask if there is some reason for that eclipse. For B, i.e., the interposition of the earth, is the reason for the moon’s eclipse; and if there is an interposition of the earth we say that the other exists, i.e., the eclipse of the moon. Or, similarly, if we should seek the reason for one side of a contradiction, i.e., does it lie in having or in not having two right angles.
Cum autem inveniamus esse id quod quaerimus, puta esse defectum, simul sciemus quia et propter quid, si inveniatur propositum per medium debitum, quod est causa. Si vero non, sed per aliquod extrinsecum, sciemus quia, sed non propter quid. Puta si sit luna c et defectus a, accipiamus pro medio, quod est b, hoc quod luna non potest facere umbram aliquo nostrum medio existente, cum sit plenilunium. Luna enim, quandocunque non deficit, facit umbram interposito aliquo corpore: sed hoc quod est non posse facere umbram, non est causa defectus, sed potius effectus. Si ergo b praedicetur de c (quia scilicet luna non potest in plenilunio facere umbram aliquo nostrum medio existente), et iterum si in hoc medio sit a (idest si accipiatur quod quandocunque hoc accidit, luna deficit), manifestum erit lunam deficere. Sed propter quid luna deficiat, nondum erit manifestum. Et similiter sciemus quia est defectus, sed nesciemus quid est defectus, quando manifestum est quod a est in c, idest quod luna deficit.	But when we find that what we seek exists, for example, that there is an eclipse, then we know the quia and the propter quid together, if what is sought is found through an appropriate middle which is the cause; and if not, but it is found through something extrinsic, we will know the quia ‘and not the propter quid. For example, let the moon be C and the eclipse A, and let us take as middle, i.e., B, the fact that the moon, although it is full, is now unable to cause a shadow when we put an object between it and us. For the moon, whenever it is not eclipsed, causes a shadow if some body is interposed; yet the fact that it is now unable to cause a shadow is not the cause of the eclipse, but rather its effect. Therefore, if B be predicated of C (i.e., that the moon is now unable to produce a shadow of an object which is interposed), and if moreover A is true of that middle (i.e., if we assume that whenever this happens, the moon is eclipsed), it will be plain that the moon is eclipsed. But it will not yet be clear why the moon is eclipsed. Similarly, we will know that there is an eclipse but not know what an eclipse is, when we know that A is in Q i.e., that the moon is eclipsed.
Et sicut in praedicto exemplo nec scitur propter quid est, nec scitur quid est, ita quaerere propter quid est, nihil aliud est quam quaerere quid est. Puta si quaeramus quare deficit luna, utrum deficiat propter hoc quod obiicitur terra in medio inter solem et lunam; vel hoc fiat per conversionem lunae, ut scilicet tunc vertatur versus nos superficies lunae quae est tenebrosa, ut quidam dixerunt; vel etiam lunare lumen extinguatur in aliquo humido. Quaerere autem utrum propter aliquam harum causarum fiat defectus lunae, nihil est aliud quam quaerere utrum defectus lunae sit obiectio terrae, aut conversio lunae, aut extinctio luminis eius. Et hoc medium est ratio alterius extremitatis, sicut in praemissis exemplis est ratio ipsius a, quod est maior extremitas; quia defectus lunae nihil est aliud quam obiectio facta lunari lumini a terra.	Now just as in this example neither the propter quid nor the quid is known, so to inquire why [i.e., propter quid] something is, is the same as to inquire [quid], i.e., what it is. Thus, if we should ask propter quid, i.e., why the moon is eclipsed, namely, is it because the earth is between the sun and moon, or because the moon has turned, i.e., because the dark side of the moon has been turned toward us, as some say, or even because the light of the moon has been extinguished in something moist: to ask whether it is due to any of these causes that the moon is eclipsed is nothing more than to ask whether the eclipse of the moon consists in the interposition of the earth, or the turning of the moon, or the extinction of its light. And this middle is the reason of the other extreme: thus, in the foregoing example, it is the reason for A which is the major extreme, because the eclipse of the moon is nothing more than the moon’s light being blocked by the earth.
Ponit etiam aliud exemplum: ut si quaeramus quid est tonitruum. Et dicatur, secundum opinionem Anaxagorae et Empedoclis, quod est extinctio ignis in nube. Secundum vero opinionem eius in II Meteororum, tonitruum fit ex percussura exhalationis siccae in frigiditate ad nubes. Utitur autem multoties in exemplis opinionibus aliorum. Si ergo secundum praedictam opinionem quaeratur, propter quid tonat: respondetur, propter hoc quod extinguitur ignis in nube. Sit igitur nubes c, quod est minor extremitas; tonitruum a, quod est maior extremitas; extinctio ignis sit b, quod est medium. Syllogizetur ergo sic: in c est b, idest in nube est extinctio ignis; sed omnis extinctio ignis est sonus; ergo in nube est sonus tonitrui. Et sic patet quod accipiendo propter quid, per demonstrationem accipimus quid est, quia ipsum medium ostendens propter quid, est ratio definitiva primi termini, idest maioris extremitatis. Sed si oporteat accipere aliquod aliud medium ad hoc demonstrandum, hoc assumetur ex reliquis rationibus, idest ex definitione minoris extremitatis, et aliarum causarum extrinsecarum. Cum enim subiectum sit causa passionis, necesse est quod definitio passionis demonstretur per definitionem subiecti. Et hoc patet in exemplo proposito. Quia enim luna est corpus natum sic moveri, ideo necesse est quod obiiciatur certo tempore terra inter solem et ipsam.	He gives a further example, namely, inquiring what is thunder. According to the opinion of Anaxagoras and Empedocles it is the quenching of fire in a cloud; although according to his own opinion in Meteorology II, thunder is caused by a dry exhalation in a cold environment beating against a cloud. But he frequently uses the opinions of others in his examples. So, if according to the above-mentioned opinion, one should ask why it thunders, the answer might be given that it is because fire is being quenched in a cloud. Therefore, let the cloud be C, the minor extreme, and thunder A, the major extreme, and the quenching of fire B, the middle. Then we may syllogize in the following manner: “In C is B, i.e., in the cloud is a quenching of fire; but every quenching of fire is a sound: therefore in the cloud is a sound of thunder.” And thus it is clear that to arrive at the propter quid through demonstration, we take the,quid est, because the very middle which shows the propter quid is a statement defining the first term, i.e., defining the major extreme. But if we had to take some other middle to demonstrate this, it would be taken from the remaining statements, i.e., from the definition of the minor extreme and of other extrinsic causes. For since the subject is the cause of its proper attribute, it is required that the definition of the proper attribute be demonstrated by the definition of the subject. And this is clear in the other example; for since the moon is a body fixed by nature to move in such and such a way, it is necessary that at some time the earth be interposed between it and the sun.
lib. 2 l. 7 n. 9 Deinde cum dicit: quomodo quidem igitur etc., epilogat quod dictum est: et dicit dictum esse quomodo accipiatur et innotescat quod quid est, scilicet per hoc quod accipitur propter quid. Dictum est etiam quod non est syllogismus neque demonstratio ipsius quid est, ut scilicet proprie syllogizetur vel demonstretur quod quid est; et tamen manifestatur quod quid est per syllogismum et per demonstrationem, in quantum scilicet medium demonstrationis propter quid est quod quid est. Unde manifestum est quod neque sine demonstratione potest cognosci quod quid est, cuius est altera causa; nec tamen est demonstratio ipsius quod quid est, sicut probabatur in obiiciendo. Et secundum hoc obiectiones inductae sunt verae.	Then (93b15) he sums up what has been said, saying that we have shown how the quod quid is taken and made known, namely, by taking the propter quid. We have also said that there is neither syllogism nor demonstration of the quid est in the sense of properly syllogizing or demonstrating the quod quid, although the quod quid is manifested by syllogism and demonstration, insofar as the middle in a propter quid demonstration is the quod quid. Hence, it is clear that a quod quid having another cause cannot be known without a demonstration, but the demonstration is nevertheless not of the quod quid, as was proved in the objections. And according to this the above objections are true.

Lecture 8 To attain quod quid through demonstration is not possible in all cases. Relation of definition to demonstration

Latin	English
	Lecture 8 (93b22-94a19) TO ATTAIN QUOD QUID THROUGH DEMONSTRATION IS NOT POSSIBLE IN ALL CASES RELATION OF DEFINITION TO DEMONSTRATION
lib. 2 l. 8 n. 1 Postquam philosophus ostendit quod in quibusdam per demonstrationem accipitur quod quid est, hic ostendit quod hoc non est possibile in omnibus. Et ad hoc ostendendum praesupponit quod quorumdam est quaedam altera causa, quorumdam autem non. Quia igitur quod quid est accipitur per demonstrationem, cuius medium est causa, manifestum est quod sunt quaedam, quorum quod quid est oportet accipere sicut quoddam immediatum principium; ita quod oportet supponere de tali re et esse et quid est, vel manifestare aliquo alio modo quam per demonstrationem, puta per effectum vel per simile vel aliquo tali modo.	After showing that in some instances the quod quid is acquired through demonstration, the Philosopher now shows that this is not possible in all. And in order to show this he repeats (93b22) that of some things there is a cause other than the thing, but of other things not. Therefore, because the quod quid is acquired by a demonstration whose middle is a cause, it is manifest that there are certain things whose quod quid must be taken as an immediate principle, in the sense that one must suppose both the to be and the quid of that thing, or manifest it by some means other than demonstration, say by an effect or by a likeness or some other way.
lib. 2 l. 8 n. 2 Est autem considerandum quod hoc quod dicit, quorumdam non esse aliam causam, potest intelligi tripliciter. Uno modo, quod simpliciter et absolute causam non habet sui esse. Et hoc competit soli primo principio, quod est causa esse et veritatis in omnibus rebus. Nihil enim prohibet etiam eorum quae ex necessitate sunt, esse aliquam causam necessitatis, ut patet in V Metaphys. Et ideo, cum hic philosophus pluraliter loquatur, non sic est intelligendum quod hic dicitur, quod aliqua sint, quae nullam habent causam sui esse.	Here it should be noted that his statement that some things have a cause not distinct from themselves can be understood in three ways. In one way, it means that it simply and absolutely has not a cause of its being. And this is proper to the First Principle alone, which is the cause of the being and truth of all things. For there is nothing to prevent even things which exist of necessity from having some cause of their necessity, as is stated in Metaphysics V. And therefore, although the Philosopher is speaking in the plural here, his words should not be taken to mean that there are several things which have no cause of their being.
lib. 2 l. 8 n. 3 Alio modo potest intelligi secundum ordinem causarum eiusdem rei. Manifestum est enim in rebus habentibus quatuor causas, quod una causa est quodammodo causa alterius. Quia enim materia est propter formam et non e converso, ut probatur in II Physic., definitio quae sumitur ex causa formali, est causa definitionis, quae sumitur ex causa materiali eiusdem rei. Et quia generatum consequitur formam per actionem generantis, consequens est quod agens sit quodammodo causa formae et definitio definitionis. Ulterius autem omne agens agit propter finem; unde et definitio quae a fine sumitur, est quodammodo causa definitionis quae sumitur a causa agente. Ulterius autem non est procedere in generibus causarum: unde dicitur quod finis est causa causarum. Potest tamen in singulis causarum generibus a posterioribus ad priora procedi; sed definitiones debent dari per causas proximas.	In another way it can be understood as referring to the order of the causes of one thing. For it is clear that in things which have four causes, one cause is somehow the cause of another one. For since matter is fot the sake of form and not vice versa, as is proved in Physics II, a definition which is based on the formal cause is the cause of the definition which is taken from the material cause of the same thing. And because the thing produced obtains a form in virtue of the action of the generator, it follows that the agent is somehow the cause of the form, and the definition the cause of the defined. Furthermore, every efficient cause acts for an end; hence, too, the definition taken from the end is somehow the cause of the definition which is taken from the efficient cause. Beyond this it is impossible to go in the genera of causes: hence the dictum that the end is the cause of the causes. Yet in the individual genera of causes one can proceed from the subsequent to the prior; but definitions should be given through proximate causes.
Et secundum hunc sensum in quibusdam libris interponitur, quod definitiones secundum speciem factae nullum habent medium quo demonstrentur: definitiones autem secundum materiam factae possunt habere medium: quia scilicet definitiones quae dantur secundum causam materialem possunt demonstrari per definitiones quae dantur secundum causam formalem. Definitio autem quae datur secundum causam formalem, non potest ulterius demonstrari per aliquod principium intrinsecum rei, quod proprie pertinet ad quod quid est, utpote intrans essentiam rei. Sed etsi demonstretur per causam efficientem et finalem, dicendum erit quod semper causa superior se habet ut formalis respectu inferioris. Praedicta tamen verba non habentur in libris Graecis. Unde magis videtur esse Glossa, quae per errorem scriptorum introducta est loco textus.	And according to this interpretation we find it stated in certain books that definitions which are made in terms of the species have no middle by which they might be demonstrated: but that definitions made in terms of matter can have a middle, in the sense that definitions which are given according to the material cause, can be demonstrated by those which are given according to the formal cause. But a definition which is given according to formal cause cannot be further demonstrated by an intrinsic principle of the thing which belongs in a proper way to the quod quid as entering into the essence of the thing. But if it were to be demonstrated by the efficient and final cause, one would have to say that a higher cause is related as formal to the lower. However, these words are not present in the Greek version; hence they seem to be a Gloss introduced into the text by a copyist’s error.
lib. 2 l. 8 n. 4 Tertio modo potest intelligi in quantum aliqua sunt, quae non habent causam in genere subiecto alicuius scientiae: sicut in genere numeri, de quo est arithmetica, est devenire ad unitatem, cuius in hoc genere non est accipere aliud principium. Et hic sensus concordat exemplo quod philosophus subiungit, dicens quod arithmeticus supponit quid est unitas et quia est. Et sicut illa quorum non est alia causa, ita etiam illa quae possunt habere medium, et quorum est altera causa, potest manifestari quod quid est: ita tamen quod non demonstretur ipsum quod quid est, sed magis medium demonstrationis ut quod quid est accipiatur.	Thirdly, they could be understood in the sense that there are some things which do not have a cause in the generic subject of some science; as in the genus of number, with which arithmetic is concerned one arrives at unity, which has no principle in this genus. And this sense concurs with the example which the Philosopher adds when he states that the arithmetician accepts what unity is and that it is. And just as in the case of things that do not have something else as cause, so too in the case of things which can have a middle and whose cause is something else, their quod quid can be manifested; in such a way, however, that the quod quid is not demonstrated, but rather that the middle of demonstration is taken as quod quid.
lib. 2 l. 8 n. 5 Deinde cum dicit: definitio autem quoniam etc., ostenso qualiter se habeat quod quid est ad demonstrationem, ostendit quomodo se habeat definitio. Et circa hoc duo facit: primo, ostendit qualiter definitio se habeat ad demonstrationem; secundo, manifestat quod dixerat per exemplum; ibi: differt enim dicere propter quid et cetera. Circa primum tria facit: primo, proponit unum modum definitionis significantis quid est; secundo, proponit alium modum definitionis significantis propter quid; ibi: alia vero terminus etc.; tertio, ostendit qualiter utraque definitio se habeat ad demonstrationem; ibi: quare prima quidem et cetera.	Then (93b28) having shown how the quod quid is related to demonstration, he shows how definition is related to demonstration. Concerning this he does two things. First, he shows how a definition is related to demonstration. Secondly, he uses an example to manifest what he has stated (94a2). In regard to the first he does three things. First, he lays down one type of definition which signifies quid est. Secondly, another type which signifies propter quid (93b38). Thirdly, he shows how each of these definitions is related to demonstration (93b39).
lib. 2 l. 8 n. 6 Circa primum, supponit primo quod definitio sit ratio significativa ipsius quod quid est. Si autem non posset haberi aliqua alia ratio rei quam definitio, impossibile esset quod sciremus aliquam rem esse, quin sciremus de ea quid est; quia impossibile est quod sciamus rem aliquam esse, nisi per aliquam illius rei rationem. De eo enim quod est nobis penitus ignotum, non possumus scire si est aut non. Invenitur autem aliqua alia ratio rei praeter definitionem: quae quidem vel est ratio expositiva significationis nominis, vel est ratio ipsius rei nominatae, altera tamen a definitione, quia non significat quid est, sicut definitio, sed forte aliquod accidens. Sicut forte invenitur aliqua ratio, quae exponit quid significat hoc nomen triangulus. Et per huiusmodi rationem habentes quia est, adhuc quaerimus propter quid est, ut sic accipiamus quod quid est. Sed sicut supra dictum est, hoc difficile est accipere in illis in quibus nescimus an sint. Et huius difficultatis causa superius est assignata: quia scilicet, quando nescimus rem esse per aliquid rei, non absolute scimus si est vel non, sed solum secundum accidens, ut supra expositum est.	In regard to the first he supposes first of all (93b28) that definition is a statement signifying the quod quid. But if no other notion could be had of a thing except the definition, it would be impossible for us to know that some thing is, without knowing the quid est of it; because it is impossible for us to know that a thing is except in virtue of some notion of that thing. For in regard to a thing completely unknown to us, we cannot know if it is or not. But we do find some other notion of a thing besides the definition, namely, a notion which explains the signification of a name, or a notion of the very thing named; which notion, however, is distinct from the definition, because it does not signify the quid est as does a definition, but perhaps some accident. Thus one might find some notion which explains what the word triangle means. Then having the quia est in virtue of this notion, we would seek the propter quid in order that we might thereby arrive at the quod quid. But, as stated above, it is difficult to arrive at this in the case of things whose existence we do not know. Furthermore, the cause of this difficulty was mentioned above, namely, because when we do not know a thing to be by means of something of that thing, we do not know absolutely if it is or is not, but only according to an accident, as was explained above.
Ad distinguendum autem rationem significantem quid est ab aliis, subiungit quod dupliciter aliqua ratio potest dici una. Quaedam enim est una, sola coniunctione: per quem modum etiam habet unitatem Ilias, idest poema de historia Troiana. Et per hunc etiam modum dicitur esse una ratio, quae est expositiva nominis, vel manifestativa ipsius rei nominatae per aliqua accidentia: ut si dicatur quod homo est animal risibile susceptibile disciplinae. Alia vero ratio est una in quantum simpliciter significat unum de re una, cuius est ratio, et hoc non secundum accidens. Et talis ratio est definitio significans quid est, quia essentia cuiuslibet rei est una. Sic igitur concludit quod illa quae dicta est, est una definitio definitionis, scilicet quod definitio est ratio ipsius quod quid est.	Then in order to distinguish the notion signifying the quid est from the other notions, he adds that there are two ways in which a notion can be said to be one. For some are one by junction only: in this way even the Iliad, i.e., the poem of the history of Troy, possesses a unity. And this is the way the notion which explains a name or describes the thing named through its accidents is one, as when it is stated that man is a risible animal capable of discipline. But a notion is also one insofar as it simply signifies one thing about one thing of which it is the notion, and this not in virtue of some accident. And such a notion is the definition signifying quid est, because the essence of anything is one. Thus, therefore, he concludes that what has been said, namely, that a definition is a notion of the quod quid, is one definition of a definition.
lib. 2 l. 8 n. 7 Deinde cum dicit: alia vero terminus est etc., ponit alium modum definitionis; et dicit quod alia definitio definitionis est, ut sit ratio manifestans propter quid.	Then (93b38) he lays down another type of definition, saying that another definition of definition is that it is a notion manifesting the propter quid.
lib. 2 l. 8 n. 8 Deinde cum dicit: quare prima quidem etc., ostendit quomodo utraque definitio se habeat ad demonstrationem, concludens ex praemissis quod prima definitio solum significat quod quid est, sed non demonstrat ipsum. Secunda vero definitio est quasi demonstratio quaedam ipsius quod quid est: et non differt a demonstratione nisi sola positione, id est ordine terminorum et propositionum.	Then (93b39) he shows how each of these definitions is related to demonstration, concluding from the foregoing that the first definition merely signifies, but does not demonstrate the quod quid; whereas the second definition is, as it were, the definition of the quod quid and differs from a demonstration by position alone, i.e., in the ordering of the terms and propositions.
lib. 2 l. 8 n. 9 Deinde cum dicit: differt enim dicere propter quid etc., manifestat quod dixerat per exempla. Et circa hoc duo facit: primo, manifestat per exempla quae dicta sunt; secundo, colligit ex praemissis diversitatem definitionum; ibi: immediatorum autem definitio et cetera. Dicit ergo primo quod differt dicere propter quid tonat, et quid est tonitruum: quia secundum opinionem illorum qui dicunt quod extinctio ignis in nube est causa tonitrui, dicit aliquis propter quid cum dicit tonitruum esse propter hoc quod ignis extinguitur in nube.	Then (94a2) he uses examples to manifest what he had said. In regard to this he does two things. First, he shows by examples what has been said. Secondly, from the foregoing he gathers the various kinds of definition (940). He says therefore (94a2) that it is one thing to say why it thunders and another what thunder is: because according to the opinion of those who state that the quenching of fire in a cloud is the cause of thunder, one is giving the propter quid when he asserts thunder to be due to the fact that fire is quenched in a cloud; whereas one who asserts that thunder is the sound of fire being quenched in a cloud is stating what thunder is.
Ille autem dicit quid est tonitruum, qui dicit quod est sonus ignis extincti in nubibus. Utrumque autem horum significat eamdem rationem, sed per alium modum. Nam cum dicitur tonat propter hoc quod extinguitur ignis in nube, significatur per modum demonstrationis continuae, idest non distinctae per diversas propositiones; accipiuntur tamen continue omnes termini demonstrationis. Cum autem dicitur quod tonitruum est sonus extincti ignis in nubibus, significatur per modum definitionis. Sed si dicamus quod tonitruum est sonus in nubibus, nulla mentione facta de extinctione ignis, erit definitio significans quid est, et erit solum demonstrationis conclusio.	Now each of these signifies the same notion but not in the same way. For when one states that it thunders because fire is being quenched in a cloud, the notion is signified after the manner of a continuous demonstration, i.e., not broken down into explicit propositions; yet all the terms of a demonstration are continually being taken. But when it is asserted that thunder is the sound of fire being quenched in the clouds, the notion is signified after the manner of a definition. But if we were to say that thunder is the sound in the clouds, no mention being made of the quenching of fire, it will be a definition signifying quid est, and will be merely the conclusion of a demonstration.
lib. 2 l. 8 n. 10 Deinde cum dicit: immediatorum autem definitio etc., colligit ex praemissis quot sunt modi definitionum per respectum ad demonstrationem. Et primo, resumit quoddam quod supra dixerat, quod eorum quae non habent causam, definitiones sunt accipiendae sicut quaedam immediata principia. Et ideo dicit hic quod definitio immediatorum, idest rerum non habentium causas, est sicut quaedam indemonstrabilis positio eius quod quid est.	Then (94a9) he gathers together from the foregoing how many modes of definition there are insofar as they are relevant to demonstration. First, he repeats something previously stated, namely, that in the case of things which do not have a cause, their definitions are to be taken as immediate principles. Hence he says here that the definition of “immediate things,” i.e., of things not having causes, is as an indemonstrable positing of the quod quid.
Ex hoc ergo concludit quod triplex est genus definitionis per comparationem ad demonstrationem. Quaedam enim est definitio, quae est indemonstrabilis ratio eius quod quid est; et haec est illa, quam dixerat esse immediatorum. Alia vero est definitio, quae est quasi quidam syllogismus demonstrativus eius quod quid est; et non differt a demonstratione nisi casu, idest secundum diversam acceptionem et positionem dictionum; ut cum dicitur, tonitruum est sonus extincti ignis in nubibus. Tertia autem est definitio, quae est solum significativa ipsius quod quid est, et est conclusio demonstrationis.	From this, therefore, he concludes that there is a threefold genus of definition when considered relative to demonstration. For there is one definition which is an indemonstrable notion of a thing’s quod quid: this is the one which he said concerns immediate things. Another definition is that which is, as it were, a demonstrative syllogism of a thing’s quod quid and differs from a demonstration merely by structure, i.e., by a different acceptance and position of the phrasing, as when it is stated that thunder is the sound of fire being quenched in the clouds. The third is the definition which only signifies quod quid and is the conclusion of a demonstration.
lib. 2 l. 8 n. 11 Deinde cum dicit: manifestum igitur ex dictis etc., epilogat quae dicta sunt; et dicit manifestum esse ex praedictis per quem modum est demonstratio ipsius quod quid est, et per quem modum non: quia scilicet quod quid est potest accipi ex ipsa demonstratione, non autem potest demonstrari. Dictum est etiam in quibus possit esse demonstratio eius quod quid est, secundum modum praedictum, quia in habentibus causam; et in quibus non, quia in non habentibus causam. Dictum est etiam quot modis dicitur definitio: quia scilicet quaedam significat quod quid est, quaedam autem etiam manifestat propter quid. Dictum est etiam quomodo quod quid est demonstratur, in quantum scilicet significatur per definitionem significantem solum quod quid est; et quomodo non demonstratur, in quantum scilicet per definitionem accipitur non solum quid, sed etiam propter quid. Dictum est etiam quomodo definitio se habeat diversimode ad demonstrationem, et quomodo contingat quod eiusdem sit demonstratio et definitio, et quomodo hoc non contingat.	Then (94a13) he summarizes what has been said, declaring that it is plain from the foregoing in what way there is demonstration of the quod quid and in what way not; namely, that the quod quid can be taken from a demonstration but cannot be demonstrated. The things have also been pointed out in which there can be demonstration of the quod quid according to the manner indicated (namely, in things having a cause) and those in which there cannot be (namely, in things not having a cause). It has also been indicated in how many ways definition is said to be: namely, that some signify quod quid, and others even the propter quid. It has also been stated how quod quid is demonstrated, namely, so far forth as this is signified by a definition which signifies only quod quid; and how it is not demonstrated, namely, insofar as in virtue of the definition not only the quid but also the propter quid are taken. It has also been pointed out how definition is related in various ways to demonstration; and how it comes about that there is demonstration of the definition of a same thing, and how this does not come about.

Lecture 9 Propter quid can be manifested in four genera of causes

Latin	English
	Lecture 9 (94a20-95a9) PROPTER QUID CAN BE MANIFESTED IN FOUR GENERA OF CAUSES
lib. 2 l. 9 n. 1 Postquam philosophus ostendit qualiter ipsum quid est se habeat ad demonstrationem, hic ostendit quomodo ad demonstrationem se habeat propter quid, quod significat causam. Et circa hoc duo facit: primo, ostendit quomodo causae assumantur in demonstratione; secundo, quomodo diversimode in diversis rebus; ibi: eadem autem causa est et cetera. Circa primum duo facit: primo, proponit quod intendit; secundo, manifestat propositum; ibi: et hoc enim existente et cetera.	After showing how the quid est functions relative to demonstration, the Philosopher now shows how the propter quid, which signifies the cause, functions relative to demonstration. In regard to this he does two things. First, he shows how causes are taken in a demonstration. Secondly, how diversely in diverse things (95a10) [L. 10]. Concerning the first he does two things. First, he proposes what he intends. Secondly, he manifests what he has proposed (94a24).
lib. 2 l. 9 n. 2 Dicit ergo primo quod quia scire opinamur cum sciamus causam, ut in primo habitum est, demonstratio autem est syllogismus faciens scire; ita consequens est quod medium demonstrationis sit causa. Sunt autem quatuor genera causarum, ut in II Physic. et in V Metaphys. plenius manifestatur. Quarum una est quod quid erat esse, idest causa formalis, quae est completiva essentiae rei. Alia autem est causa, qua posita necesse est causatum poni; et haec est causa materialis, quia ea quae sequuntur ex necessitate materiae, sunt necessaria absolute, ut habetur in II Physic. Tertia autem causa est, quae est principium motus, idest causa efficiens. Quarta autem causa est, cuius gratia fit aliquid, scilicet causa finalis. Et ita patet quod per medium demonstrationis omnes hae causae manifestantur; quia quaelibet harum causarum potest accipi ut medium demonstrationis.	He says therefore first (94a20) that, as was established in the first book, because we think we know in a scientific manner when we know the cause, and a demonstration is a syllogism causing us to know in a scientific manner, the consequence is that the middle of a demonstration is a cause. But there are four genera of causes as is more fully explained in Physics II and Metaphysics V. One of these is the quod quid erat esse, i.e., the formal cause, which is the completeness of a thing’s essence. Another is the cause which, if placed, the caused must also be placed: this is the material cause, because things which follow on the necessity of matter are necessary absolutely, as is established in Physics II. The third is the cause which is the source of motion, i.e., the efficient cause. But the fourth is that for the sake of which something is performed, namely, the final cause. And so it is clear that through the middle in a demonstration all these causes are manifested, because each of these causes can be taken as the middle of a demonstration.
lib. 2 l. 9 n. 3 Deinde cum dicit: et hoc enim quod etc., manifestat quod dixerat. Et circa hoc duo facit: primo, ostendit quomodo diversae causae sumuntur ut media demonstrationis in diversis rebus; secundo, ostendit quomodo unius et eiusdem rei possunt esse diversae causae; ibi: contingit autem idem et cetera. Circa primum quatuor facit: primo, manifestat quomodo causa materialis accipiatur in demonstratione; secundo, manifestat propositum in causa formali; ibi: at vero ipsius etc.; tertio, ostendit idem de causa efficienti; ibi: propter quid autem Medorum etc.; quarto autem, in causa finali; ibi: quorumcunque autem et cetera. Circa primum duo facit: primo, proponit modum quo causa materialis assumitur in demonstratione, qui etiam competit aliis causis; secundo, ponit exemplum; ibi: manifestum est autem et cetera.	Then (94a24) he manifests what he had said. In regard to this he does two things. First, he shows how the various causes are taken as middles of demonstration in various things. Secondly, he shows how there can be various causes of the same thing (94b27). Concerning the first he does four things. First, he shows how the material cause is taken in demonstration. Secondly, he manifests his point in regard to the formal cause (94a35). Thirdly, he does the same in regard to the efficient cause (94a36). Fourthly, in regard to the final cause (94b8). Regarding the first he does two things. First, he sets forth the way in which the material cause is taken in a demonstration; a way, namely, that applies also to the other causes. Secondly, he presents an example (94a28).
lib. 2 l. 9 n. 4 Dicit ergo primo quod illud, quo existente necesse est aliud esse, scilicet causa materialis, non contingit accipi sic, ut ex necessitate aliquid sequatur, si accipiatur una sola propositio; sed oportet accipere ad minus duas hoc modo se habentes, quod communicent in uno medio. Si ergo accipiatur in duabus propositionibus unum medium, quod est causa materialis, ex necessitate sequitur conclusio: puta si dicamus: omne compositum ex contrariis est corruptibile; lapis est huiusmodi; ergo et cetera. Oportet autem accipere duas propositiones, non solum propter exigentiam formae syllogisticae, sed etiam quia non omnia quae sunt ex materia, habent ex materia necessitatem, ut probatur in II Physic. Et ideo praeter propositionem in qua sumitur hoc habere talem materiam, oportet quod sumatur alia propositio, quae declaret quod ex tali materia aliquid ex necessitate sequatur.	He says therefore first (94a24) that that which once it exists, something else must also exist, namely, a material cause, is not to be so taken that something follows of necessity if one proposition alone is taken; rather, one must take at least two which are so related that they communicate in one middle. Therefore, if one middle which is the material cause be taken in two propositions, a conclusion follows of necessity; as if we were to say: “Everything composed of contraries is corruptible; but a stone is such: therefore, a stone is corruptible.” Now it is required that two propositions be taken, not only because the syllogistic form demands it, but also because not all things which are from matter have necessity from the matter, as is proved in Physics II. And therefore, besides the proposition in which it is stated that this has matter, another must be taken which declares that from such matter something follows of necessity.
lib. 2 l. 9 n. 5 Deinde cum dicit: manifestum autem est etc., proponit exemplum in mathematicis. Nec est contra id quod dicitur in III Metaphys., quod mathematicae scientiae non demonstrant per causam materialem. Mathematica enim abstrahit quidem a materia sensibili, non autem a materia intelligibili, ut dicitur in VI Metaphys.: quae quidem materia intelligibilis consideratur secundum quod aliquid divisibile accipitur vel in numeris vel in continuis. Et ideo quandocunque in mathematicis aliquid demonstratur de toto per partes, videtur esse demonstratio per causam materialem: partes enim se habent ad totum secundum rationem materiae, ut habetur in II Physic. Et quia materia magis proprie dicitur in sensibilibus, propter hoc noluit eam nominare causam materialem, sed causam necessitatis.	Then (94a28) he presents an example from mathematics. Now this does not conflict with the statement in Metaphysics III that mathematical sciences do not demonstrate through material cause: for although mathematics abstracts from sensible matter, yet not from intelligible matter, as it is stated in Metaphysics VI. This matter is considered intelligible precisely insofar as something divisible is taken in numbers or in continua. Therefore, in mathematics whenever something is demonstrated of a whole through the parts, it seems to be a demonstration through material cause: for the parts are compared to the whole according to the notion of matter, as is stated in Physics II. And because matter is more properly said of sensible things, he preferred not to name it material cause, but a cause of necessity.
lib. 2 l. 9 n. 6 Ad evidentiam autem exempli quod in litera ponitur, sciendum est quod omnis angulus cadens in semicirculo est rectus, ut probatur in III Euclidis. Est autem probatio talis. Sit semicirculus abc; chorda autem eius, quae est diameter circuli, dividatur per medium in puncto d, quod est centrum circuli. Erigatur ergo super punctum d linea perpendicularis, quae attingat circumferentiam circuli in puncto b; a quo ducantur duae lineae ad duo puncta a et c. Dico ergo quod angulus abc, cadens in semicirculo, est rectus. Probatio. Triangulus bdc habet tres angulos aequales duobus rectis; sed angulus eius bdc est rectus, quia linea bd est perpendicularis; ergo duo alii anguli, scilicet dbc et bcd, sunt aequales uni recto. Sed hi duo anguli sunt aequales, eo quod duae lineae db et dc sunt aequales, quia protrahuntur a centro ad circumferentiam; relinquitur ergo quod angulus dbc sit media pars recti anguli. Pari quoque modo probatur quod angulus abd sit media pars recti. Ergo totus angulus abc est rectus.	To understand the example in the text it should be noted that every angle inscribed in a semicircle is a right angle, as is proved in Euclid III in the following way: Given a semicircle ABC such that its chord, namely, the diameter of the whole circle, is cut in half at the point D which is the center of the circle. From this point D draw a perpendicular line which touches the circumference of the circle at point B,from which are drawn two lines, one to point A and one to point C. He says, therefore, that angle ABC which falls within the semicircle is a right angle. And the proof is this: Triangle BDC has three angles equal to two right angles; but its angle BDC is a right angle, because BD is perpendicular to DC. Therefore, its other two angles, namely, DBC and BCD are equal to one right angle. But these two angles are equal, because the lines BD and DC are equal; since they proceed from the center to the circumference. It follows therefore that angle DBC equals one half a right angle. In the same way it is proved that angle ABD equals one half a right angle. Therefore, the entire angle ABC is a right angle.
Hac ergo probatione utitur hic philosophus, dicens quod manifestum est per hunc modum, propter quid est recta quae in semicirculo, idest rectus angulus qui cadit in semicirculo, dum accipit illud, quo existente sequitur quod sit rectus. Sit ergo rectus angulus in quo a, quod est maior extremitas; medietas duorum angulorum sit medium, in quo est b; angulus cadens in semicirculo sit minor extremitas, in quo est c. Huius igitur quod est a esse in c, idest quod angulus in semicirculo sit rectus, causa est b, scilicet quod angulus semicirculi est medium duorum rectorum. Hoc enim medium est aequale per conversionem ipsi a, et ipsum c est simili modo aequale ipsi b. Nam b est esse medietatem duorum angulorum rectorum. Hoc igitur existente, necesse est quod a sit in c; quod nihil est aliud quam angulum semicirculi esse rectum. Subiungit autem quod hic modus demonstrationis potest etiam ad causam formalem pertinere, quam nominaverat quod quid erat esse; eo quod esse medium duorum rectorum potest accipi ut ratio significans quod quid est recti anguli.	This, proof, therefore, the Philosopher uses here, saying that in this way is shown why “that is right which falls in a semicircle,” i.e., why the angle which falls in a semicircle is a right angle, when that is given which, when it exists, it follows that it is a “right.” Therefore let right angle be A, the major extreme; the half of two right angles, the middle, be B; and angle falling in a semicircle, the minor extreme, be C. Now the cause of A’s being in C, i.e., of the angle in the semicircle’s being right is B, namely, that the angle of a semicircle is half of two right angles. For this half is by conversion equal to A; in like manner, C is equal to B For B consists in being the half of two right angles. Therefore, since this is the case, it is necessary that A be in C, which is nothing else than for the angle of a semicircle to be right. He further adds that this method of demonstration can also pertain to the formal cause (which he called quod quid erat esse) on the ground that being half of two right angles can be taken as an expression signifying the quod quid of a right angle.
lib. 2 l. 9 n. 7 Deinde cum dicit: at vero et ipsius etc., remittit ad praemissa, et dicit quod in superioribus monstratum est quomodo causa formalis, quae est quod quid erat esse, pertineat ad medium demonstrationis.	Then (94a35) he returns to what has been previously established and states that it was shown there how the formal cause which is the quod quid erat esse pertains to the middle of demonstration.
lib. 2 l. 9 n. 8 Deinde cum dicit: propter quid autem etc., ponit exemplum de causa movente, tangens quamdam Graecorum historiam: videlicet quod Athenienses quondam, adiunctis sibi quibusdam aliis Graecis, invaserunt Sardenses, qui erant subiecti regi Medorum; et ideo Medi invaserunt Athenienses. Dicit ergo quod quaeri potest propter quid bellum Medorum factum est cum Atheniensibus; et hoc propter quid est causa quare Athenienses impugnati sunt a Medis: quia scilicet ipsi simul cum quibusdam aliis, scilicet Eretriis, fecerunt, insultum in Sardenses; hoc enim est quod fuit primum motivum belli. Sit ergo bellum in quo a, quod est maior extremitas; quod priores insultum fecerunt sit b, idest medium; sed Athenienses sit c, idest minor extremitas. Igitur b est in c, in quantum scilicet Atheniensibus convenit quod priores fecerunt insultum. A autem est in b, quia scilicet illi qui prius aliis iniustitiam intulerunt, sunt debellati. Sic ergo a est in b, in quantum debellantur illi qui prius inceperunt. Hoc autem, scilicet b, quod est medium, pertinet ad Athenienses, qui prius bellum inceperunt. Et sic patet quod hic accipitur quasi medium causa quae primo movit.	Then (94a36) he gives an example of the movent cause, touching on an event from the history of the Greeks, namely, that the Athenians, allying themselves with certain other Greeks, once invaded the Sardians who were subject to the king of the Medes; and for that reason the Medes invaded the Athenians. He says, therefore, that one might ask propter quid [i.e., why] the war of the Medes with the Athenians occurred; and this propter quid would be the cause why the Athenians were attacked by the Medes, namely, because the former along with certain allies, namely, the Eretrians, made an assault upon the Sardians: for this was the first motive of the war. Therefore, let war be the major extreme, A, and the first to attack be the middle, B, but Athenians, the minor extreme, C. Therefore B is in C, so far forth namely as it belongs to the Athenians that they were the first to make an assault. But A is in B, because namely the ones who were first to work an injustice were in turn warred upon. Thus, therefore, A is in B, inasmuch as they were attacked who first launched the war. But this, namely, B, which is the middle, pertains to the Athenians who first began the war. And thus it is clear that in this example the cause which first moved is taken as middle.
lib. 2 l. 9 n. 9 Deinde cum dicit: quorumcunque autem causa etc., manifestat idem in causa finali. Et circa hoc duo facit: primo, proponit exemplum in causa finali; secundo, ostendit differentiam inter causam finalem et causam quae est principium motus; ibi: generationes autem e contrario et cetera.	Then (94b8) he manifests the same thing in the final cause. Concerning this he does two things. First, he sets forth an example in final cause. Secondly, he shows the difference between the final cause and the cause which is the source of motion (94b23).
Dicit ergo primo quod similiter se habet cum praedictis in quibuscunque accipitur quasi causa finis, cuius causa fit aliquid. Puta si dicamus propter quid aliquis ambulat post coenam, ut scilicet fiat sanus: et iterum propter quid est domus, ad hoc scilicet ut vasa, idest supellectilia hominis, salventur, idest conserventur. Sic ergo hoc, scilicet ambulatio post coenam, fit gratia sanandi; hoc autem, scilicet aedificatio domus, est gratia servandi supellectilia. Sic ergo nihil differt dicere propter quid oportet post coenam ambulare, et cuius gratia hoc oporteat. Sic ergo ambulare post coenam in quo c, minor extremitas; sed non eminere cibos in ore stomachi sit medium, in quo est b; sanari vero sit maior extremitas, in quo est a. Sit ergo b in c, quia ambulatio post coenam facit ut non emineant cibi in ore stomachi; et propter hoc provenit sanitas, quod est a esse in b. Videtur enim quod ipsi ambulare, quod est c, insit b, quod est non eminere cibos in ore stomachi. Ad hoc autem sequitur a, quod est esse sanativum. Sic ergo patet quod b, scilicet non eminere cibos in ore stomachi, est causa quare c est a, idest quare ambulare post coenam sit sanativum; et hoc, scilicet non eminere cibos in ore stomachi, est ratio eius quod est esse sanativum. A enim, idest esse sanativum, sic assignabitur, idest notificabitur. Quod autem b sit in c est propter quid, quia scilicet sic se habere ut non emineant cibi in ore stomachi est sanari. Et ad hoc quod singula fiant magis manifesta, oportet transumere rationes, ut scilicet accipiatur medium quasi ratio maioris extremitatis, sicut in praemisso exemplo apparet.	He says therefore first (94b8) that it happens in like manner in all cases where the cause taken is the end for the sake of which something is done: for example, if we should state propter quid [i.e., for what purpose] someone walks after dinner, namely, to be made healthy; and again propter quid [i.e., for what] does a house exist, namely, so that the vessels, i.e., a man’s belongings, may be kept safe. Thus, therefore, this, namely, walking after dinner is done for the sake of health; this other, namely, the building of a house is for the sake of keeping belongings safe. Thus, there is no difference in saying propter quid [i.e., for what purpose] one should walk after dinner and that for the sake of which this is necessary. So let walk after dinner be C, the minor extreme; but food not to rise to the entrance of the stomach be B, the middle; and be made healthy be A, the major extreme. Hence let B be in C, because walking after dinner brings it about that food does not rise to the entrance of the stomach; and for this reason one is made healthy, which is for A to be in B. For it is seen that to C which is walk belongs B, which is that food does not rise to the entrance of the stomach. From this follows A, which is to be made healthy. Thus, therefore, it is clear that B, namely, that the food does not rise to the entrance of the stomach is the cause why C is A, i.e., why walking after dinner is healthful: and this, namely, that foods do not rise to the entrance of the stomach is involved in the notion of being kept healthy. For A, i.e., to be healthful, will be thus explained, i.e., made known. But the fact that B is in C is propter quid, namely, because to be healthy consists in being in such a state that foods do not rise to the opening of the stomach. And in order that each of these be better understood one should arrange the reasons, so that the middle will be taken as the reason of the major extreme, as appears in the above example.
lib. 2 l. 9 n. 10 Deinde cum dicit: generationes autem e contrario etc., ostendit quomodo diversimode se habet et in causa quae est principium motus. Contrario enim modo se habent in via generationis causa finalis, et causa quae est principium motus. Nam ibi, scilicet in demonstratione quae sumitur per causam quae est principium motus, oportet medium primum fieri, idest esse primum in via generationis; sicut prius fuit quod Athenienses insultum fecerunt in Sardenses, quam quod impugnarentur a Medis. Sed hic, in demonstratione quae fit per causam finalem, accipitur sicut primum in via generationis ipsum c, quod est minor extremitas, et est ultimum causatum causae finalis. Ultimum autem in via generationis est finis, cuius gratia est aliquid. Manifestum est enim quod primo aliquis ambulat post coenam, et ex hoc sequitur quod cibi non emineant in ore stomachi, et ex hoc ulterius sequitur sanitas hominis, quae est principalis finis.	Then (94b23) he shows how the situation is otherwise in the cause which is the principle of motion. For in the order of generation the final cause and the cause which is the principle of motion behave in contrary ways. For there, namely, in the demonstration which is based on the cause which is the principle of motion, the middle must eventuate first, i.e., be first in the order of generation, just as the Athenians assaulted the Sardians before being attacked by the Medes. But here, in the demonstration which is based on final cause, the first to be taken in the order of generation is C, which is the minor extreme; and the last, the effect of the final cause. But in the way of generation the last thing is the end for the sake of which something is done. For it is obvious that one first of all walks after dinner, and on that follows the fact that foods do not rise to the entrance of the stomach, upon which further follows the man’s health which is the chief end.
lib. 2 l. 9 n. 11 Deinde cum dicit: contingit autem idem etc., ostendit quomodo ad eumdem effectum possunt assumi plures praedictarum causarum. Et circa hoc duo facit: primo, manifestat plures causas esse eiusdem; secundo, ostendit in quibus habeat locum quod dictum est; ibi: plurima autem huiusmodi sunt et cetera. Dicit ergo primo quod contingit unum et eumdem effectum esse propter aliquem finem sive gratia eius, et ex necessitate alicuius prioris causae; sicut hoc quod est lumen apparere per pellem lucernae, ex necessitate provenit; necesse est enim quod corpus minorum partium transeat per poros largiores. Dicitur autem hoc secundum opinionem ponentium quod lumen sit corpus quoddam subtile, et quod apparentia luminis per diaphanum fiat propter magnitudinem pororum quasi quorumdam foraminum. Corpus autem subtile videtur esse parvarum partium. Et quia hoc non est secundum suam opinionem, subiungit quod ex tali necessitate hoc provenit, si tamen lumen appareat digrediendo, idest per egressum partium eius per poros diaphani. Hoc autem quod est apparere lumen per pellem lucernae, est propter aliquem finem, ut scilicet ambulantes in nocte beneficio luminis non offendamus.	Then (94b27) he shows how for the same effect several of the aforesaid causes can be taken. In regard to this he does two things. First, he manifests that there are several causes of a same thing. Secondly, he shows the cases in which this is applicable (94b35). He says therefore first (94b27), that it happens that one and the same effect exists because of an end or for its sake, and also from the necessity of some prior cause: thus, the fact that light appears through the skin of a lantern comes about of necessity; for it is necessary that a tiny body pass through pores that are larger. Now this is said according to the opinion of those who posit light as a subtle body, and the appearance of light through a transparency as occurring because of the size of the pores which are regarded as openings. But a subtle body seems to be comprised of tiny parts. And because this is not according to his own opinion, he adds that this arises from that sort of necessity, namely, if light does appear by passing through, i.e., by the passing of its parts through the pores of the transparency. But the appearing of light through the skin of a lantern occurs for some end, namely, in order that with the help of the light we might walk at night without stumbling.
In talibus ergo possibile est dupliciter argumentari. Uno modo a causa praeexistente, ut dicamus: si esse contingit hoc, et hoc erit; puta si lumen impositum est lucernae, sequitur quod diffundatur per poros pellis. Alio modo a causa posteriori, quae est posterior in fieri; et secundum hoc argumentabimur quod si fieri contingit finem ultimum, oportet praecedere ea per quae pervenitur ad finem. Sicut patet in tonitruo quod si est ignis extinctus, necesse est sizire, idest facere fremitum quemdam ignis extincti et sonum quemdam. Et si opinio Pythagoricorum est vera, quod tonitruum fiat ad comminandum his qui sunt in Tartaro, oportet dicere quod tonitruum fiat ad hoc quod homines qui sunt in Tartaro timeant.	In such cases, therefore, it is possible to argue in two ways: in one way from a pre-existing cause, as when we say that if this occurs then this other will occur; for example, if a light is set in a lantern, it follows that it will be diffused through the pores of the skin. In another way from a posterior cause which is posterior in the order of becoming. According to this, one will argue that if some ultimate end comes to pass, it is required that those items precede through which the end is attained, as is clear in thunder; which if it is quenched fire, it is necessary that it hiss, i.e., make the sound and roar of fire being quenched. And if the opinion of the Pythagoreans is true that thunder takes place to strike terror into the denizens of Tartarus, then one should say that thunder takes place to the end that the men in Tartarus shudder.
lib. 2 l. 9 n. 12 Deinde cum dicit: plurima autem huiusmodi etc., ostendit in quibus contingat hoc quod dictum est. Et circa hoc tria facit: primo, ostendit quomodo hoc se habeat in his quae sunt a natura; secundo, quomodo se habeat in his quae sunt a proposito; ibi: in his autem quae sunt etc.; tertio, infert quoddam corollarium; ibi: quare finis bonus et cetera. Dicit ergo primo quod plurima huiusmodi, quae scilicet sunt ex necessitate et fiunt propter finem, maxime inveniuntur in his quae subsistunt a natura, et in his quae sunt per naturam constructa. Natura enim quaedam facit propter finem, quaedam vero facit ex necessitate priorum causarum. Quae quidem est duplex: una secundum naturam, quae est secundum conditionem materiae; alia secundum causam moventem: sicut lapis movetur quidem ex necessitate quandoque sursum, quandoque deorsum, sed non propter idem genus necessitatis; sed deorsum movetur propter necessitatem naturae, sursum autem propter necessitatem moventis, idest proiicientis.	Then (94b35) he shows in which things this occurs that has been said. In regard to this he does three things. First, he shows how this is in regard to things which are from nature. Secondly, with things that are done intentionally (95a3). Thirdly, he draws a corollary (954). He says therefore first (9035), that very many of these, namely, which are from necessity and are done for an end, are found chiefly in things which subsist by nature and in things which are constructed by nature. For nature makes certain things, acting for an end, and certain things it makes from the necessity of prior causes. This latter is twofold: one, according to nature, which is according to the condition of the matter; the other, according to movent cause’ as a stone is moved by necessity sometimes upwards and sometimes downwards, but not on account of the same type of necessity: it is moved downward on account of a necessity of nature, but upward on account of a necessity of the mover, i.e., of the one casting it.
lib. 2 l. 9 n. 13 Deinde cum dicit: in his autem etc., ostendit quomodo se habeat in his quae sunt a proposito. Et dicit quod in illis quae fiunt per rationem, sicut sunt opera artis, quaedam talia sunt quae nunquam fiunt a casu, sicut domus et statua, nec etiam possunt unquam fieri ex necessitate naturae; sed semper fiunt propter finem, quia semper fiunt a ratione, quae non operatur nisi intendens finem.	Then (95a3) he shows how this is in regard to things that proceed from intention. And he says that in things that are done through reason (as works of art are), some are such that they never occur by chance; for example, a house and a statue, and never from the necessity of nature: but they are always done for an end, because they are always done by reason, which does not act without intending an end.
Quaedam vero sunt quae possunt quidem fieri a ratione artis, tamen possunt etiam quandoque fieri a fortuna: sicut patet de sanitate, quae quandoque fit per artem medicinae; sed tamen, quia potest provenire ex aliqua causa naturali, potest contingere quod aliquis sanetur praeter intentionem, sicut si leprosus sanetur ex esu serpentis, quem comedit ut moreretur. Et similiter contingit de salute; cum scilicet aliquis intrans domum propter aliquid aliud, liberatur de manu inimicorum quaerentium ipsum. Et hoc maxime contingit in omnibus rebus in quibus contingit quod aliquid fit et sic et aliter, cum non a fortuna fit, idest cum contingit eumdem effectum non fortuito ex diversis causis provenire. Puta potest aliquis intrare domum non a fortuna ut salvetur a manu hostium, vel ut comedat, vel ut quiescat. Unde si intendendo unum eorum eveniat aliud, erit a fortuna. Sed domus et statua non fiunt nisi per easdem causas; et ideo talia non contingit fieri a fortuna.	However, there are certain things which can indeed be produced from the reasoning of art, but can also come about through fortune: as in the case of health, which can sometimes be produced by the art of medicine; but because it can occur from a natural cause, it can happen that someone be healed not intending it, as if a leper should be healed from eating a serpent which he ate to die. The same can happen in regard to safety, namely, when a person entering a house for some other purpose is saved from the hands of enemies hunting him. And this happens mainly in all cases in which something can happen one way or another, when it is not due to fortune, i.e., when a same effect might happen without fortune from various causes. For example, a person might enter a house not by chance in order to be saved from the hand of his enemies or to eat or to rest. Hence, if in intending one of these something else occurs, it will be from fortune. But a house and a statue cannot be produced except by identical causes and therefore such things cannot be done by fortune.
lib. 2 l. 9 n. 14 Deinde cum dicit: quare finis bonus etc., concludit ex praemissis quod pervenire ad bonum est aut a natura aut ab arte. Ars enim et natura similiter operantur propter finem, ut habetur in II Physic. Sed a fortuna non fit aliquid gratia huius. Quod ideo dicitur, quia etsi fortuna contingat in his quae fiunt propter aliquid, ut dicitur in II Physic., illud tamen quod dicitur a fortuna fieri, non est intentum tanquam finis, sed praeter intentionem accidit.	Then (95a7) he concludes from the foregoing that arrival at a good is either by nature or by art. For art and nature operate in similar fashion for an end, as is stated in Physics II. But what is done by fortune is not done of set purpose. He says this because even though fortune may be involved in things that are being done for something, as it is stated in Physics II, nevertheless that which is said to be done by fortune is not intended as an end, but happens outside one’s intention.

Lecture 10 How something is demonstrated through a cause not simultaneous with its caused.

Latin	English
	Lecture 10 (95a10-b1) HOW SOMETHING IS DEMONSTRATED THROUGH A CAUSE NOT SIMULTANEOUS WITH ITS CAUSED HOW A CAUSE NOT SIMULTANEOUS WITH ITS EFFECT IS TAKEN AS MIDDLE IN DEMONSTRATING
lib. 2 l. 10 n. 1 Postquam philosophus ostendit quomodo quatuor genera causarum in demonstrationibus pro mediis assumuntur, hic ostendit quomodo in diversis demonstratur aliquid per causam. Est autem circa hoc duplex differentia consideranda: prima quidem secundum quod causa simul est cum effectu vel non simul; secunda prout causa producit effectum semper aut sicut frequenter; et de hac agit ibi: sunt autem quidem quaedam quae fiunt universaliter et cetera. Circa primum duo facit: primo, ostendit quomodo aliquid demonstretur per causam quae est simul cum eo cuius est causa; secundo, quomodo demonstratur aliquid per causam quae non est simul cum eo cuius est causa; ibi: in his autem quae non simul et cetera.	After showing how the four genera of causes are used as middles in demonstrating, the Philosopher now shows how in different cases something is demonstrated through a cause. But there are two differences to be noted in this regard: the first difference is whether the cause is or is not simultaneous with its effect; the second difference is whether the cause produces its effect always or only as a general rule—this second difference will be discussed later (96a8) [L. 12]. Concerning the first he does two things. First, he shows how something is proved through a cause which is simultaneous with that of which it is the cause. Secondly, how something is demonstrated through a cause which is not simultaneous with that of which it is the cause (95a23).
lib. 2 l. 10 n. 2 Circa primum considerandum est quod, quia in motu necesse est considerare prius et posterius, in causis motus est accipere causam et causatum se habere secundum prius et posterius. Sicut patet quod causa agens naturalis movendo perducit ad suum effectum: et sicut per totum motum perducitur mobile ad terminum motus, ita per primam partem motus perducitur ad secundam, et sic deinceps. Unde sicut motus est causa quietis consequentis, ita prima pars motus est causa subsequentis, et sic deinceps.	In regard to the first point it should be noted that since one is involved with the notions of prior and subsequent when he analyzes motion, so too in considering the causes of motion one must take into account that the cause and the caused are related as prior and subsequent. For it is obvious that a natural agent causes its effect by moving something. Furthermore, just as the movable object is brought to the terminus of its motion by virtue of the entire motion, so by virtue 0~1 the first part of that motion it is brought to the second part, and so on. Hence, just as the entire motion is the cause of the subsequent state of rest, so the first part of the motion is the cause of the subsequent part, and so on.
Et hoc indifferenter sive hoc consideretur in uno mobili, quod movetur continue a principio usque ad finem; sive in diversis mobilibus, quorum primum movet secundum, et secundum tertium. Et licet simul dum primum movens movet, primum motum moveatur, tamen primum motum remanet movens postquam desiit moveri, quo movente simul movetur secundum mobile. Et ita successive moventur mobilia, quorum unum est causa motus alterius, sicut de his quae proiiciuntur manifestat philosophus in VIII Physic. Per hunc ergo modum contingit quod causa non est simul cum eo cuius est causa, in quantum scilicet prima pars motus est causa secundae, vel primum motum movet secundum.	This analysis is true whether we confine ourselves to one object which is being moved without interruption from beginning to end, or to several objects the first of which moves the second and the second the third. And although at the same time that the first mover is moving its object that object is being moved, nevertheless the object thus moved continues to act as mover even after it stops being moved. Consequently, while it is acting as mover, another object is being moved. In this way several moveable objects are successively moved in such a way that one is the cause of the motion of another, and so on, as happens in the case of thrown objects whose motion the Philosopher explained in Physics VIII. Therefore, in this example it turns out that the cause is not simultaneous with that of which it is the cause, namely, inasmuch as the first part of the motion is the cause of the second part, or the first moved object moves the second.
Quamvis autem motus in suis partibus successionem habeat, tamen simul est cum causa movente. Simul enim dum movens movet, mobile movetur, eo quod motus nihil est aliud quam actus mobilis a movente, secundum quem movens dicitur movere et mobile moveri. Et multo magis in his quae sunt extra motum, oportet causam simul esse cum suo causato; sive accipiatur aliquid ut terminus motus (sicut illuminatio aeris simul est cum solis exortu), sive aliquid accipiatur in his quae sunt penitus immobilia, et in causis essentialibus, quae sunt causae ipsius esse.	But although the motion has succession in its parts, it is nevertheless simultaneous with its movent cause. For the moveable object is moved at the same time that the mover acts, inasmuch as motion is nothing else than the act existing in the moveable object from the mover, such that in virtue of that act the mover is said to move and the object is said to be moved. Indeed, the requirement that the cause be simultaneous with what is caused must be fulfilled even more in things that are outside of motion whether we take something outside of motion to mean the terminus of the motion-as the illumination of air is simultaneous with the rising of the sun--or in the sense of something absolutely immovable, or in the sense of essential causes which are the cause of a thing’s being.
lib. 2 l. 10 n. 3 Circa primum ergo duo facit: primo, proponit quod intendit; secundo, manifestat propositum per exempla; ibi: ut propter quid factus est defectus et cetera. Dicit ergo primo quod quandocunque causa est simul cum suo effectu, oportet eamdem causam accipere quantum ad hoc quod est fieri vel factum esse vel futurum esse, quae accipitur quantum ad hoc quod est esse: quia si causa est simul cum suo causato, sicut necesse est quod quando est causa est effectus, ita necesse est quod quando fit causa fiat effectus, et quando est facta quod sit factus effectus, et quando est futura quod sit futurus effectus. Nec est instantia quod dum fit aedificator, addiscendo artem aedificativam, nondum fit aedificium, cuius ipse est causa per artem aedificativam; quia aedificator non nominat causam aedificii in actu, sed causam in potentia vel in habitu. Sed aedificans nominat causam in actu, quam oportet simul esse cum eo cuius est causa, ut dicitur in II Physic. Est autem identitas quantum ad hoc, quod in omnibus medium est causa. Sed hoc accipiendum est secundum debitam proportionem; ut scilicet ipsum esse causae proportionetur ipsi esse effectus, et fieri causae fieri causati, et factum esse causae facto esse causati, et futurum esse causae futuro esse causati.	Concerning the first point, therefore, he does two things. First, he states what he intends to establish. Secondly, he clarifies this with examples (95a13). He says therefore first (95a10) that whenever the cause is simultaneous with its effect, it is necessary to take the same cause for the coming to be or the “having come to be” or the future existence, as is taken for the actual existence: for if the cause is simultaneous with that of which it is the cause, then just as it is necessary that when the cause exists, the effect be, so it is necessary that when the cause is coming to be, the effect be coming to be; and when the cause has come to be, the effect should have come to be; and when the cause will have been, the effect will have been. Nor does it avail to object that when a builder is coming to be—while he is learning the art of building—the edifice is not yet being constructed: for “builder” does not stand for the cause in act of the edifice, but for the cause in potency, or as possessed of the skill. But “someone building” denotes the cause in act: it is this cause that must be simultaneous with that of which it is the cause, as it is stated in Physics II. There is identity in the sense that in all these cases the middle is the cause. However, this must be taken according to a due proportion, namely, so that the to be of the cause corresponds to the to be of the effect, and the coming to be of the cause to the coming to be of the effect, and the “having come to be” of the cause to the “having come to be” of the effect, and the future being of the cause to the future being of the effect.
lib. 2 l. 10 n. 4 Deinde cum dicit: ut propter quid factus est defectus etc., manifestat quod dixerat per duo exempla, quorum primum est de eclipsi lunae. Dicimus enim quod heri factus est defectus lunae propter hoc quod heri facta est interpositio terrae inter solem et lunam; et quod nunc fit defectus lunae propter hoc quod nunc fit talis interpositio terrae; et quod cras fiet defectus lunae propter id quod terra ponetur in medio; et quod nunc est defectus lunae propter id quod nunc est interpositio terrae.	Then (95a13) he clarifies what he had said with two examples, the first of which concerns the eclipse of the moon. For we say that there was an eclipse of the moon yesterday, because the earth was interposed between the sun and the moon yesterday; and that an eclipse of the moon is now coming to be, because such an interposition is now coming to be; and that tomorrow there will be an eclipse of the moon, because the earth will be between then; and that there is now an eclipse of the moon, because the earth is now interposed.
Secundum autem exemplum est de crystallo: puta si dicamus quid est crystallus; et accipiatur hoc pro eius definitione, quod sit aqua condensata vehementer. Sit ergo aqua c, idest minor extremitas; et densatum esse sit a, idest maior extremitas; et accipiatur pro medio b, idest quod penitus caret calore. Exhalante enim calido inspissatur humidum: unde quando intense exhalat calidum, consequens est quod intense inspissetur humidum. Reducendo ergo ad formam syllogisticam, dicemus quod b est in c, quia scilicet crystallus habet perfectam exhalationem calidi; in b autem est a, quia illud quod perfecte caret calido, est densatum. Sicut igitur huius quod est crystallum esse aquam plene densatam, causa est quod habeat defectum caloris; ita etiam causa quod fiat crystallus, causa est quod fiat b. Et eadem ratio est in factum esse, et in futurum esse. Et sic concludit quod si sic accipiantur causa et causatum quod sint simul, oportet quod similiter sint simul in fieri, et in esse, et in factum esse, et in futurum esse.	The second example concerns ice. Thus we might state what ice is and take as its definition that it is rigidly congealed water. Therefore, let C be water, i.e., the minor extreme, and A be congealed, i.e., the major extreme, and take B as the middle, i.e., that which completely lacks heat. For when that which is moist gives off heat it congeals; hence when it intensely gives off heat, the moist object becomes very thick and hard. Bringing this into syllogistic form, therefore, we shall say that B is in C, namely, because ice involves a complete giving up of heat; but A is in B, because that which completely lacks heat is congealed. Therefore, just as the fact that it has a deficiency of heat is the cause of ice’s being water which is completely congealed, so the cause of ice’s coming to be is that B is coming to be. And the same holds for having come to be and for future coming to be. And so he concludes that if the cause and the caused are taken to be simultaneous, it is necessary that they be simultaneous in coming to be, in being, in having come to be, and in future coming to be.
lib. 2 l. 10 n. 5 Deinde cum dicit: in his autem quae non simul etc., ostendit quomodo causa quae non est simul cum causato, accipiatur medium demonstrationis. Et primo, in his quae fiunt in directum; secundo, in his quae fiunt circulariter; ibi: quoniam autem videmus et cetera. Circa primum tria facit: primo, proponit quaestionem; secundo, interponit quoddam quod necessarium est praecognoscere ad solutionem quaestionis: ibi: est igitur a posterius facto etc.; tertio, solvit quaestionem; ibi: speculandum est igitur quid est continens et cetera. Circa primum duo facit: primo, proponit quaestionem; secundo, manifestat eam; ibi: sicut videtur nobis et cetera. Movet ergo primo quaestionem utrum in causis quae non simul fiunt cum suis causatis, sit dicere quod causatum secundum tempus continuum consequatur ad causam vel non.	Then (95a23) he shows how a cause which is not simultaneous with its effect is taken as the middle of demonstration. First, in things that come to be in a direct line. Secondly, in things that come to be reciprocally (95b38) [L: 12]. Concerning the first he does three things. First, he states the question. Secondly, he interjects something that must be known in order to solve the question (95a27). Thirdly, he settles the question (95b1) [L. I I]. In regard to the first he does two things. First, he proposes the question. Secondly, he elucidates it (95a24). First therefore (95a23) he proposes the question, namely, whether in the case of causes which are not simultaneous with what they cause, one should say that what is caused follows upon its cause according to a continuous temporal succession, or not?
lib. 2 l. 10 n. 6 Deinde cum dicit: sicut videtur nobis alias etc., manifestat quaestionem. Videmus enim quod aliae sunt causae aliorum non simul cum eis existentes; sicut eius quod est factum esse est alia causa praecedens, quod est fieri; et ipsius fore, idest quod aliquid sit futurum, causa est aliquod futurum fieri; et iterum ipsius fieri causa est aliquid quod prius factum est. Est igitur quaestio: utrum istae causae se consequentes sint in tempore continuo vel non? Hoc enim necessarium est scire demonstratori, quia si non sit continuatio in huiusmodi causis, non erit accipere immediatum principium, quia semper inter duo nunc discontinuata est accipere aliquod medium. Et ideo si illud nunc in quo est effectus, non sit continuum ad illud nunc in quo est causa, erit in medio aliquid accipere quod sit causa media, et sic in infinitum.	Then (95a24) he restates the question more plainly. For we see that some causes of things do not exist at the same time as those things: thus the cause of a “having come to be” is something prior to it, namely, a “coming to be”; and the cause of a “shall have come to be” is a “shall be coming to be”; and again the cause of a “coming to be” is a previous “has come to be.” Therefore, the question is this: Do these causes which follow one upon the other exist in a continuous span of time or not? For it is necessary that the demonstrator know this, because if there is no continuity in these causes, it will not be possible to employ an immediate principle, because between any two discontinuous now’s it is always possible to take something intermediate. Consequently, if that now during which the effect exists is not continuous with that now in which the cause exists, it will be possible to find a cause between them, and so on to infinity.
lib. 2 l. 10 n. 7 Deinde cum dicit: est igitur a posterius facto syllogismus etc., manifestat quoddam quod est necessarium ad solutionem praemissae quaestionis. Et primo, proponit quod intendit; secundo, probat propositum; ibi: neque enim determinati et cetera. Circa primum considerandum est quod, sicut linea est quoddam continuum, punctus autem est quoddam indivisibile quod terminat et dividit lineam; ita etiam ipsum fieri vel moveri est quoddam continuum, ipsum autem quod est motum esse vel factum esse, est quoddam indivisibile, quod potest accipi vel ut terminans totum motum, vel ut dividens motum tanquam finis primae partis motus et principium secundae, sicut patet de puncto quod dividit lineam.	Then (95a27) he explains something that must be understood in order to solve this question. First, he proposes what he intends. Secondly, he proves what he has proposed (95a32). In regard to the first (95a27) it should be noted that just as a line is a continuous thing, but a point is an indivisible which terminates and divides the line, so the process of becoming or of being moved is something continuous, but the fact of having been moved or having come to be is something indivisible which can be taken either as terminating an entire motion or as dividing the motion, in the sense of being the end of the first part and the beginning of the second part of the motion, just as in the case of a point which divides the line.
Sic igitur ipsum factum esse est causa praecedens ipsum fieri cuius est principium; et est effectus consequens illud fieri cuius est terminus. Si ergo debeamus demonstrare, oportet fieri syllogismum demonstrativum a posteriori factum esse ad fieri praecedens; ut si dicamus: hoc factum est; ergo illud prius fiebat. Sed quia et ipsum factum esse est principium ipsius fieri, sive quae facta sunt eorum quae fiunt, consequens est ut similiter se habeat in his quae fiunt; ut scilicet a posteriori fieri syllogizetur ad prius factum; puta si dicamus: sol movetur ad punctum medii coeli; ergo prius motus est ad punctum orientis. Sed a priori non poterit fieri syllogismus ad posterius; ut puta si dicamus quod, quia hoc prius factum est, ideo sequitur quod illud quod est posterius fiat vel factum sit. Et quae ratio est de fieri et de factum esse, eadem ratio est de fore et futurum fieri.	In this way, therefore, a “having come to be” is both a cause which precedes a “coming to be” of which it is the principle, and an effect following the “coming to be” of which it is the terminus. Therefore’ if we are to demonstrate, the demonstrative syllogism must proceed from a subsequent “having come to be” to a previous “coming to be.” Thus, we would say: “This has come to be; therefore that was previously coming to be.” But because the very “having come to be” is the principle of the “coming to be” (or the things that have come to be are the cause of those that are coming to be), it follows that the former is similarly related to the things that are coming to be, namely, that one may syllogize from a subsequent “coming to be” to a prior “having come to be,” as though we were to say: “The sun is being moved to the midst of the heavens; therefore it was previously moved to a point in the east.” But one may not syllogize from what is prior to what is later and say, for example, that because this has first come to be, it follows that what is later is coming to be or has come to be. And what is true of the relationship between coming to be and having come to be applies to what shall have come to be and what will be coming to be.
lib. 2 l. 10 n. 8 Deinde cum dicit: neque enim determinati etc., probat quod dixerat. Et circa hoc duo facit: primo, probat propositum ratione accepta ex parte temporis absolute considerati; secundo, ex parte temporis quod contingit esse medium inter causam priorem et effectum posteriorem; ibi: amplius enim neque indeterminatum et cetera. Dicit ergo primo quod ideo a priori non potest syllogizari ad posterius, quia posito priori non oportet quod sequatur posterius, neque secundum aliquod determinatum tempus, neque simpliciter non determinate.	Then (95a32) he proves what he had said. In regard to this he does two things. First, he proves his proposition with a reason based on the notion of time considered absolutely. Secondly, with a reason based on the time that intervenes between a cause which is prior and an effect which is subsequent (95a39). He says therefore first (95a32) that the reason why one may not syllogize from what is prior to what is subsequent is that the prior having been posited, it is not necessary that the subsequent follow either at some definite time or at some indefinite future time.
Et hoc primo manifestat quantum ad determinatum tempus, puta si dicamus: bibit infirmus potionem; ergo tali die sanabitur. Si enim a priori facto syllogizari possit posterius secundum determinatum tempus, poterit concludi quod quia verum est dicere hoc factum esse, puta infirmum bibisse potionem, quod etiam verum sit dicere hoc factum esse quod posterius est, puta eum esse sanatum. Sed hoc non sequitur, quia potest dari aliquod tempus in quo verum est eum potionem bibisse, et tamen nondum verum est eum sanatum esse, sicut in intermedio tempore inter sumptionem medicinae et sanitatem adeptam.	First, therefore, he manifests this in regard to a definite time, as in the case where we might say: “The patient has drunk the medicine; therefore he will be cured on such and such a day.” For if one could syllogize from a previous fact to something which will occur later at a definite time, it would be possible to conclude that because it is true to say that this has happened, namely, that the patient has drunk the medicine, it will also be true to say that what is subsequent has come to pass, namely, that he has been cured. But this does not follow: because it is possible to discover some time in which it is true to say that he has drunk the medicine but not yet true to say that he has been cured, say the time between the taking of the medicine and the attainment of the cure.
Et hoc est quod dicit, quod ideo praedicta conclusio non sequitur, quia in medio tempore falsum erit dicere quod hoc sit factum, scilicet hunc esse sanatum, quamvis alterum iam sit factum, scilicet eum medicinam bibisse. Et eadem ratio est etiam respectu futuri: non enim possumus concludere: iste nunc medicinam bibit; ergo erit sanatus, pro aliquo tempore determinato; quia hoc non erit verum in quolibet tempore futuro, scilicet in tempore medio.	And this is what he says, namely, that the reason why the aforesaid conclusion does not follow is because during the interim it is false to say that this has taken place, namely, that he has been cured, although the other has already taken place, namely, that he has drunk the medicine. The same reasoning holds in regard to the future. For we cannot condude, “He is now drinking the medicine; therefore he will be cured,” referring to some definite time; because this will not be true for each subsequent period of time, namely, not in the intervening time.
lib. 2 l. 10 n. 9 Secundo, ibi: neque quoniam hoc factum est etc., probat idem quantum ad tempus indeterminatum, puta si dicamus: iste medicinam bibit; ergo sanabitur. Non enim sequitur quod quia hoc factum est, scilicet quod iste medicinam bibit, hoc erit, scilicet sanabitur. Iam enim supra dictum est quod causa quae ex necessitate infert effectum, est simul cum effectu. Et accipitur quasi medium homogeneum, idest unius generis; sicut ad probandum aliqua esse facta in praeterito, accipitur pro medio et causa aliquid quod est factum in praeterito; et similiter futurorum, id quod est futurum; et eorum quae sunt in fieri, id quod est in fieri; et eorum quae existunt, id quod existit. Sed quando sic syllogizatur: hoc factum est; ergo hoc erit; non accipitur medium unius generis, sed unum est prius et aliud posterius. Unde posito priori non sequitur ex necessitate posterius in illis in quibus effectus causarum impediri possunt.	Secondly (95a35). he proves the same point in regard to an unspecified future time, as when we might say, “He is drinking the medicine; therefore he will be cured.” For it does not follow that because this has taken place, namely, that he has drunk the medicine, that this will be, namely, that he will be cured. For it has already been established that a cause which necessarily infers its effect is simultaneous with its effect. Furthermore, the middle which is taken is homogeneous, i.e., of one genus. For example, to prove that certain things have come to be in the past, one takes as the middle and cause something which has taken place in tile past; likewise, for things of the future, something which is future, and for things that are in the process of coming to be, one takes that which is coming to be, and for things that exist, one takes that which exists. However, when one syllogizes, “This has taken place; therefore this will be,” the middle taken is not of one genus, but one middle is prior and the other subsequent. Therefore, having posited what is prior, the subsequent does not follow of necessity in those cases in which the effect of causes can be impeded.
lib. 2 l. 10 n. 10 Deinde cum dicit: amplius enim neque etc., ponit aliam rationem, quae sumitur ex parte temporis medii; et dicit quod, sicut ex parte temporis absolute considerati manifestum est quod non potest syllogizari a priori ad posterius, nec secundum tempus determinatum, neque secundum tempus indeterminatum; ita etiam nec ex parte medii temporis contingit accipi aliquod determinatum aut indeterminatum, in quo scilicet possit concludi posterius a priori. Iam enim dictum est quod in toto tempore intermedio falsum est dicere id quod est posterius esse, quamvis id quod est prius iam praecesserit.	Then (95a39) he presents another argument which is based on the intervening time. And he says that just as on the part of time considered absolutely, it is obvious that one may not syllogize from what is prior to what is subsequent either according to a specified time or according to an unspecified time; so neither on the part of the intervening time is it possible to assume a specified or an unspecified time in which that which is subsequent can be concluded from what is prior. For it has already been established that during the entire intervening time it is false to say that the subsequent exists, even though that which is prior has already occurred.

Lecture 11 How a cause which is not simultaneous with its effect may be taken as a middle in demonstration

Latin	English
	Lecture 11 (95b1-37) HOW A CAUSE WHICH IS NOT SIMULTANEOUS WITH ITS EFFECT MAY BE TAKEN AS A MIDDLE IN DEMONSTRATION
lib. 2 l. 11 n. 1 Postquam philosophus quaesivit utrum in his quae non simul fiunt, posterius secundum continuitatem temporis sequatur ad prius; et interposuit quoddam necessarium, scilicet quod a priori ad posterius non syllogizatur; hic accedit ad determinandum quaestionem motam. Et circa hoc duo facit: primo, ostendit quomodo se habeant fieri et factum esse secundum temporis continuitatem; secundo, ostendit propositum; ibi: de hoc quidem igitur et cetera.	After stating the question whether in things that do not come to be simultaneously the subsequent according to temporal continuity follows the prior, and after interjecting something necessary, namely, that one may not syllogize from what is prior to what is subsequent, the Philosopher now undertakes to settle the question he raised. Concerning this he does two things. First, he shows how coming to be and having come to be are related according to continuity of time. Secondly, he proves his proposal (95b12).
lib. 2 l. 11 n. 2 Dicit ergo primo quod ad ostendendum propositum oportet speculari quid est coniungens, vel continuans factum esse ei quod est fieri, ut post unum continuo sequatur aliud. Et circa hoc dicit primo, manifestum esse quod fieri cum eo quod est factum esse, non est habitum, idest consequenter se habens. Dicuntur autem consequenter se habentia, quorum nihil est medium eiusdem generis, sicut duo milites in acie, vel duo clerici in choro. Habitum autem supra id quod est consequenter addit contactum, sicut dicitur in V Physicor. Sic ergo dicit quod fieri non potest esse consequenter se habens et contiguum cum hoc quod est factum esse.	He says therefore first (95b1), that in order to prove the proposal it is necessary to investigate what it is that joins or forms a continuity between a “having come to be” and a “coming to be,” so that one might follow the other without interruption. In regard to this he says first of all that it is obvious that a “coming to be” is not had, i.e., is not consecutive to a “having come to be.” (Those things are said to be consecutive which have no member of their genus between them; for example, two soldiers in a line or two clerics in their choir stalls. Had, however, adds the notion of contact to that which is consequent, as it is stated in Physics V). Thus, therefore, he is saying that a “coming to be” cannot be consecutive or contiguous to a “having come to be.”
Et hoc probat, quia neque etiam factum esse est contiguum, scilicet ut consequenter se habens cum alio factum esse; eo quod duo facta esse hoc modo se habent ut quaedam ultima et indivisibilia in tempore, sicut duo puncta in linea. Unde sicut duo puncta non sunt consequenter se habentia ad invicem, ita etiam neque duo facta esse; quia tam puncta quam facta esse sunt sicut indivisibilia, et talia non se habent consequenter in continuis, ut probatur in VI Physicor. Et quia duo facta esse non sunt consequenter se habentia, propter hoc etiam manifestum est quod fieri et factum esse non consequenter se habent. Fieri enim est divisibile, sicut et moveri; sed factum esse est indivisibile, sicut et punctus. Sicut igitur se habet linea ad punctum, sic se habet fieri ad factum esse. Sunt enim infinita facta esse in eo quod est fieri, sicut et infinita puncta sunt potentialiter in linea. Et haec est causa quare in linea non possunt accipi duo puncta consequenter se habentia, quia scilicet inter quaelibet duo puncta est accipere aliud punctum: et similiter inter quaelibet duo facta esse est accipere aliud. Unde duo facta esse non se habent consequenter.	Then he proves this, because not even a “having come to be” is contiguous in the sense of consecutive to any other “having come to be”: for two instances of “having come to be” are related in the way that two indivisible boundaries of time are related, or as two points in a line. Hence just as two points are not consecutive to one another, so neither are two instances of “having come to be”: for the points and the instances of “having come to be” exist as indivisibles, and such things are not consecutive in their continua, as is proved in Physics VI. And since two instances of “having come to be” are not consecutive, it is therefore obvious that a “coming to be” and a “having come to be” are not consecutive. For a “coming to be” is something divisible, just as a “being moved” is; but a “having come to be” is something indivisible, just as a point is. Therefore, as the line is to the point, so the “coming to be” is to the “having come to be.” For there is an infinitude of “having come to be’s,” just as there is potentially an infinitude of points in a line. And this is the cause why it is impossible to take two points that are consecutive in a line, namely, because between any two points there is still another point to be taken; likewise, between any two “having come to be’s” there is another to be taken. Hence two “having come to be’s” are not consecutive.
Et quia factum esse est terminus eius quod est fieri, sequitur consequenter quod nec fieri se habeat consequenter cum eo quod est factum esse: quia tunc duo facta esse se haberent consequenter ad invicem. Sed fieri immediate terminatur ad factum esse, sicut linea ad punctum. De his autem patet magis in universalibus de motu, idest in libro physicorum. Tractatur enim de his in sexto illius libri.	Furthermore, because a “having come to be” is the terminus of a “coming to be,” it follows that not even a “coming to be” is consecutive to a “having come to be”; otherwise two “having come to be’s” would be consecutive. Rather a “coming to be” is terminated immediately at a “having come to be,” as a line is terminated at a point. This matter is treated at greater length in the analysis of motion, i.e., Physics VI.
lib. 2 l. 11 n. 3 Deinde cum dicit: de hoc quidem igitur etc., ostendit secundum praedicta quomodo accipi possit immediate vel mediate effectus causae in his quae non simul sunt. Et primo, ostendit propositum; secundo, manifestat per exempla; ibi: habet autem sic se in operibus et cetera. Circa primum duo facit: primo, ostendit propositum in praeteritis; secundo, in futuris; ibi: similiter autem in eo quod erit et cetera. Circa primum duo facit: primo, ostendit propositum; secundo, excludit quamdam obviationem; ibi: aut semper intercidet et cetera.	Then (95b12) he shows in the light of the foregoing how the effect can be taken as being immediate or mediate to the cause in cases where they are not simultaneous. First, he proves his proposal. Secondly, he elucidates it with examples (95b31). Concerning the first he does two things. First, he shows his proposal in regard to the past. Secondly, in future things (95b25). Concerning the first he does two things. First, he shows his proposal. Secondly, he excludes an objection (95b23).
lib. 2 l. 11 n. 4 Dicit ergo primo quod ex praemissis accipi potest quomodo causa, quae accipitur ut medium in demonstratione, se habeat consequenter ei quod est in fieri vel generari: quia etiam in his demonstrationibus, quae syllogizant de his quae sunt in fieri, necesse est accipere esse aliquod medium et primum quae sint immediata; sicut si concludamus quod a factum est propter hoc quod c factum est; ita scilicet quod posterius factum sit c, et prius a. Puta si dicamus: iste sanatus est; ergo bibit medicinam: a priori enim non sequeretur syllogismus, ut supra dictum est; sed ipsum c accipitur ut principium, quamvis sit posterius in fieri, propter id quod est magis proximum ipsi nunc praesenti quam a.	He says, therefore first (95b12) that from what has been established it is possible to gather how a cause which is taken as a middle in demonstration may be consecutive to that which is in the process of becoming or of being generated: because even in these demonstrations which syllogize about things that are in a “coming to be,” it is necessary to admit a middle and a first which are immediate, as when we conclude that A has come to be because C has come to be, so long, namely, as C has come to be subsequently and A previously. For example, if we should say, “He has been cured; therefore he drank the medicine”: for the syllogism would not follow if we began with what is prior, as we have established above; but C is taken as a principle, although it is later in coming to be, owing to the fact that it is closer to the present now than A.
Praesens autem nunc est principium temporis, quia secundum ipsum distinguitur praeteritum et futurum, et sic oportet praesens nunc accipere ut principium notificandi temporis successionem. In praeteritis enim tanto aliquid est posterius in fieri, quanto est proximius in praesenti nunc; in futuris autem est e converso. Sicut igitur c accipitur ut principium syllogizandi, eo quod est posterius in fieri quam a, et propinquius praesenti nunc; ita et accipiamus d propinquius praesenti nunc quam c, et concludamus quod si factum est d, quod prius factum est c; puta si perfecit opus sani hominis, prius sanatus est.	But the present now is a principle of time because according to it the past and future are distinguished; hence it is necessary to take the present now as the principle for making known the succession of time. For in the realm of the past, something is more subsequent in becoming, future. Therefore, just as C is taken as the principle of syllogizing, since it is more subsequent in coming to be than A and closer to the present now, so we may take D as nearer to the present now than C, and conclude that if D has come to be, C came to be previously: for example, if he performs the tasks of a healthy man, then previous to that he was cured.
Possumus ergo concludere quod si factum est d, necesse est quod prius factum sit a: et accipitur pro causa id quod erat in medio, scilicet c. Facto enim d, necesse est quod prius factum fuerit c; et facto c, necesse est quod prius factum fuerit a; ergo facto d, necesse est quod prius factum fuerit a. Puta si hic homo iam perfecit opus sani hominis, sequitur quod prius fuerit sanatus; et si est sanatus, necesse est quod prius biberit medicinam. Sic igitur semper accipiendo medium, puta aliquid aliud inter c et a, sicut c acceptum est medium inter d et a, stabitur alicubi ad aliquod immediatum.	Therefore, we can conclude that if D has come to pass, it is necessary that A have previously come to pass; and we take as cause that which was in the interim, namely, C. For D having come to be, it is necessary that C previously have come to be; and C having come to be, it is necessary that A have previously come to be. Therefore, D having come to be, it is necessary that A have previously come to be. For example, if this person now accomplishes the tasks of a healthy man, it follows that previously he had been cured; and if he has been cured, it is necessary that previously he have drunk the medicine. Therefore, by always taking a middle in this way, for example, something else between C and A, as C was taken as middle between D and A, one will come to rest somewhere at something immediate.
lib. 2 l. 11 n. 5 Deinde cum dicit: aut semper intercidet propter etc., ponit quamdam obviationem. Potest enim aliquis dicere quod nunquam veniatur ad immediatum, sed semper erit accipere aliquod medium inter duo facta esse, propter hoc quod in ipso fieri sunt infinita facta esse, eo quod factum esse non consequenter se habet ad aliud factum esse, ut dictum est. Sed hanc obviationem excludit ipse, quia quamvis sint infinita facta esse in uno fieri, tamen necesse est incipere ab aliquo medio, scilicet ab ipso nunc, tanquam a primo: dictum est enim quod id quod est posterius, est principium syllogizandi; respectu autem omnium in praeterito factorum, postremum est ipsum praesens nunc; unde necesse est ipsum praesens nunc accipere ut primum et immediatum principium. Quodlibet autem aliorum factorum accipitur ut principium mediatum.	Then (95b23) he presents an objection. For someone can say that some thing immediate will never be reached, but it will always be necessary to take something between two “having come to be’s” on the ground that in every instance of coming to be there is an infinitude of “having come to be’s,” since one “having come to be” is not consecutive to another, as has been said. But he excludes this objection because although there is an infinitude of “having come to he’s” in one case of coming to be, nevertheless it is necessary to begin at some middle, namely, from a now as from something first: for it has been established that that which is subsequent is a principle of syllogizing. But in relation to all things that have come to be in the past, the latest is the present now; hence it is necessary to take the present now as the first and immediate principle. However, any other “having come to be” is taken as a mediate principle.
lib. 2 l. 11 n. 6 Deinde cum dicit: similiter autem est etc., manifestat idem in futuris; et dicit quod, sicut se habet in eo quod factum est, similiter se habet et in eo quod factum erit; quia si verum est quod erit d, necesse est quod prius verificetur quod sit a; et huiusmodi causa accipietur c, quod cadit medium inter d et a. Quia si erit d, necesse est quod prius erit c; et si erit c, necesse est quod prius sit futurum a.	Then (95b25) he shows the same for future things, saying that as the case was in that which has come to be, so it is in that which will have come to be: because if it is true that D will be, it is necessary that it previously be verified that A exists; and the cause of this will be taken to be C, which falls as middle between D and A. For if C will be, it is necessary that prior to it A will be.
Et similiter etiam in his potest fieri obiectio de infinita divisione futuri in instantia, vel motus in momenta; quia sicut in praeteritis, ita et in futuris non consequenter se habent indivisibilia. Et tamen hic etiam accipiendum est aliquid sicut immediatum principium, sicut dictum est in his quae facta sunt in praeterito. Licet enim non sit accipere duo facta esse se consequenter habentia, neque in praeterito neque in futuro, potest tamen accipi aliquid ultimum utrobique, et hoc accipietur ut principium immediatum.	In this case, too, the objection concerning the infinite division of the future into instants, or of motion into moments can be lodged: because, as in the case of past things, so also in future things, the indivisibles are not consecutive. Nevertheless here too, something must be taken as an immediate principle, as was done in things which came to be in the past. For although one cannot take two consecutive “having come to be’s” either in the past or in the future, nevertheless something terminal can be the closer it is to the present now; but the converse is true in regard to the taken in both, and this will be taken as the immediate principle.
lib. 2 l. 11 n. 7 Deinde cum dicit: habet autem sic se etc., manifestat quod dixerat per exempla; et dicit quod praedictus modus argumentandi potest considerari circa opera humana. Accipiamus enim factum esse domus tanquam quoddam postremum, ex quo concluditur sicut quoddam primum, quod necesse est lapides prius fuisse decisos; et accipiemus pro medio constructionem fundamenti: quia si domus facta est, necesse est quod prius sit factum fundamentum; et si factum est fundamentum, necesse est quod prius sint lapides decisi. Et quod dictum est in praeterito, accipiendum est etiam in futuro: puta si erit domus, necesse est quod prius futura sit decisio lapidum, et quod hoc demonstretur per medium, quod est constructio fundamenti.	Then (95b31) he elucidates what he had said with examples, saying that the manner of arguing employed above can be considered in regard, to human works. Thus, let us take the “having come to be” of a house as something terminal; from this it is concluded, as something first, that it is necessary that the stones have previously been cut; and we shall take as middle the laying of the foundation: because if the house has been constructed, it is necessary that previously the foundation has been laid; and if the foundation has been laid, it is necessary first that the stones have been cut. And what was taken in regard to the past must also be taken in regard to the future: for example, if a house will exist, it is necessary that first the cutting of the stones will occur, and that this be’ demonstrated through some middle, which is the laying of the foundation.

Lecture 12 How in things that come to be reciprocally, a cause which is not simultaneous with the effect is taken as middle in a demonstration

Latin	English
	Lecture 12 (95b38-96a20) HOW IN THINGS THAT COME TO BE RECIPROCALLY, A CAUSE WHICH IS NOT SIMULTANEOUS WITH THE EFFECT IS TAKEN AS MIDDLE IN A DEMONSTRATION HOW ONE DEMONSTRATES THROUGH CAUSE DIFFERENTLY, IN THINGS THAT OCCUR ALWAYS AND IN THINGS THAT OCCUR AS A GENERAL RULE
lib. 2 l. 12 n. 1 Postquam philosophus ostendit quomodo accipiendum sit medium quod est causa in his quae fiunt in rectum, hic ostendit quomodo debeat accipi in his quae fiunt secundum generationem circularem. Et primo, ostendit propositum; secundo, manifestat per exempla; ibi: in operibus autem videtur sic et cetera.	After showing how one must take the middle, which is the cause, in, things that come to be in a direct line, the Philosopher now shows hhow one should take it in the case of things that come to be in reciprocal generation. First, he proves his proposal. Secondly, he elucidates it with examples (96a2).
lib. 2 l. 12 n. 2 Circa primum considerandum est quod, quia motus caeli circularis causa est generationis in istis inferioribus, ideo dicitur in II de generatione, quod quaedam circulatio in generationibus invenitur, puta quod ex aqua generatur terra, et ex terra iterum aqua. Dicit ergo quod, quia videmus esse quamdam generationem in his quae circulo generantur, in his etiam contingit observari hoc quod supra dictum est, scilicet quod syllogizetur a posteriori, si hoc modo accipiantur termini demonstrationis, quod medium et extremi termini se invicem consequuntur: quia in his quae sic generantur, est quaedam conversio circularis, dum scilicet a primo generato devenitur ad ultimum, et ab ultimo reditur ad primum, non idem numero, sed idem specie, ut patet in II de generatione. Et ita non sequitur quod idem numero sit prius et posterius, effectus et causa.	In regard to the first it should be noted that because the circular movement of the heavens is the cause of generation in sublunar things, it is stated in On Generation II that a kind of circular reciprocity is found is generation in the sense that earth is generated from water, and water in turn from earth. He says therefore (95b38) that since we observe a certain pattern of generation in things that are generated circularly, it is possible in these cases also to follow what has been established above, namely, to syllogize from what is subsequent, provided that the terms of the demonstration are taken in such a way that middle and extremes follow one upon the other: because in the case of things that are generated in that way, there is a kind of circular conversion in the sense that one passes from the first thing to the last thing, and then a return is made from the last to the first; although these things are not numerically but specifically the same, as is explained in On Generation II. Hence it does not follow that the same numerical thing is prior and subsequent, or is cause and effect.
Et hoc ipsum competit processui demonstrationum, eo quod, ut in praecedentibus dictum est, quandoque conclusiones convertuntur, ut scilicet ex eis syllogizentur aliquae praemissarum; hoc enim est circulo demonstrare. Quod quamvis non competat si omnino sit unum et idem quod prius fuit conclusio, et postea est principium respectu eiusdem numero, ne sit idem notius et minus notum; si tamen non sit omnino idem, sicut accidit in his quae circulo generantur, nullum inconveniens est.	And this is suitable to the process of demonstrations, for, as has been established in the foregoing, whenever conclusions are converted, i.e., whenever some of the premises can be syllogized from them, this is a circular demonstration. And although this is not fitting if the very same thing which was first the conclusion is later the principle of the same numerical thing (otherwise the same thing would be at once better known and less known), nevertheless if they are not entirely the same, as happens in things that are circularly generated, there is nothing unfitting.
lib. 2 l. 12 n. 3 Deinde cum dicit: in operibus autem videtur sic etc., manifestat quod dixerat per exempla, et dicit quod in ipsis operibus naturae videtur sic evenire, quod sit quidam circularis processus. Quia si terra sit compluta, necesse est quod per actionem solis vapor ex ea resolvatur; quo resoluto et sursum elevato, necesse est quod generetur nubes; et hac generata, necesse est quod generetur aqua pluviae; qua generata, necesse est quod cadens super terram compluat eam. Et hoc est quod accipiebamus quasi primum: non tamen est eadem complutio terrae ad quam ultimo pervenitur, et a qua primo incipiebatur.	Then (96a2) he uses examples to elucidate what he has said, saying that a circular process is seen to occur in the works of nature. For if the earth is saturated with rain, it is necessary that the action of the sun release vapors from it; when these are released and borne aloft, it is necessary that clouds be formed; and after they are formed, it is necessary that rainwater be formed; and when this is formed, it is necessary that in falling upon the earth it saturate it. Now this saturation of the earth was the very thing we took as being first; however, it is not the same saturation as the one from which we first began.
Et sic manifestum est quod factus est quidam circuitus, inquantum uno eorum existente fit aliud, et illo existente fit aliquod aliud; quo existente reditur ad primum, non idem numero, sed idem specie. Iste tamen causarum circuitus inveniri non potest secundum ordinem qui invenitur in causis per se: sic enim necesse est pervenire ad unum primum in quolibet genere causarum, ut probatur in II Metaphys. Quod autem aqua generetur ex igne, et ignis iterato ex aqua, hoc non est per se, sed per accidens. Non enim ens per se generatur ut ex ente in actu, sed ex ente in potentia, ut dicitur in I Physicor. Procedendo ergo in causis per se non erit circulatio. Nam complutionis terrae causam agentem accipiemus calorem aeris, qui causatur ex sole, et non e converso; causam vero materialem aquam, cuius materia non est vapor, sed materia communis elementorum.	Thus it is clear that a cycle has been achieved in the sense that with one of them existing, another comes to be; and that other existing, still another comes to be; and that one existing, a return is made to the first, which is not numerically the same, but specifically the same. Yet this cycle of causes cannot be found according to the order which is found in pe se causes; for in per se causes it is necessary to reach some one thing which is first in each genus of causes as is proved in Metaphysics II. But the fact that water is generated from fire, and fire in turn from water, is not per se but per accidens. For being is generated per se not from actual being but from potential being, as it is stated in Physics I. Therefore, if we proceed from cause to cause in per se causes, there will not be a cycle. For we will accept as the efficient cause of the rain-soaked earth, the heat of the air which is caused by the sun, but not vice versa; but the material cause we take as water, whose matter is not vapor but the common matter of the elements.
lib. 2 l. 12 n. 4 Deinde cum dicit: sunt autem quaedam quae etc., ostendit qualiter diversimode demonstretur per causam in his quae sunt semper, et in his quae sunt ut frequenter. Et circa hoc tria facit: primo, proponit quod intendit; secundo, probat propositum; ibi: si enim a de b etc., tertio, epilogat quae dicta sunt; ibi: quomodo quidem igitur et cetera. Dicit ergo primo quod quaedam sunt quae universaliter fiunt, et quantum ad tempus, quia semper, et quantum ad subiectum, quia in omnibus, aut se habent, sicut immobilia, quibus non competit proprie fieri, aut fiunt, sicut mobilia quae semper eodem modo se habent, ut patet in motibus caelestibus. Quaedam vero non fiunt sicut semper, sed sicut frequenter. Et ponit de his exemplum. Sicut quod omnis homo masculus efficiatur quandoque barbatus, non accidit semper, sed sicut frequenter. Sicut igitur eorum quae sunt semper, oportet accipere medium quod est semper; ita et talium, quae sunt sicut frequenter, oportet accipere medium sicut frequenter.	Then (96a8) he shows how one demonstrates through the cause differently in things which occur always and in things which occur as a general rule. Concerning this he does three things. First, he proposes what he intends. Secondly, he proves what he has proposed (96a12). Thirdly, he sums up (96a20). He says therefore first (96a8) that there are some things which come to be universally both as to time, because always, and as to subject, because in all cases; either because they maintain themselves as unchangeable things which are not subject to coming to be, or because they come to be as changeable things which always follow a uniform pattern, as in the case of heavenly movements. Again, there are other things which do not occur in the sense of always, but as a general rule. An example of this is that every human male develops a beard as a general rule, although it does not occur always. Therefore, just as in the case of things that occur always, it is necessary to take a middle which is always, so in the case of things which occur as a general rule, it is necessary to take a middle that occurs as a general rule.
lib. 2 l. 12 n. 5 Deinde cum dicit: si enim a de b praedicatur etc., probat quod ad concludendum id quod est sicut frequenter, necesse sit accipere medium quod sit sicut frequenter. Detur enim oppositum, quod accipiatur medium quod sit universaliter et semper; puta si a, quae est maior extremitas, praedicetur universaliter de b, quod est medium, et b de c, quod est minor extremitas: ex necessitate sequitur quod a praedicetur de c universaliter, et quantum ad tempus et quantum ad subiectum, quod est semper et de omni praedicari. Unde idem nunc dicimus universaliter praedicari, quod praedicari de omni et semper.	Then (96a12) he proves that if one is to conclude to something that occurs as a general rule it is necessary to take a middle which occurs as a general rule. For if one were to assume the opposite by taking a middle which occurs universally and always; for example, if A, which is the major extreme, is predicated universally of B, which is the middle, and B of C, which is the minor extreme, then it follows of necessity that A is predicated universally of C both as to time and as to subject, which is the same as being predicated always and of each thing. Hence, we are now saying that for something to be predicated universally is the same as being predicated of all and always.
Sed suppositum erat quod a praedicaretur de c sicut frequenter. Necesse est ergo quod medium, quod est b, accipiatur sicut frequenter existens. Sic igitur patet quod possunt accipi quaedam immediata principia eorum quae sunt frequenter, ita quod ipsa principia sint aut fiant sicut frequenter. Huiusmodi tamen demonstrationes non faciunt simpliciter scire verum esse quod concluditur, sed secundum quid, scilicet quod sit verum ut in pluribus; et sic etiam principia quae assumuntur, veritatem habent. Unde huiusmodi scientiae deficiunt a scientiis, quae sunt de necessariis absolute, quantum ad certitudinem demonstrationis.	But it has been assumed that A is predicated of C as a general rule. Therefore, it is necessary that the middle, which is B, should be taken as existing as a general rule.Thus it is obvious that certain immediate principles of things which occur as a general rule can be taken, such that those principles exist or come to be as a general rule. Yet such demonstrations do not enable one to know that what is concluded is true absolutely but only in a qualified sense, namely, that it is true in the majority of cases. And this is the way that the principles which are taken possess truth. Hence sciences of this kind fall short of sciences which deal with things absolutely necessary, so far as the certitude of demonstration is concerned.
lib. 2 l. 12 n. 6 Deinde cum dicit: quomodo quidem igitur etc., epilogat ea quae dicta sunt; et dicit quod iam supra dictum est, quomodo quod quid est, quod est aliqualiter idem ei quod propter quid, assignatur inter terminos syllogisticos, dum ostensum est qualiter singula causarum genera, et in singulis diversitatibus rerum, sint media demonstrationum. Dictum est etiam qualiter eius quod quid est sit vel non sit demonstratio vel definitio.	Then (96a20) he sums up what has been said, saying that we have now established how the quod quid which is practically identical with the propter quid is assigned among syllogistic terms, inasmuch as we have shown how the several genera of causes are middles of demonstration according to the respective diversities of things. We have also shown in what sense there is or is not demonstration or definition of the quod quid.

Latin	English
	English translation by Fabian R. Larcher

Lecture 13 Characteristics which should be present in the items which constitute the definition signifying the essence of a thing

Latin	English
	Lecture 13 (96a22-b14) CHARACTERISTICS WHICH SHOULD BE PRESENT IN THE ITEMS WHICH CONSTITUTE THE DEFINITION SIGNIFYING THE ESSENCE OF A THING
lib. 2 l. 13 n. 1 Postquam philosophus ostendit qualiter quod quid est et propter quid se habeant ad demonstrationem, hic ostendit quomodo possint investigari: et primo, quomodo investigetur quod quid est; secundo, quomodo investigetur propter quid; ibi: ad habendum autem et cetera. Circa primum duo facit: primo, dicit de quo est intentio; secundo, exequitur propositum; ibi: eorum autem igitur quae insunt semper et cetera. Dicit ergo primo quod postquam dictum est qualiter quod quid est cognoscatur, et qualiter quod quid est vel propter quid accipiatur ut medium in demonstratione, nunc dicendum est quomodo oporteat investigare ea quae praedicantur in eo quod quid est.	After showing how the quod quid and propter quid are related to demonstration, the Philosopher now shows how they can be investigated. First, how the quod quid should be investigated. Secondly, how the propter quid ought to be investigated (98a1) [L. 17]. Concerning the first he does two things. First, he states his intention. Secondly, he pursues it (96a24). He says therefore first (96a22) that after stating how quod quid is recognized and how the quod quid or propter quid is taken as a middle in demonstration, we must now point out how to investigate those items which are predicated in quod quid.
lib. 2 l. 13 n. 2 Deinde cum dicit: eorum igitur quae insunt etc., ostendit propositum: et primo, manifestat qualia oporteat esse illa, quae accipiuntur ad constituendum quod quid est; secundo, quomodo sint inquirenda; ibi: congruum autem est cum totum aliquod et cetera. Circa primum tria facit: primo, praemittit quamdam divisionem; secundo, proponit qualia oporteat esse quae accipiuntur ad constituendum quod quid est; ibi: huiusmodi accipienda sunt etc.; tertio, probat; ibi: quoniam autem ostensum est et cetera.	Then (96a24) he states his proposal. First, he indicates what characteristics should be present in things which are accepted as constituting the quod quid. Secondly, how to investigate them (96b15) [L. 14]. Concerning the first he does three things. First, he presents a certain division. Secondly, he proposes what should be the characteristics of things which are taken as constituting quod quid (96a32). Thirdly, he proves (96b2).
lib. 2 l. 13 n. 3 Circa primum considerandum est quod ea quae praedicantur in eo quod quid est, oportet quod semper et universaliter praedicentur, ut supra habitum est: et ideo accipiens ea quae praedicantur de unoquoque ut semper, dicit quod inter ea quaedam inveniuntur quae extenduntur in plus quam id cui insunt; non tamen ita quod inveniantur extra genus illud. Et exponit quid sit esse in plus, et dicit quod in plus esse dicuntur quaecunque universaliter insunt alicui, non tamen ei soli, sed etiam alii. Datur autem per hoc intelligi aliud membrum oppositum, quia scilicet est aliquid quod extenditur in plus, et est extra genus. Et de hoc primo ponit exemplum, dicens quod est aliquid quod inest omni ternario, sed et non ternario inest; sicut patet de ipso ente communi, quod quidem universaliter inest non tantum Trinitati, sed etiam aliis; et non solum in genere numeri, sed etiam in his quae sunt extra genus numeri. Impar vero inest omni ternario, et est in plus, quia etiam inest ipsi quinario; non tamen invenitur extra genus ternarii, quod est numerus, quia etiam quinarius in genere numeri invenitur; nihil autem quod sit extra genus numeri potest dici impar.	In regard to the first (96a24) it should be noted that things predicated in quod quid must be such that they are predicated always and universally, as has been established above. Then taking those things which are predicated of each thing in the sense of always, he says that we find among them certain ones which apply to more than that in which they are present, but not to the extent of being found outside that genus. (He explains what is meant by apply to more, saying that those things are said to apply to more which are indeed universally present in something, but are not solely in it but in other things also). This would imply that there is another and opposite member which applies to more, but is outside the genus. He gives an example of the first one, saying that there is something which is present in every three, as well as in non-three’s, as is obviously true of being, which is universally present not only in three but in other things; and not only in the genus of number, but even in things outside the genus of number. Odd, however is found in every three and in more things, because it is found also in five’s; however, it is not found outside the genus of three, namely, number, because even five is in the genus of number. For nothing outside the genus of number can be called odd.
lib. 2 l. 13 n. 4 Deinde cum dicit: huiusmodi autem accipienda sunt etc., ostendit qualia debeant esse quae accipiuntur ad constituendum quod quid est. Et primo, proponit quod intendit; secundo, manifestat per exemplum; ibi: ut Trinitati omni et cetera. Dicit ergo primo quod ad manifestandum quod quid est accipienda sunt talia, quae quidem sunt semper et in plus, non tamen extra genus, usque ad talem terminum, ut primo quidem unumquodque quod accipitur sit in plus, omnia autem non sint in plus, sed convertantur cum re, cuius quaeritur quod quid est. Huius enim rationem necesse est significare quod quid est rei.	Then (96a32) he shows what should be the characteristics of things that are taken as constituting the quod quid. First, he proposes his intention. Secondly, he clarifies it with examples (96a34). He says therefore first (96a32) that in order to manifest the quod quid, we must take items which are both always and applicable to more (but not outside the genus), until the term is reached. And they should be so selected that each item when first taken should be applicable to more, but when all are taken together the combination does not apply to more, but is converted with the thing whose quod quid is sought. For the quod quid of a thing must signify its essence.
lib. 2 l. 13 n. 5 Deinde cum dicit: ut Trinitati omni inest numerus etc., manifestat quod dixerat per exemplum. Accipiamus enim ista quatuor, scilicet numerus, impar, primus utroque modo. Dupliciter enim dicitur aliquis numerus primus. Uno modo, quia non mensuratur aliquo alio numero, sicut per oppositum patet quod quaternarius non est numerus primus, quia mensuratur dualitate; ternarius autem est numerus primus, quia non mensuratur aliquo numero, sed sola unitate. Alio modo dicitur aliquis numerus primus, quia non componitur ex pluribus numeris; sicut patet per oppositum de septenario, qui primo modo est primus, non enim mensuratur nisi unitate; non autem est primus secundo modo, componitur enim ex ternario et quaternario: sed ternarius non componitur ex pluribus numeris, sed ex sola dualitate et unitate.	Then (96a34) he manifests what he had said with an example. Let us, therefore, take those four, namely, number, odd, and prime in both its senses. For there are two senses in which a number is said to be prime: in one way because it is not divided by any other number, as opposed to four, which is not a prime number, since it can be divided by two; three, however, is a prime number, because it is not divided by any other number except one. In another way a number is called prime because it is not composed of other numbers, as opposed to seven, which is prime in the first way, because it is not divided by any other number except one, but is not prime in the second way, for it is composed of three and four. Three, however, is not composed of several numbers, but only of the number two, and one.
Sic ergo patet quod quodlibet praedictorum quatuor convenit universaliter Trinitati, quodlibet autem eorum convenit etiam aliis in genere numeri. Nam hoc quod dicitur numerus et impar convenit omnibus numeris imparibus: ultimum autem, scilicet quod sit primus utroque modo, convenit etiam dualitati, quae nec mensuratur alio numero, nec componitur ex numeris, sed ex solis unitatibus: unde omnia ista simul iuncta significant quod quid est ternarius.	And so it is obvious that each of the four aforesaid notions belongs universally to every three, although each of them is also found in other things in the genus of number. For number and odd are found in all odd numbers; but the fourth, i.e, being prime in both ways, belongs also to two, which is neither divided by any other number nor composed of numbers, but only of units; hence, when they are all assembled they signify the quod quid of three.
lib. 2 l. 13 n. 6 Sed videtur quod non requiratur ad definitionem quod quaelibet particula sit in plus quam definitum. Dicit enim philosophus in VII Metaphys. quod quando pervenitur ad ultimas differentias, erunt aequales differentiae speciebus; non ergo oportet quod differentia sit in plus quam species. Quod etiam ratione videtur. Dicit enim philosophus in VIII Metaphys., quod ratio quae est ex differentiis, videtur esse speciei et actus, idest formae, quia, sicut ibidem dicitur, differentia respondet formae; cuiuslibet autem speciei est propria forma, quae nulli alii convenit. Videtur igitur quod differentia ultima non excedat speciem. Dicit etiam philosophus in VII Metaphys. quod nihil est aliud in definitione quam genus et differentiae, et quod possibile est definitionem ex duobus constitui, quorum unum sit genus, aliud differentia. Differentia autem non invenitur extra proprium genus, alioquin non esset divisiva generis per se, sed per accidens. Videtur ergo quod differentia non excedat speciem.	But the requirement that each particle of the definition apply to more than the definition seems superfluous. For the Philosopher says in Metaphysics VII that when the ultimate differences are reached, those differences will be equal to the species; therefore, it is not required that the difference apply to more things than the species does. This can also be proved with an argument. For the Philosopher says in Metaphysics VIII that a formality which is based on differences seems to be of the species and of the act, i.e., of the form; because, as he says in the same place, the difference corresponds to the form. But each species has its own appropriate form which belongs to no other species. Therefore, it seems that the ultimate difference does not exceed the species. Furthermore, the Philosopher in Metaphysics VII says that there is no more in a definition than genus and differences, and that it is possible for a definition to be formed of two things, one of which is a genus and the other a difference. But a difference cannot be found outside its appropriate genus; otherwise it would not divide the genus per se but per accidens. Therefore, it seems that the difference does not exceed the species.
lib. 2 l. 13 n. 7 Sed dicendum est quod si accipi posset differentia, quae notificaret ipsam formam substantialem speciei, nullo modo differentia ultima esset in plus quam species, ut rationes probant. Sed quia formae essentiales non sunt nobis per se notae, oportet quod manifestentur per aliqua accidentia, quae sunt signa illius formae, ut patet in VIII Metaphys. Non autem oportet accipere accidentia propria illius speciei, quia talia oportet per definitionem speciei demonstrari; sed oportet notificari formam speciei per aliqua accidentia communiora; et secundum hoc differentiae assumptae dicuntur quidem substantiales, in quantum inducuntur ad declarandum formam essentialem, sunt autem communiores specie, in quantum assumuntur ex aliquibus signis, quae consequuntur superiora genera.	But it should be answered that if one were able to discover the difference which would make known the substantial form of the species, then, as the arguments prove, the ultimate difference would not apply to more things than the species does. But because the essential forms are not known to us per se, they must be disclosed through certain accidents which are signs of that form, as is stated in Metaphysics VIII. However, one should not take the proper accidens of that species, because they are the ones that will be demonstrated by the definition of the species; rather the form of the species must be made known by certain accidents that are more common. Hence according to this, the differences which are used are indeed called substantial, inasmuch as they are adduced in order to declare the essential form; but they are more common than the species, inasmuch as they are taken from signs which follow upon higher genera.
lib. 2 l. 13 n. 8 Deinde cum dicit: quoniam autem ostensum est etc., ostendit quod supra dixerat: et primo, quod oporteat praedicta universaliter et ex necessitate praedicari de ternario; secundo, quod ex praedictis constituatur ipsa essentia ternarii; ibi: quod autem substantia ex his et cetera. Dicit ergo primo quod quia superius ostensum est quod ea quae praedicantur in eo quod quid est ex necessitate insunt; quaecunque autem ex necessitate insunt, universaliter praedicantur; necesse est quod sive de ternario sive de quocunque alio accipiantur praedicto modo ea quae praedicantur in eo quod quid, quod ex necessitate et universaliter praedicentur.	Then (96b2) he explains what he had said above. First, the statement that the items mentioned above should be predicated universally and necessarily of three. Secondly, that the very essence of three is constituted by those items (96b6). He says therefore first (96b2) that since it has been established above that items which are predicated in quod quid are present of necessity, and whatever is present of necessity is predicated universally, it follows that whether those items which are taken in the manner above indicated be predicated as quod quid of three or of any other thing, it is necessary that they be predicated necessarily and universally.
lib. 2 l. 13 n. 9 Deinde cum dicit: quod autem substantia etc., ostendit quod ex his quae praedicto modo accipiuntur, constituatur essentia ternarii, vel cuiuscunque alterius; quia necesse est, si hoc quod supra positum est non esset ipsa substantia ternarii, cum praedicetur in eo quod quid est, quod esset quoddam genus, vel nominatum vel innominatum. Non enim cuilibet rationi est nomen impositum: et inde est quod multa sunt innominata tam in generibus quam in speciebus. Ideo autem oportet quod praedicta ratio sit genus ternarii, si non significet essentiam eius, quia omne quod praedicatur in quid, aut est genus aut definitio significans essentiam. Non est autem possibile quod sit genus, quia sequeretur quod esset in plus quam ternarius: hoc enim supponimus esse genus, cuius potentia sub se plures species continet. Habitum est autem quod praedicta ratio non convenit nisi atomis, idest individuis, sub ternario contentis. Relinquitur ergo quod praedicta ratio sit definitio significans essentiam ternarii. Haec enim supponitur esse essentia uniuscuiusque, quae invenitur in individuis illius speciei finaliter, secundum praedictum modum praedicationis. Et sicut dictum est de ternario, ita etiam est intelligendum de quibuscunque aliis, quibus demonstretur aliquid esse idem per modum praedictum.	Then (96b6) he shows that from things which are taken in the abovementioned way the essence of three or of anything else is constituted; for it is necessary, if the items mentioned above are not the substance of three, that they be its genus, either named or unnamed, since they are predicated in quod quid. For not every formality has a name. That is why there are many genera and species without names. However, the reason why the above formality is the genus of three, if it does not signify its essence, is that whatever is predicated in quid is either the genus or the definition signifying the essence. Yet it cannot be the genus; otherwise it would apply to more things than three’s: for we assume a genus to be something which potentially contains several species under it. But we have established that the aforesaid formality applies only to the atoms, i.e., to the individuals contained under three. What remains, therefore, is that the formality in question is the definition signifying the essence of three. For the essence of a thing is supposed to be that which is found in the individuals of that species ultimately, according to the manner of predication described above. And what has been said of three is also understood of any other things regarding which something is demonstrated to be the same in the manner indicated above.

Lecture 14 Dividing the genus to investigate which items should be put in a definition

Latin	English
	Lecture 14 (96b15-97a6) DIVIDING THE GENUS TO INVESTIGATE WHICH ITEMS SHOULD BE PUT IN A DEFINITION
lib. 2 l. 14 n. 1 Postquam philosophus ostendit qualia oportet esse ea quae constituunt definitionem significantem essentiam rei, hic ostendit qualiter debeant investigari. Et circa hoc duo facit: primo, proponit modum maxime convenientem ad investigandum ea quae sunt in definitione ponenda, scilicet per divisionem generis; secundo, ponit quemdam alium modum per similia et differentia; ibi: quaerere autem oportet et cetera. Circa primum duo facit: primo, ostendit quod oportet uti divisione generis ad investigandum particulas definitionis; secundo, ostendit quid oporteat in tali investigatione observari; ibi: ad consequendum autem terminum et cetera. Circa primum duo facit: primo, ostendit veritatem; secundo, excludit errorem; ibi: nihil autem oportet dividentem et cetera. Circa primum tria facit: primo, ostendit qualiter per divisionem generis investigentur definitionis particulae; secundo, quomodo processus divisionis sit utilis ad propositum; ibi: divisiones autem quae sunt etc.; tertio, quomodo sunt cavenda ea, quae circa hunc processum defectum inducere possunt; ibi: differt autem et cetera. Circa primum duo facit: primo, ostendit quod oportet uti divisione generis ad definiendum; secundo, quomodo oportet accipere differentias; ibi: post autem accepto et cetera.	After showing what should be the characteristics of the items which constitute the definition signifying the essence of a thing, the Philosopher now shows how they should be investigated. Concerning this he does two things. First, he proposes the most suitable method of investigating the items to be put in the definition, namely, by division of the genus. Secondly, he sets forth another method, namely, by similarities and differences (97b7) [L. 16]. Concerning the first he does two things. First, he shows that one should employ division of the genus for investigating the particles of the definition. Secondly, he shows what to look for in such an investigation (97a23) [L. 15]. In regard to the first he does two things. First, he shows the truth. Secondly, he excludes an error (97a6) [L. 151. Concerning the first he does three things. First, he shows how the particles of a definition are investigated by the method of dividing the genus. Secondly, how the process of division is useful for this task (96b25). Thirdly, how to avoid pitfalls which can invalidate this process (96b30). Concerning the first he does two things. First, he shows that one should employ division of the genus for defining. Secondly, how one should take the differences (96b18).
lib. 2 l. 14 n. 2 Dicit ergo primo quod cum aliquis vult negotiari, ad definiendum, aliquod totum, idest universale, congruum est ut primo dividat genus in primas partes illius generis, quae sunt indivisibiles secundum speciem, puta quod dividat numerum in binarium et ternarium: et hac divisione praemissa, per quam cognoscitur genus, tentet postea accipere definitionem singularum specierum; sicut etiam fit in aliis, puta in recta linea et in circulo et in recto angulo. Omnia enim haec congrue definiuntur, praemissa divisione generis.	He says therefore first (96b15) that when someone wishes to deal with some whole, i.e., a universal, in order to define it, it is recommended that he first divide the genus into the first parts of that genus, i.e., those that are not further divisible into species; for example, he should divide number into two and three. Having accomplished this division through which the genus is known, he should then try to obtain the definition of each species as is done in other matters, say in the matter of straight line and circle and right angle. For all these are fittingly defined after one has divided the genus.
lib. 2 l. 14 n. 3 Deinde cum dicit: post haec autem accipientem etc., ostendit qualiter sint accipiendae differentiae; et dicit quod postquam acceperimus per divisionem generis in species quid sit genus, puta utrum sit in genere qualitatis vel quantitatis, oportet ad investigandum differentias considerare proprias passiones, quae, sicut dictum est, sunt signa manifestantia formas proprias specierum. Et hoc oportet primum facere per aliqua communia. Si enim nos congregemus accidentia ex generibus communioribus (quae hic dicuntur indivisibilia, quia non resolvuntur in aliqua priora genera), statim ex definitionibus eorum erunt manifesta ea quae quaerimus. Oportet enim omnium definitionum esse principium id quod simplex est, idest genus commune: et huiusmodi simplicibus solum per se insunt accidentia, quae communiter inveniuntur in multis; omnibus autem aliis conveniunt secundum illa. Sicut album et nigrum per se quidem conveniunt corpori terminato, et secundum hoc commune conveniunt et homini et equo et quibuscunque aliis. Unde si oporteret accipere definitionem alicuius, cui universaliter conveniret album, puta definitionem nivis, oporteret recurrere ad genus communius, quod est corpus terminatum, et ex eo investigare causam albedinis; et secundum hoc ostenderetur nobis quare nix universaliter sit alba. Et illa causa poterit pertinere ad quod quid est nivis; puta inspissatio humidi, quae facit humidum terminari cum conservatione lucis.	Then (96b18) he shows how to obtain the differences, saying that after we have learned what the genus is by dividing the genus into its species, for example, whether it is in the genus of quality or quantity, the next step is to investigate the differences by considering the proper attributes which, as has been said, are signs manifesting the forms proper to the species. And this should first be done by means of certain common items. For if we assemble the accidents from the more common genera (which he here calls indivisibles, because they are not resolved into prior genera), then from their definitions the things we are searching for will be immediately obvious. For “the basic element of all definitions must be something simple,” i.e., a common genus; furthermore, it is only in such simple things that the accidents inhere per se which are commonly found in many, but they are found in all other things in virtue of those simple genera. For example, black and white belong per se to terminated body; and in virtue of this common characteristic they belong also to man and horse and other things. Hence if one is to obtain the definition of something to which white belongs universally, say the definition of snow, he must have recourse to the more common genus, such as terminated body, and obtain from it the cause of whiteness; and according to this we would learn why snow is white universally. And that cause could pertain to the quod quid of snow: for example, the solidifying of a moist element which makes it be terminated, some light being preserved.
lib. 2 l. 14 n. 4 Deinde cum dicit: divisiones autem quae sunt etc., ostendit quomodo praedictus processus conferat ad definitiones; et dicit quod ad hoc quod aliquis praedicto modo procedat ad definiendum, scilicet dividendo genus in species, utile est quod homo accipiat divisionem generis per differentias. Sed tamen quomodo per hoc manifestetur quod quid est, dictum est in praecedentibus. Sunt quidem utiles praedictae divisiones ad accipiendum quod quid est sic solum, sicut dictum est; sed ad syllogizandum quod quid est nihil videntur facere, ut prius dictum est. Sed videtur quod dividentes statim accipiant omnia non syllogizata, sicut si a principio aliquis accepisset, antequam divideret.	Then (96b25) he shows how the above method is useful in definitions. And he says that when someone seeks to define according to the above method, i.e., by dividing the genus into species, the benefit it confers is that it accomplishes the division of the genus through differences. How this method reveals the quod quid has been indicated above. Furthermore, these divisions are useful for achieving the quod quid solely in the manner described above; they seem to contribute nothing to the syllogizing of the quod quid, as we said earlier. Rather it seems that upon dividing, one immediately obtains everything without syllogizing, as though he knew them from the beginning before he divided.
lib. 2 l. 14 n. 5 Deinde cum dicit: differt autem aliquid prius etc., ostendit quid oporteat cavere, ne circa praedictum processum defectus accidat. Et circa hoc duo facit: primo, ostendit quod oportet cavere inordinationem: secundo, quod oportet cavere diminutionem; ibi: amplius autem ad nil relinquendum et cetera. Dicit ergo primo quod multum differt quid prius et quid posterius praedicetur inter ea quae ponuntur in definitione. Potest enim uno modo sic dici, quod homo est animal mansuetum bipes; alio modo potest aliter ordinari, ut dicatur quod homo est bipes animal mansuetum. Et quod hoc differat ad definiendum patet per hoc, quod oportet omne quod definitur constitui ex duobus, scilicet ex genere et differentia. Sic igitur si mansuetum accipitur ut differentia animalis, oportet quod animal mansuetum sit aliquid unum quod accipiatur ut genus, ex quo et alia differentia quae est bipes, constituatur homo. Et eadem ratio est de quocunque alio quod fit unum ex pluribus per se, et non per accidens.	Then (96b30) he shows what to avoid if this method is not to fail. Concerning this he does two things. First, he shows that one must avoid improper order. Secondly, one must avoid diminution (96b35). He says therefore first (96b30) that it makes a great difference, when arranging the items present in a definition, which items are mentioned first and which are mentioned later. For it is possible to state that man is a gentle animal which is two-legged, or to state that man is a two-legged animal which is gentle. That the order of terms does make a difference in defining is clear from the fact that anything which is defined should be composed of two things, namely, a genus and a difference. Therefore, if “gentle” is taken as a difference of animal, it is required that “gentle animal” be some one thing which can be taken as a genus from which, with the addition of the difference “two-legged,” man is constituted. And the same reason holds for anything else which is formed from several things into a unit which is per se and not per accidens.
Sicut igitur differt quod accipiatur hoc vel illud pro genere vel differentia, aut quod accipiatur aliquid ut est differentia constitutiva generis et divisiva eiusdem; ita differt ad definiendum quod sic vel aliter partes definitionis ordinentur. Si enim dicam quod homo est animal mansuetum bipes, accipietur animal ut genus, mansuetum autem ut differentia constitutiva eius, bipes autem ut differentia divisiva ipsius. E converso autem erit si dicatur quod homo est animal bipes mansuetum. Quia igitur differentia ordinis facit differentiam in quod quid est, consequens est quod ille qui dividit, non solum supponat ea quae accipiuntur ad definiendum, sed etiam petat ordinem eorumdem. Et sic manifestum est quod definitio non syllogizat quod quid est.	Therefore, just as it does make a difference whether this or that be taken for the genus or the difference, or whether something is taken as a difference constituting the genus or as dividing it, so it makes a difference in defining just how the parts of the definition are ordered. For if I say that man is a two-legged gentle animal, “animal” will be taken as the genus, “gentle” as the difference constituting a genus, and “two-legged” as the difference dividing it. It will be the opposite if I say that man is a gentle two-legged animal. Therefore, since a variation in order makes a difference in quod quid, the consequence is that one who divides should not only suppose the things which are taken for defining, but should take care about the ordering of those things. And so it is clear that a definition does not syllogize the quod quid.
lib. 2 l. 14 n. 6 Deinde cum dicit: amplius autem ad nil relinquendum etc., docet cavere diminutionem, ostendens quomodo fieri possit ut nil praetermittatur eorum quae requiruntur ad quod quid est; et dicit quod hoc contingit fieri solum isto modo quo dicetur. Ad cuius evidentiam considerandum est, quod omnes differentiae superiorum generum pertinent ad quod quid est alicuius speciei. Nam inferius genus constituitur per differentiam divisivam superioris generis. Ad vitandum ergo diminutionem, oportet quod nulla huiusmodi differentiarum praetermittatur. Praetermittitur autem si aliquis, accepto supremo genere, accipiat consequenter aliquam differentiam divisivam non quidem ipsius supremi generis, sed alicuius inferioris. Quod quidem hoc modo cognosci potest: quia cum animal accipiatur aliquod supremum genus, si postea aliquis accipiat divisionem alicuius de inferioribus generibus, non totum quod continetur sub genere superiori cadet sub illa divisione.	Then (96b35) he teaches that one should avoid diminution, pointing out how to make certain that nothing required for the quod quid be omitted. And he says that the only way this can be avoided is by following the method he will indicate. To understand this it should be noted that all the differences of higher genera pertain to the quod quid of some species. For the lower genus is constituted by the difference which divides the higher genus. Therefore, to avoid diminution it is necessary that none of these differences be overlooked. But they are overlooked if someone, after taking the supreme genus, were to take a difference which divides not that supreme genus but some lower genus. But this can be recognized in the following way: when animal is taken as a supreme genus, if someone then takes the division of something pertaining to lower genera, not everything which is contained under the higher genus will fall into that division.
Et ponit ad hoc exemplum: sicut non omne animal est vel totalum, vel divisum pennis. Dicitur autem animal totalum, quod habet totas alas integras et continuas, sicut vespertilio; divisum autem pennis dicitur animal, cuius alae distinguuntur per diversas pennas, sicut accipitris vel corvi. Animali autem non habenti alas neutrum horum convenit; sed omne animal volatile continetur sub altera harum differentiarum, quia secundum praedictas differentias dividitur hoc genus quod est animal volatile. Sed prima et immediata differentia animalis attenditur ex hoc quod omne animal cadit sub divisione. Et ita est etiam de omnibus aliis generibus, sive accipiamus genera quae sunt extrinseca ab animali, sicut lapis et planta, sive illa quae sub animali continentur, sicut avis et piscis. Prima tamen differentia avis attenditur secundum differentiam in quam incidit omnis avis: et eadem ratio est de pisce.	As an example of this he says: for example, not every animal is either whole-winged or possessed of divided wings. (An animal is said to be whole-winged if its wings are each a continuous whole, as in a bat; but an animal is said to be possessed of divided wings if its wings are composed of distinct feathers, as in a hawk or raven). But neither of these belongs to a non-winged animal. However, any animal that flies is contained under one or other of these differences, because it is according to the above differences that this genus, flying animal, is divided. But the first and immediate difference of animal is such that every animal falls under the division. And the same applies to all other genera, whether we are dealing with genera extrinsic to animal, such as stone and plant, or those which are contained under animal, such as bird and fish. Yet the first difference of bird is such that every bird is included; and the same is true of fish.
Concludit ergo quod si aliquis sic procedat in dividendo, quod scilicet totum divisum contineatur sub partibus divisionis, poterit homo cognoscere quod nil est relictum de his quae sunt necessaria ad definiendum. Si autem aliter procedatur, necesse est quod aliqua relinquantur, et quod homo non cognoscat se integraliter definisse.	He concludes, therefore, that if someone proceeds to divide according to this method, namely, that the totality which is divided is contained under the parts of the division, he will be able to know that nothing necessary for defining has been omitted. But if he proceeds some other way, he is bound to omit something; and he will not be sure that he has defined integrally.

Lecture 15 Two errors are excluded. What is really required for constituting a definition according to the method of division?

Latin	English
	Lecture 15 (97a6-b6) TWO ERRORS ARE EXCLUDED.-WHAT IS REALLY REQUIRED FOR CONSTITUTING A DEFINITION ACCORDING TO THE METHOD OF DIVISION?
lib. 2 l. 15 n. 1 Postquam philosophus ostendit veritatem circa divisionem generis, quae assumitur ad definiendum, hic excludit duos errores. Secundum, ibi: omne autem incidere et cetera. Circa primum tria facit. Primo proponit exclusionem erroris: et dicit quod non est necessarium quod ille qui dividendo definit, sciat omnia quae sunt in mundo.	After presenting the truth concerning the division of the genus which is used in defining, the Philosopher here excludes two errors. In regard to the first one he does three things: First (97a6) he excludes the error and says that it is not necessary that one who defines by dividing should know all the things which exist in the world.
lib. 2 l. 15 n. 2 Secundo, ibi: et tamen impossibile quidam dicunt etc., narrat opinionem errantium. Dicebant enim quidam, quod non potest cognosci differentia alicuius ad omnia alia entia, nisi omnia alia entia cognoscantur, ut patet in aliquibus duobus, quorum differentiam cognoscere non possumus nisi utrumque cognoscamus. Addebant autem quod non est possibile quod aliquid sciatur quid est, nisi cognoscatur differentia eius ad omnia alia. Id enim a quo aliquid non differt est idem ei: illud autem a quo differt est alterum ab ipso. Non autem possumus scire quid sit unumquodque, nisi sciamus quid sit idem ei, et quid alterum ab eo. Et secundum hoc concludebant quod non potest aliquid cognosci nisi omnia cognoscantur.	Secondly (97a7) he sets forth the opinion of those who make this error. For some have said that it is not possible to know the difference between one thing and everything else, unless everything else is known, as is plain in regard to any two given things, whose difference we cannot know unless we know both things. However, they added that the quid est of something cannot be known, unless the difference between it and everything else is known. For that wherein something is not different is identical with it, whereas that by which something differs is other than it. But we cannot know what a thing is, unless we know what is the same as it and what is other than it. According to this, therefore, they concluded that something cannot be known unless everything is known.
lib. 2 l. 15 n. 3 Tertio, ibi: primum quidem igitur etc., improbat quod dictum est dupliciter. Et primo quidem interimit hoc quod dictum est, quod illud a quo aliquid differt, est alterum. Loquimur enim nunc de eodem et de altero secundum essentiam, quam significat definitio. Manifestum est autem quod etiam in eadem specie sunt multae differentiae accidentales, quae non diversificant substantiam speciei, quam significat definitio, nec per se insunt. Unde consequens est quod non omnis differentia facit talem alteritatem, quam necessarium sit cognoscere ad definiendum.	Thirdly (97a11) he disproves what they say in two ways. First, he destroys the statement according to which it is said that that by which something differs is something other. For we are now speaking about what is the same and what is other according to the essence which the definition signifies. But it is obvious that even in the same species there are many accidental differences which neither diversify the substance of the species which the definition signifies, nor are in it per se. Hence it follows that not every difference makes something other in such a way that it must be known if one is to define.
lib. 2 l. 15 n. 4 Secundo, ibi: postea cum accipiat opposita etc., improbat quae dicta sunt alio modo. Cum enim ille qui vult definire dividendo, accipiat oppositas differentias hoc modo, quod omne quod continetur sub diviso, cadat sub hoc membro divisionis vel sub illo, et accipiat sub altero membrorum illud cuius definitio quaeritur, si hoc quod intendit definire, cognoscat sub illo membro divisionis contineri; non differt ad propositum utrum sciat vel nesciat de quibuscunque aliis rebus praedicentur oppositae differentiae. Puta si dividam animal per rationale et irrationale, et accipiam propositum sic hominem contineri sub rationali, non requiritur quod sciam de quibus irrationale praedicetur, nec qualiter illa ad invicem differant. Manifestum est enim quod si aliquis sic procedat, scilicet dividendo genus per primas differentias eius, et accipiendo propositum sub altero membro, dividens quousque perveniatur in illa quae ulterius dividi non possunt essentialibus differentiis; sic procedens habebit definitionem substantiae, quam quaerebat.	Secondly (97a13), he disproves it another way. For since one who proposes to define by dividing must take opposing differences in such a way that everything contained under the divided whole falls under this member or that member of the division, and must subsume under one or the other of the members that whose definition is sought (if he knows that the thing he intends to define is contained under that member of the division), then it makes no difference, so far as his intent is concerned, whether he knows or does not know the things of which the opposing differences might be predicated. For example, if I divide animal into rational and irrational, and assume that man is contained under animal in the way we have proposed, it is not required that I know the things of which irrational is predicated or how they differ from one another. For it is obvious that if someone proceeds in this way, namely, by dividing the genus into its first differences and taking the definitum [thing being defined] as subsumed under one of the members and then dividing until certain items are reached that cannot be further divided by essential differences, then by proceeding in this manner he will have the definition of the substance which he was seeking.
Decipiebantur ergo praedicti homines ex eo quod non distinguebant inter cognoscere aliquid in communi et in speciali. Oportet enim quod quicunque scit quid est aliquid, cognoscat omnia alia in communi, non autem in speciali. Puta qui scit quid est homo, oportet quod sciat hominem per hoc quod est animal, distingui ab omnibus quae non sunt animalia; et per hoc quod est rationale, distingui ab omnibus quae non sunt rationalia. Non enim oportet quod illa cognoscat, nisi secundum hoc commune quod est non animal, vel irrationale.	Therefore, the persons mentioned above were deluded for failing to distinguish between something in common and in detail. For it is required of one who knows what something is, that he know all things in common but not in detail. For example, one who knows what man is must know that it is through being an animal that man is distinguished from all things that are not animals, and through being rational that man is distinguished from all things that are not rational. But it is not required that he know anything more about these others than is included in the general notion of non-animal or irrational.
lib. 2 l. 15 n. 5 Deinde cum dicit: omne autem incidere etc., excludit secundum errorem. Posset enim aliquis credere quod quicunque utitur divisione ad definiendum, indigeat petere quod totum divisum contineatur sub membris divisionis; sed ipse dicit quod hoc non est necessarium, si opposita, per quae fit divisio, sint immediata; quia secundum hoc necessarium est quod totum divisum sub altero oppositorum contineatur, dum tamen accipiantur primae differentiae alicuius generis. Differentiae enim quae sunt immediatae si comparentur ad genus inferius, non sunt immediatae si comparentur ad genus superius. Sicut par et impar sunt immediata si comparentur ad numerum, cuius sunt propriae differentiae; non autem si comparentur ad quantitatem.	Then (97a19) he excludes the second error. For someone might believe that whoever uses division for defining must assume that the entire whole is contained under the members of the division. But he says that this is not necessary, if the opposites through which the division is made are immediate; because the divided whole is necessarily contained under one of the opposites, provided the first differences of the genus were taken. For differences which are immediate when compared to a lower genus are not immediate if compared to a higher genus. For example, even and odd are immediate if compared to number of which they are proper differences, but not if they are compared to quantity.
lib. 2 l. 15 n. 6 Deinde cum dicit: ad construendum autem terminum etc., postquam exclusit ea quae non requiruntur ad divisiones definiti, hic ostendit quae secundum rei veritatem requirantur. Et primo, proponit quod intendit; secundo, manifestat propositum; ibi: est autem horum unum. Dicit ergo primo quod ad hoc quod aliquis constituat terminum, idest definitionem, per viam divisionis, tria oportet considerare: quorum primum est, ut ea quae accipiuntur, praedicentur in eo quod quid est; secundum est, ut ordinetur quid sit primum et quid secundum; tertium est, quod accipiantur omnia quae pertinent ad quod quid est, et nihil eorum praetermittatur.	Then (97a23), after rejecting things which are not required in the divisions of the definitum, he shows what is really required. First, he proposes what he intends. Secondly, he manifests his proposal (97a25). He says therefore first (97a23) that in order to achieve a term, i.e., a, definition, by the method of division three things must be observed: first, that the things which are taken be predicated in quod quid; secondly, that they be arranged according to what is first and what is second; thirdly, that everything taken pertain to the quod quid and that nothing be omitted.
lib. 2 l. 15 n. 7 Deinde cum dicit: est autem horum unum etc., manifestat propositum. Et primo, ostendit quomodo tria praedicta possunt observari; secundo, ostendit quod praedicta tria observata sufficiant; ibi: manifestum est autem et cetera. Circa primum tria facit. Primo ostendit quomodo observetur primum: et dicit quod unum horum (scilicet quod accipiantur ea quae praedicantur in eo quod quid est) observatur, primo quidem per hoc quod homo potest inducere syllogismos quod id quod assumitur insit, sicut cum disputatur ad problema de accidente; secundo, ut ostendatur quod praedicatur in eo quod quid, per ea quibus disputatur ad problema de genere.	Then (97a25) he manifests his proposal. First, he shows how these three rules can be observed. Secondly, he shows that it is enough to observe those three rules (97b1). In regard to the first point he does three things. First (97a25), he shows how the first rule is observed, saying that this one (namely, that one take things which are predicated in quod quid) is observed, first of all, by the fact that a person can form syllogisms to show that what is assumed is in the thing (as is done when there is dispute about whether something is an accident); secondly, to show that it is predicated in quod quid (as is done when there is dispute about a genus).
lib. 2 l. 15 n. 8 Secundo, ibi: ordinare autem sicut oportet etc., manifestat quomodo observetur secundum, scilicet debita ordinatio partium; et dicit quod tunc ordinantur partes definitionis sicut oportet, si aliquis primo accipiat id quod est primum; et hoc erit si aliquis primo accipiat id quod consequitur ad alia posterius accepta, et non e converso. Hoc enim est communius et prius. Necesse est autem aliquid huiusmodi accipi in definitione tanquam genus, puta cum dicitur quod homo est animal gressibile bipes. Si enim est gressibile bipes, est animal, sed non e converso. Cum ergo iam acceperimus animal tanquam primum, idem modus observandus est in ordinatione inferiorum. Accipietur enim quasi secundum in definitione illud quod secundum rationem praemissam erit primum inter omnia sequentia; et similiter accipietur tertium id quod est primum respectu habitorum, idest consequentium. Semper enim, remoto superiori, illud quod est habitum, idest immediate consequens, erit primum omnium aliorum. Et ita est etiam in omnibus aliis, puta in quarto et in quinto, si tot oporteat partes definitionis esse.	Secondly (97a28), he shows how the second rule is observed, namely, that there be a correct ordering of the parts. And he says that the parts of a definition are arranged as they should, if one takes what is first—and he will do this, if he first takes that which is implied by the other things that are taken later, and not conversely. For this is more common and prior. But such a thing must be taken in the definition as a genus, as when it is stated that man is an animal, two-legged and walking. For if he is a two-legged walker, he is an animal; but not vice versa. Therefore, when I have taken animal as first, the same method must be observed in arranging the other items. For the second item to be employed in the definition will be that which according to the foregoing description will be first among all the others; likewise, the third item to be taken will be that which is first in respect of the items had, i.e., following. For it will always turn out that when the more general item has been removed, that which is had, i.e., that which immediately follows, will be true in regard to all the other items, say a fourth and a fifth, if that many parts are needed for the definition.
lib. 2 l. 15 n. 9 Tertio, ibi: quod autem haec omnia sint etc., manifestat, qualiter possit tertium observari. Et dicit quod manifestum erit omnia quae pertinent ad quod quid est accipi in definitione secundum modum supra dictum, ex hoc scilicet quod dividendo aliquod genus accipimus primas eius differentias, sub quibus divisum universaliter continetur; sicut quod omne animal est hoc vel illud, puta rationale vel irrationale, et accipimus quod illud quod intendimus definire, est hoc, puta rationale. Et iterum accipiemus hoc totum, scilicet animal rationale, et dividemus ipsum per differentias proprias; sed quando iam devenerimus ad ultimam differentiam, iam non erit dividere per alias differentias specificas: sed statim ultima differentia addita, hoc, cuius definitio quaeritur, in nullo differet specie a simul toto, idest a ratione congregata ab omnibus partibus acceptis; sicut homo non differet specie ab aliquo eorum de quibus praedicatur animal rationale mortale.	Thirdly (9704), he shows how the third rule can be observed. And he says that it will be obvious that all items pertaining to the quod quid are present in the definition according to the aforesaid method, because when we divide the genus, we take its first differences, under which the divisum is universally contained; for example, that every animal is this or that, i.e., rational or irrational, and we assume that what we intend to define is this, i.e., rational. And again we take this whole, namely, rational animal, and divide it by its proper differences; but when we arrive at the ultimate difference, it will be impossible to divide by other specific differences, but as soon as the ultimate difference is added, the thing whose definition is being sought will differ in no way from the assembled whole, i.e., from the description formed by all the parts that were taken. Thus, man does not differ specifically from any of those of whom rational mortal animal is predicated.
lib. 2 l. 15 n. 10 Deinde cum dicit: manifestum enim est etc., ostendit quod tria praedicta observata sufficiant ad definiendum, quia definitio neque superfluum neque diminutum habebit. Quod autem non apponatur aliquid plus quam debeat, manifestum est per primum trium praedictorum; quia scilicet accepta sunt solum ea quae praedicantur in eo quod quid et talia necesse erat accipere. Similiter etiam manifestum est quod nihil deficit. Aut enim deficeret genus, aut differentia. Sed quod genus non deficiat, patet ex secundo trium praedictorum. Acceptum est enim primum id sine quo non sunt alia, et quod potest esse sine aliis, et hoc est genus. Et cum genere postea acceptae sunt differentiae. Sed quod differentiae omnes sint acceptae, patet per tertium praedictorum trium; quia non amplius potest accipi posterior differentia post illam cuius diximus non esse aliam differentiam; quia iam sequeretur quod ultimum acceptum adhuc differret differentia essentiali, cum tamen dictum sit, quod non differat.	Then (97b1) he shows that the observance of the three aforesaid rules is sufficient for defining, because the definition will have neither more nor less than it should. That no more has been assigned than it should have is obvious from the first rule, namely, because the only things accepted are items predicated in quod quid; and it was necessary to accept such things. Likewise it will be clear that nothing has been omitted. For either the genus or the difference might be missing. But that the genus is not missing is clear from the second rule; for the first thing taken was the item without which the others do not exist, and which can exist without the others: and this is the genus. And with the genus the differences were then taken. But that all the differences have been taken is obvious from the third rule, since there can be no further subsequent difference taken after the one concerning which we have said that it has no difference; otherwise it would follow that what had been admitted to be the last would still differ with an essential difference, whereas it had been said that it does not have a difference.
Similiter etiam ex praemissis patet quod non intermittatur aliqua differentia in medio, per hoc scilicet quod semper accipiuntur primae differentiae. Unde relinquitur quod sufficiat tria praedicta ad definiendum observari.	Similarly, it is obvious from the foregoing that no difference has been left out in the meantime, namely, because first differences are always taken. Hence it remains that for defining it is sufficient that the three aforesaid rules be observed.

Lecture 16 How to search for the definition of a thing by examining things similar to it and dissimilar

Latin	English
	Lecture 16 (97b7-40) HOW TO SEARCH FOR THE DEFINITION OF A THING BY EXAMINING THINGS SIMILAR TO IT AND DISSIMILAR
lib. 2 l. 16 n. 1 Postquam philosophus docuit investigare quod quid est secundum modum maxime congruum, qui est per divisionem generis, hic docet investigare quod quid est alio modo. Et circa hoc tria facit: primo, docet praedictum modum investigandi; secundo, manifestat per exemplum; ibi: ut puta dico etc.; tertio, probat hunc modum esse convenientem; ibi: semper autem est omnis definitio et cetera.	After teaching how to investigate the quod quid according to the most suitable method which is by division of the genus, the Philosopher now teaches another method. Concerning this he does three things. First, he describes the method. Secondly, he gives examples (97b15). Thirdly, he proves that this method is satisfactory (97b26).
lib. 2 l. 16 n. 2 Dicit ergo primo quod si aliquis inquirit definitionem alicuius rei, oportet quod attendat ad ea quae sunt similia illi, et etiam ad ea quae sunt differentia ab illa re. Quod quidem qualiter fieri debeat, ostendit subdens quod primo oportet circa similia considerare quid idem in omnibus inveniatur; puta quid idem inveniatur in omnibus hominibus, qui omnes conveniunt in hoc quod est esse rationale. Postea considerandum est iterum in aliis, quae conveniunt cum primis in eodem genere, et sunt sibi invicem idem specie, sunt autem altera specie ab illis, quae primo accipiebantur, sicut equi ab hominibus: oportet etiam accipere quid sit idem in his, scilicet equis, puta hinnibile.	He says therefore first (97b7) that if someone is searching for the definition of some thing, he should examine things which are similar to it as well as things which are different from it. He shows how this should be done when he says that in those things which are similar, one should consider some item that is the same in all; for example, what is found to be the same in all men is that they all coincide in being rational. After that, one should investigate the things which agree with the first things in genus and are specifically the same among themselves, although specifically different from the things first taken, as horses from men. It is also necessary to investigate what is the same in these things, namely, these horses; say neighing.
Cum ergo accipiatur quid sit idem in omnibus his, scilicet hominibus, quia rationale; et quid sit idem similiter in omnibus aliis, scilicet equis, quia hinnibile; iterum considerandum est si aliquid est idem in istis duobus acceptis, scilicet in rationali et hinnibili. Et ita est considerandum quousque perveniatur ad aliquam unam rationem communem. Haec enim erit definitio rei. Si vero talis consideratio non inducat in unam rationem communem, sed inducat in duas rationes diversas, aut etiam in plures; manifestum erit quod illud cuius definitio quaeritur, non erit unum secundum essentiam, sed plura: et ita non poterit habere unam definitionem.	Then having taken what is the same in all of the former, i.e., men, namely, rational, and what is the same in the others, i.e., horses, namely, neighing, the next step will be to consider whether anything is the same in those two, namely, in rational and neighing. And this method of investigating must be continued until one common formality is found. For this will be the definition of the thing. However, if such an investigation does not uncover one common formality, but leads to two or even several diverse formalities, it will be obvious that the thing whose definition is being sought will not be one thing according to essence but several. Consequently, it will not have one definition.
lib. 2 l. 16 n. 3 Deinde cum dicit: ut puta, si quid est magnanimitas etc., manifestat quod dixerat per exemplum; et dicit quod si quaeramus quid est magnanimitas, debemus attendere ad quosdam magnanimos, ut sciamus quid unum habent in seipsis, in quantum magnanimi sunt. Sicut Alcibiades dictus est magnanimus, et etiam Achilles, et etiam Aiax; qui omnes habent unum quid commune, quod est non sustinere iniurias. Cuius signum est, quod Alcibiades non sustinens iniurias dimicavit, Achilles vero in insaniam versus est propter iram, Aiax autem interfecit seipsum. Iterum debemus considerare in aliis qui dicuntur magnanimi, sicut in Lysandro aut Socrate. Habent enim hoc commune, quod non mutabantur propter prosperitatem fortunae et per infortunia, sed indifferenter se habebant in utrisque.	Then (97b15) he elucidates what he had said with an example, saying that if we would investigate what magnanimity is, we should first of all consider certain magnanimous persons, in order to learn what is the one item they have insofar as they are magnanimous. Thus, Alcibiades was said to be magnanimous, and so were Achilles and Ajax; all of whom have one item in common—not to tolerate insults. The sign of this is that Alcibiades fought rather than accept insults; Achilles went mad from anger; Ajax committed suicide. Then we should consider this in others who are said to be magnanimous, say in Lysander and Socrates. For they have this in common that they were unmoved by good fortune or bad, but were indifferent to both.
Accipiamus ergo haec duo, scilicet impassibilitatem a fortuitis casibus et non tolerare iniurias, et consideremus si est aliquid commune eis. In hoc enim consistit ratio magnanimitatis. Sicut si dicamus quod utrumque contingit propter hoc, quod aliquis existimat se dignum magnis. Ex hoc enim contingit quod homo non patitur iniurias; et ex hoc etiam contingit quod contemnit mutationem exteriorum bonorum, tanquam minimorum. Si autem nihil commune inveniretur illis duobus acceptis, non esset una species magnanimitatis, sed duae. Unde non posset dari una communis definitio.	Therefore, let us take these two items, namely, equanimity in the face of the vicissitudes of life and intolerance of insults, and see if there is anything common to them. For in this consists the notion of magnanimity. For example, we might say that these two things are due to the fact that a person considers himself worthy of great things. For it is from this attitude that a man does not tolerate insults and it is also from this attitude that he scorns fluctuations affecting external goods as being trifles. But if nothing common is to be found in the two items taken, the species of magnanimity would not be one but two. Hence one common definition could not be given.
lib. 2 l. 16 n. 4 Deinde cum dicit: semper autem est omnis etc., ostendit praemissum modum inveniendi quod quid est esse convenientem. Et circa hoc duo facit: primo, ostendit hunc modum esse convenientem; secundo, ostendit quid oportet in hoc modo vitare; ibi: si autem neque disputare et cetera. Circa primum duo facit: primo, ostendit praedictum modum esse convenientem quantum ad terminum, prout scilicet pervenitur ad aliquid commune; secundo, quantum ad processum, prout scilicet proceditur in praedicto modo a particularibus; ibi: faciliusque est singulare et cetera.	Then (97b26) he shows that the above method is well adapted to finding the quod quid. Concerning this he does two things. First, he shows that the method is suitable. Secondly, he shows what should be avoided in this method (97b38). Concerning the first he does two things. First, he shows that the above method is suitable as to its result, namely, as to arriving at something common. Secondly, as to its procedure, namely, inasmuch as it starts with particular cases (97b28).
lib. 2 l. 16 n. 5 Dicit ergo primo quod convenienter dictum est quod oportet inquirentem quod quid est pervenire ad aliquod commune, quia omnis definitio datur de aliquo secundum quod consideratur in universali, non autem secundum quod consideratur in hoc singulari vel in illo. Non enim medicus definit quid sit sanum in hoc oculo huius hominis; sed vel in universali simpliciter quantum ad omnes, vel distinguit sanum secundum diversas species, puta cum dicit hoc esse sanum cholericis, illud autem phlegmaticis.	He says therefore first (97b26) that it was said advisedly that one who is investigating the quod quid must reach something common, because every definition of something is given insofar as that thing is considered in its universality, and not as it is considered in this or that individual. For a physician does not define health as it exists in this eye of this man, but either as it is universally and absolutely in regard to all men, or he distinguishes health according to various species; for example, when he says this to be health for the cholerics, or for the bilious.
lib. 2 l. 16 n. 6 Deinde cum dicit: facilius autem est singulare etc., ostendit praedictum modum esse convenientem quantum ad processum, quo scilicet proceditur a minus communibus ad magis commune. Et hoc dupliciter: primo, ratione facilitatis: procedit enim disciplina a facilioribus. Facilius autem est definire singulare, idest aliquod minus commune, quam universale, quod est magis commune; in quantum scilicet in universalibus, quia sunt minus determinata, magis latent aequivocationes quam in illis quae sunt indifferentia, idest quae non dividuntur per differentias specificas. Et ideo oportet a singularibus definiendo ascendere ad universalia.	Then (97b28) he shows that this method is satisfactory as to procedure, inasmuch as it proceeds from the less common to the more common. And this in two ways: first, by reason of facility. For a discipline begins from the easier things. But it is easier to define something singular, i.e., something less common, than something universal, which is more common; inasmuch as equivocations are less likely to be detected in universals, because they are less determinate, than in things which are undifferentiated, i.e., in things which are not divided by specific differences. Accordingly, one must define by ascending from singulars to universals.
lib. 2 l. 16 n. 7 Secundo, ibi: sicut autem in demonstrationibus etc., ostendit idem ex ratione evidentiae. Sicut enim in demonstrationibus oportet syllogizari praesupponendo aliquid, quod est evidens et manifestum, sic etiam et in terminis, idest in definitionibus. Non enim potest aliquis devenire in cognitionem alicuius ignoti nisi per aliquod notum sive aliquis intendat cognoscere quia est, quod fit per demonstrationem, sive quid est, quod fit per definitionem.	Secondly (97b31), he shows the same thing by reason of evidence. For just as in demonstrations one should syllogize by presupposing something which is evident and obvious, so too in terms, i.e., in definitions. For no one can pass to a knowledge of something which is unknown except by means of something known, whether he intends to know quia est, which is made known through demonstration, or quid est, which is done by definition.
Hoc autem contingit, ut scilicet praeexistat aliquid evidens, si sit, idest contingat, separatim, idest distinctim, definiri per ea quae singulariter dicuntur, idest quae proprie conveniunt et distincte huic vel illi; sicut si aliquis velit notificare quid est simile, non considerabit ad omne id quod potest simile dici, sed de quibusdam similibus; puta quomodo dicatur simile in coloribus, et quomodo dicatur simile in figuris. Dicitur enim simile in coloribus ex unitate coloris; dicitur autem simile in figuris ex eo quod anguli sunt aequales, et latera proportionalia. Similiter etiam in aliis, si velit definire acutum non respiciet ad omne quod dici potest acutum, sed respiciet ad acutum secundum quod dicitur in voce. Et per hunc modum patet quod aliquis definire intendens refugit statim ne contingat aliqua aequivocatio.	But this happens, i.e., something evident preexists, if it is defined or happens to be defined separately, i.e., distinctly, by means of items that are predicated singularly, i.e., which belong to this or that thing properly and distinctively. Thus, if someone desires to know what similar is, he will not examine every single thing which can be called similar, but only some similar things; for example, how things are similar in color, and how something is accounted similar in figure. For it is from the unity of color that things are said to be similar in color; but in the realm of figure, two things are similar because corresponding angles are equal and the sides proportional. Likewise in other things: if someone desires to define sharp, he will not examine everything which can be called sharp, but he will consider sharp as applied to a sound.
Et per hoc patet esse convenientem modum definiendi, quo ex inferioribus proceditur ad commune; in quantum scilicet in specialibus specialia definire facilius est, et magis in talibus potest esse nota univocatio.	Hence it is clear that one who follows this method when he defines is automatically avoiding the possibility of equivocation. Consequently, it is clear that this is a practical method of defining, i.e., the method of passing from the less common to the more common, inasmuch as it is easier in special things to define what is special, and univocation can be more easily recognized in such things.
lib. 2 l. 16 n. 8 Deinde cum dicit: si autem non oportet etc., excludit quemdam modum procedendi in definitionibus. Et dicit quod sicut non oportet disputare per metaphoras, ita etiam non oportet definire per metaphoras; utpote si dicamus quod homo est arbor inversa: nec oportet in definitionibus assumere quaecunque metaphorice dicuntur. Cum enim definitiones sint praecipua et efficacissima media in disputationibus, si definitiones darentur per metaphoras, sequeretur quod oporteret ex metaphoris disputare. Hoc autem fieri non debet, quia metaphora accipitur secundum aliquid simile, non autem oportet ut id quod est simile secundum unum, sit simile quantum ad omnia.	Then (97b38) he excludes a certain method of procedure in definitions, saying that just as one may not dispute by metaphors, so he may not define by metaphors; for example, by stating that man is an inverted tree. Furthermore, in definitions one may not use anything stated metaphorically. For since definitions are the most important and most efficacious middles in disputations, it would follow, if definitions were stated in metaphorical terms, that one would have to dispute by metaphors. But this is not valid, because a metaphor is interpreted according to something which is similar; whereas it does not follow, if something is similar in one respect, that it is similar in all respects.

Lecture 17 How to investigate the why in special problems. How certain problems agree as to propter quid

Latin	English
	Lecture 17 (98a1-34) HOW TO INVESTIGATE THE WHY IN SPECIAL PROBLEMS. HOW CERTAIN PROBLEMS AGREE AS TO PROPTER QUID, EITHER BECAUSE THEIR MIDDLES HAVE A KIND OF UNITY OR ARE SUBORDINATED
lib. 2 l. 17 n. 1 Postquam ostendit philosophus quomodo oportet investigare quod quid est, hic ostendit quomodo oportet investigare propter quid. Et circa hoc duo facit: primo, ostendit quomodo oporteat investigari propter quid; secundo, movet quasdam quaestiones circa ipsum propter quid; ibi: de causa autem et cuius est causa et cetera. Circa primum duo facit: primo, ostendit quomodo alicuius quaestionis propositae possit investigari propter quid; secundo, ostendit quomodo diversae quaestiones communicant in propter quid; ibi: eadem autem problemata et cetera. Circa primum duo facit: primo, docet accipere propter quid, accipiendo commune univocum; secundo, accipiendo commune analogum; ibi: amplius autem alius modus et cetera.	After showing how one should go about investigating the quod quid, the Philosopher now shows how one should investigate propter quid. Concerning this he does two things. First, he shows how propter quid should be investigated. Secondly, how diverse questions make use of a common propter quid (98a23). Concerning the first he does two things. First, he shows that one takes the propter quid by taking some common univocal item. Secondly, by taking some common analogous item (9840).
Circa primum duo facit: primo, docet investigare propter quid, accipiendo commune univocum, quod est genus nominatum; secundo, accipiendo quodcunque aliud commune; ibi: nunc quidem igitur et cetera.	Concerning the first he does two things. First, he teaches how to take the propter quid by taking a common univocal item which is a definitively named genus. Secondly, by taking anything else that is common (98a13).
lib. 2 l. 17 n. 2 Dicit ergo primo quod ad hoc quod habeamus propter quid circa singula problemata quae ponuntur, oportet considerare divisiones et subdivisiones, et sic ad singula procedere disputando, supposito communi genere. Ut si aliquis velit considerare propter quid aliquid conveniat aliquibus animalibus, oportet accipere qualia sunt quae conveniunt omni animali. Quibus acceptis, oportet iterato accipere secundum divisionem qualia sunt quae consequuntur primo ad aliquod commune, quod sub animali continetur, puta qualia consequuntur ad omnem avem: et sic semper debemus procedere accipiendo illud quod est primum, in quod scilicet fit immediate divisio; quod etiam supra observabatur in divisionibus quibus proceditur ad investigandum quod quid est.	He says therefore first (98a1) that in order to get the propter quid in regard to individual problems that are proposed, it is required to consider divisions and subdivisions, and so to proceed to the individual cases by disputing, having first supposed a common genus. For example, if someone wished to consider why something belongs to certain types of animals, he would have to discover what items belong to every animal. Once these have been discovered, he would once more consult the divisions to determine what things follow first upon that common item which is contained under animal; for example, what things follow upon every bird. Then one would continue in this manner, always taking the first item into which a given division is immediately divided. This is the very thing that was observed above in the divisions by which one proceeds to investigate quod quid.
Sic autem procedendo manifestum est quod semper poterimus dicere propter quid aliqua insunt his quae continentur sub aliquo communi; ut si velimus scire propter quid aliqua insunt homini et equo, puta somnus et vigilia. Sit ergo animal in quo a, quod est medium; b autem, idest maior extremitas, accipiatur pro his quae inhaerent omni animali, sicut somnus et vigilia; quaedam autem animalium species, puta homo, equus, bos, accipiantur ut minor extremitas, scilicet cde. Sic igitur manifestum est propter quid b, idest somnus vel vigilia sit in d, puta in homine, quia propter a, idest propter hoc quod homo est animal. Et similiter est faciendum in aliis, et in omnibus est eadem ratio observanda. Huiusmodi autem documenti ratio est, quia subiectum est causa propriae passionis. Et ideo si volumus investigare causam alicuius passionis, propter quam insit quibusdam rebus inferioribus, oportet accipere commune quod est proprium subiectum, per cuius definitionem accipitur causa illius passionis.	By thus proceeding it is obvious that we shall always be able to say propter quid certain things are present in those things which are contained under something common. Thus, if we would like to know why certain things such as being asleep and being awake are found in man and horse, we would let animal be that in which A, the middle, is found, and let B, i.e., the major extreme, stand for items that inhere in every animal, say, being asleep and awake. Then we let certain species of animals, such as man, horse, cow, be taken as minor extremes, namely, C, D, E. In this way it is manifest that the reason why B, i.e., being asleep or awake, is found in D, i.e., in man, is that it is due to A, i.e., because man is an animal. Then the same should be done in regard to the others, and the same notion must be observed in all. The reason for this procedure is that the subject is the cause of a proper attribute. Therefore, if we wish to investigate the cause why some attribute is found in certain inferiors, it is necessary to take as common the proper subject through whose definition the cause of that attribute is taken.
lib. 2 l. 17 n. 3 Deinde cum dicit: nunc quidem igitur etc., ostendit quomodo oportet investigare propter quid est, reducendo in aliquod commune, quod non sit genus nominatum; et dicit quod ea quae supra dicta sunt, dicuntur secundum illa communia, quibus nomina sunt assignata; sed oportet non solum in talibus considerare, sed et si quid aliud appareat commune quod insit aliquibus, etiamsi non sit genus, vel si non sit nominatum. Deinde oportet considerare ad quae hoc commune consequatur, et quae sunt illa quae consequuntur ad hoc commune innominatum acceptum. Sicut habere cornua est quoddam commune, cui non est nomen impositum, et quod non est genus. Ad hoc autem commune sequuntur duo: quorum unum est, quod omne animal habens cornua habet multos ventres propter necessitatem ruminationis; quorum unus vocatur echinus, in interioribus existens, asper et capedines habens, ut dicitur in libro de historiis animalium. Aliud autem quod consequitur ad animalia habentia cornua, est quod non habeant dentes in utraque mandibula, sed solum in inferiori, quia materia dentium convertitur in cornua. Item considerandum est ad quae animalia consequatur habere cornua, puta bovem et cervum. Sic enim manifestum erit propter quid haec animalia habent illas proprietates, quia scilicet habent cornua.	Then (98a13) he shows how to investigate the propter quid by arriving at something common which is a genus without a definite name. And he says that what has been stated above applies to those common items to which names have been assigned. However, it is not enough to consider only such items but anything else which seems to be commonly present in them, even if it is not a genus or does not have a name. After that, one must discover what this common factor follows upon, as well as what follows upon this common unnamed factor. For example, to have horns is something common, but it neither has a name nor is it a genus. Furthermore, two things follow upon this common factor: one of these is that every horned animal, because it must chew its cud, has several stomachs; one of which, existing farther in and called echinus, is hard and prickly, as it is stated in The History of Animals II. Another item which follows upon horned animals is that they do not have teeth in both jaws, but only in the lower one, because the dental matter is converted into horns. Again one must consider which animals are apt to have horns, namely, cows and deers. For in that way it will be clear why these animals have those properties, namely, because they have horns.
lib. 2 l. 17 n. 4 Deinde cum dicit: amplius autem alius modus etc., ostendit investigare propter quid reducendo ad aliquod commune analogum; et dicit quod alius modus investigandi propter quid est eligere commune secundum analogiam, idest proportionem. Contingit enim unum accipere analogum, quod non est idem secundum speciem vel genus; sicut os sepiarum, quod vocatur sepion, et spina piscium, et ossa animalium terrestrium. Omnia enim ista conveniunt secundum proportionem, quia eodem modo se habent spinae ad pisces sicut ossa ad terrestria animalia. Ad hoc autem commune analogum quaedam consequuntur propter unitatem proportionis, sicut si communicarent in una natura generis vel speciei, sicut esse coopertum carnibus.	Then (98a20) he shows how to investigate propter quid by arriving at some common analogous item. And he says that another method of investigating propter quid is to select something common according to analogy, i.e., proportion. For it is possible to take something analogous which is not the same according to species or genus: for example, the bone (called sepion) of squid, the spine of fish and the backbone of land animals. For all these agree by proportion, because spine and backbone are related to fish and land animals in the same way. Now because of this unity of proportion certain things follow upon this common analogous item, just as if they shared in one generic or specific nature; for example, to be covered with flesh.
lib. 2 l. 17 n. 5 Deinde cum dicit: eadem autem problemata sunt etc., ostendit quomodo multa problemata conveniunt in eo quod est propter quid: et primo, quantum ad unitatem medii; secundo, quantum ad ordinem mediorum; ibi: alia autem et cetera. Dicit ergo primo quod quaedam problemata sunt eadem, in quantum scilicet conveniunt in eo quod est propter quid. Uno quidem modo propter hoc quod habent idem medium; sicut per hoc medium quod est antiperistasis, idest contra-resistentia vel repercussio, multa demonstrantur. Sunt autem quaedam media eadem non simpliciter, sed genere, quae quibusdam differentiis diversificantur, quae sumuntur vel ex diversitate subiectorum, vel ex diversitate modi fiendi. Sicut si quaeratur propter quid fit echo, aut propter quid apparet, scilicet aliquid in speculo, vel propter quid generatur iris. Omnia enim ista sunt idem problema quantum ad medium propter quid, quod est idem genere: omnia enim causantur ex repercussione. Sed repercussiones differunt specie. Nam echo fit per repercussionem aeris moti a corpore sonante ad aliquod corpus concavum; apparitio autem rei in speculo fit propter hoc quod immutatio medii repercutitur ad speculum; iris autem fit propter hoc quod radii solares repercutiuntur ad vapores humidos.	Then (98a23) he shows how many problems concur as to propter quid. First, as to having one middle. Secondly, as to the order of the middles (98a29). He says therefore first (98a23) that some problems are the same, namely, inasmuch as they agree as to propter quid. In one way, because they have the same middle: thus many things are demonstrated by the middle which is antiperistasis, i.e., counter-resistance or reverberation. On the other hand, some middles are the same not absolutely but in genus, and these are diversified by certain differences which are based either on the diversity of subjects or on the diversity of their ways of coming to be. For example, if it is asked why an echo comes to be, or why something appears, namely, in a mirror, or why a rainbow is formed. For they are the same problem as to the middle propter quid, which is generically the same, since all are caused by a reverberation. However, the reverberations differ specifically. For an echo comes to be through the reverberation of air set in motion by a sounding body toward a concave body; an image in a mirror comes to be by the fact that the modification of the medium is rebounded at the mirror; but the rainbow is formed by the rays of the sun being reflected back by moist vapors.
lib. 2 l. 17 n. 6 Deinde cum dicit: alia autem ex eo quod medium etc., ostendit quomodo problemata conveniunt in propter quid secundum ordinationem mediorum; et dicit quod quaedam alia problemata sunt, quae differunt ad invicem ex eo quod habent diversa media, quorum unum est sub altero. Et ponit exemplum, utpote si quaeratur propter quid Nilus in fine mensis, scilicet lunaris, magis inundat. Huius enim ratio est, quia finis mensis est magis pluvialis. Quare autem hoc sit, accipitur per aliud medium; propter hoc scilicet quod tunc deficit luna, quae habet dominium super humores, et ideo, deficiente lumine eius, magis commoventur vapores in aere, ex quo causatur pluvia. Et sic patet quod ista duo media sic se habent ad invicem, quod unum eorum est sub alio.	Then (98a29) he shows how problems agree as to propter quid by reason of the subordination of the middles. And he says that there are certain other problems which differ from one another in point of having diverse middles, one of which is under another. And he gives the example that someone wonders why the Nile overflows more near the end of the month, i.e., of the lunar month. For the reason is that there is more rain near the end of the month. And the reason for this is taken from another middle, namely, because the moon which controls moisture is waning then. Consequently, as its light wanes the vapors in the air condense more; and this causes rain. And so it is plain that those two middles are related to one another in the sense that one of them is under the other.

Lecture 18 Co-existence of cause and caused

Latin	English
	Lecture 18 (98a35-b40) CO-EXISTENCE OF CAUSE AND CAUSED
lib. 2 l. 18 n. 1 Postquam philosophus ostendit quomodo oportet investigare propter quid, hic movet duas quaestiones circa ipsum propter quid, quarum prima est de coexistentia causae ad causatum, secunda pertinet ad unitatem causae; ibi: utrum autem contingat et cetera. Circa primum tria facit: primo, proponit quaestionem; secundo, obiicit; ibi: si enim non est etc.; tertio, solvit; ibi: aut contingit unius et cetera.	After showing how one should investigate propter quid, the Philosopher now raises two questions in regard to propter quid. The first of these concerns the co-existence of cause to caused. The second pertains to the unity of cause (99a1) [L. 19]. Concerning the first he does three things. First, he proposes the question. Secondly, he raises an objection (98b2). Thirdly, he solves the question (98b25).
lib. 2 l. 18 n. 2 Dicit ergo primo quod de causa et causato potest aliquis dubitare utrum quando est unum eorum, sit et aliud. Quae quidem quaestio non est intelligenda quantum ad simultatem temporis, sed quantum ad simultatem consecutionis, utpote si posito uno consequatur aliud vel simul tempore, vel prius et post. Et ponit duo exempla. In quorum uno causa tempore praecedit causatum: nam lata folia habere est causa quod fluant folia alicuius arboris; non autem habere lata folia et folia fluere sunt simul tempore. In alio autem exemplo causa et causatum sunt simul tempore, sicut interpositio terrae simul tempore est cum defectu lunae. Est ergo quaestio utrum ad unum istorum consequatur aliud.	He says therefore first (98a35) that in regard to cause and caused, it is possible to wonder when one of them exists, does the other also exist? However, this question should not be interpreted as referring to coexistence in time but of succession, such that if one is posited, does the other follow regardless of whether they are concurrent in time, or before and after. And he gives two examples. In one of them, the cause precedes the caused in time: for the cause why the leaves of a tree fall off is that it has broad leaves; for the possession of broad leaves and their falling are not simultaneous in time. In the other example, the cause and the caused are simultaneous in time; as the interposition of the earth is simultaneous in time with the eclipse of the moon. The question, therefore, is whether upon the one of them the other follows.
lib. 2 l. 18 n. 3 Deinde cum dicit: si enim non aliqua etc., obiicit ad propositam quaestionem, ostendens quod causa et causatum semper simul sunt secundum consequentiam; et ponit ad hoc duas rationes. Quarum prima sumitur ex ratione causae et causati; et dicit quod omne causatum oportet quod habeat aliquam causam. Unde si posito isto causato, non simul ponitur quod ista eius causa sit, sequitur quod sit eius aliqua alia causa; et hoc ideo, quia necesse est quod causatum simul sit cum aliqua causa. Sicut ad hoc quod est terram esse in medio, sequitur quod luna deficiat; et ad hoc quod est arborem habere lata folia, sequitur quod folia eius fluant. Si ergo non est dare aliam causam, sequitur quod simul sit hoc causatum cum hac causa.	Then (98b2) he objects to the question proposed and shows that cause and caused are always together as to succession: and he gives two reasons for this. The first one is based on the notion of cause and caused. And he says that every caused thing must have some cause. Hence, if something is posited as caused and it is not simultaneously posited that such and such is its cause, it follows that something else is its cause. For example, from the fact that the earth is between, it follows that the moon is eclipsed; and from the fact that a tree has broad leaves, it follows that its leaves fall off. Therefore, if there is no other cause, it follows that this caused is simultaneous with its cause.
lib. 2 l. 18 n. 4 Secundam rationem ponit ibi: et si demonstrentur per altera etc., quae quidem sumitur ex hoc quod causa et causatum per invicem demonstrantur. Et circa hoc tria facit: primo, ponit rationem; secundo, removet errorem qui posset consequi; ibi: si autem non contingit etc.; tertio, probat quoddam quod supposuerat; ibi: quod autem non deficere et cetera.	Then (98b4) he gives the second reason which is based on the fact that cause and caused are demonstrated the one by the other. Concerning this he does three things. First, he states the reason. Secondly, he dismisses the error that could follow (98b16). Thirdly, he proves what he had presupposed (98b22).
lib. 2 l. 18 n. 5 Circa primum dicit quod etiam manifestum est quod causa et causatum simul se consequuntur, si hoc verum est, quod per invicem demonstrentur; quia ad medium demonstrationis ex necessitate sequitur conclusio. Quod autem per invicem demonstrentur, probat in praedicto exemplo. Sit enim folium fluere in quo a, quae est maior extremitas; latum folium habere in quo b, quod est medium; vites vero accipiantur in quo c, quod est minor extremitas. Sic igitur in b est a, quia omne quod habet latum folium, folio fluit; in c autem est b, quia omnis vitis habet lata folia; et sic concluditur quod a est in c, idest quod omnis vitis folio fluit. Et in toto hoc processu causa accipitur pro medio, et sic causatum per causam demonstratur.	In regard to the first he says (98b4) that it is also manifest that cause and caused follow upon one another simultaneously, if it is true that either can be demonstrated by the other: because the conclusion of a demonstration follows of necessity from the middle. But the fact that either can be demonstrated by the other is shown by the following example: Let leaf falls off be A, the major extreme; to have a broad leaf be B, the middle; and vines be C, which is the minor. Thus, therefore, A is in B, because whatever has broad leaves, its leaves fall off; but B is in C, because every vine has broad leaves. And so it is concluded that A is in C, because every vine loses its leaves. Now in this whole process the cause is taken as middle; consequently, the caused is demonstrated by the cause.
Contingit autem et e converso demonstrare causam per causatum, scilicet quod vitis habet lata folia per hoc quod fluit folio. Accipiatur enim lata folia habere quasi maior extremitas, quae est d; fluere folio quasi medium, quod est e; vitis vero minor extremitas, quae est z. Sic igitur e est in z, quia omnis vitis fluit folio; d autem est in e, quia scilicet omne quod fluit folio, habet lata folia; et ex hoc concluditur quod omnis vitis sit lati folii, et accipitur pro causa in consequendo folio fluere.	But it is also possible conversely to demonstrate the cause through the caused, namely, that a vine has broad leaves because its leaves fall off. For we may take as D, the major term, the fact of having broad leaves; and as E, the middle, the fact that the leaves fall off; and as Z, vine, which is the minor extreme. Thus, therefore, E is in Z, because from every vine the leaves fall off; but D is in E, namely, that whose leaves fall off has broad leaves. From this it is concluded that every vine has broad leaves, which is taken as the cause accounting for the leaves falling off.
lib. 2 l. 18 n. 6 Deinde cum dicit: si autem non contingit etc., excludit quemdam errorem, qui posset sequi ex praemissis, ut scilicet eadem ratione unum praedictorum demonstretur ex alio. Sed ipse excludens hoc dicit quod si non contingit quod aliqua duo sint sibi invicem causae, scilicet in eodem genere (eo quod causa est prior eo cuius est causa; non autem contingit idem esse prius et posterius eodem modo); cum causa defectus lunae sit terram esse in medio, non est possibile quod defectus lunae sit causa eius quod terra sit in medio. Si igitur demonstratio quae est per causam, est demonstratio propter quid, quae autem non est per causam, est ipsius quia, ut in primo habitum est; sequitur quod ille qui per defectum lunae demonstrat quod terra sit in medio, cognoscit quidem quia, non propter quid.	Then (98b16) he excludes an error which could follow from the foregoing, namely, that according to the same reason one of the foregoing may be demonstrated from the other. But he rejects this, saying that if it does not occur that the two given things are mutually causes one of the other, namely, in the same genus of cause (since the cause is prior to that of which it is the cause, and it does not occur that a same thing is prior and subsequent in the same way), then since the cause of the eclipse of the moon is the fact that the earth is between, it is not possible that the eclipse of the moon is the cause of the earth’s being between. Therefore, if a demonstration through cause is a demonstration proper quid, whereas one which is not through the cause is demonstration of the quia, as was established in Book I, it follows that one who demonstrates through the eclipse of the moon that the earth is between, knows quia not propter quid.
lib. 2 l. 18 n. 7 Deinde cum dicit: quod autem non deficere etc., probat quod supposuerat, scilicet quod interpositio terrae sit causa defectus, et non e converso; et dicit manifestum esse quod lunam deficere non est causa eius quod est terram esse in medio, sed e converso; quia in ratione eclipsis ponitur quod terra sit in medio, ut supra dictum est. Cum igitur quid et propter quid sint idem, manifestum est quod defectus lunae cognoscitur per interpositionem terrae, sicut per medium propter quid, et non e converso.	Then (98b22) he proves what he had supposed, namely, that the interposition of the earth is the cause of the eclipse and not the converse. And he says that it is obvious that the eclipsing of the moon is not the cause of the earth’s being between, but it is rather the converse; because in explaining an eclipse it is stated that the earth is between, as has been stated. Therefore, since quid and propter quid are the same, it is clear that the eclipse of the moon is known through the fact that the earth is between, as through a middle which is propter quid; and not conversely.
lib. 2 l. 18 n. 8 Deinde cum dicit: aut contingit unius plures causas etc., solvit praemissam quaestionem ostendens in quibus verum sit quod causa et causatum semper se consequantur, et in quibus non. Et circa hoc duo facit: primo, ostendit in quibus non sit verum; secundo, in quibus sit verum; ibi: aut si semper et cetera. Dicit ergo primo quod contingit aliquid unum commune habere plures causas secundum quod convenit diversis, sicut esse vituperabile convenit audaci propter excessum, timido autem propter defectum. Accipiatur ergo quod aliquod unum praedicetur de pluribus primo et immediate, et praedicetur a de b primo, et similiter de c, sicut esse vituperabile de superabundantia et defectu; et ista duo, scilicet c et b, praedicentur de d et e, sicut superabundantia convenit audaci, defectus autem timido. Praedicabitur itaque a de d et e, quia tam audax quam timidus est vituperabilis. Causa autem quod a sit in d est ipsum b: est enim audax vituperabilis propter superabundantiam. Quod autem a insit ipsi e, causa est ipsum c: timidus enim vituperabilis est propter defectum. Patet ergo quod cum causa sit, necesse est rem esse; quia sive a sit superabundantia, sive defectus, necesse est aliquid esse vituperabile. Sed existente re, necesse est quidem quod aliqua causarum sit, non tamen necesse est quamlibet causam esse. Sicut posito quod aliquid sit vituperabile, non est necesse quod sit in superabundantia, sed necesse est quod sit vel in superabundantia vel in defectu.	Then (98b25) he solves the proposed question, showing the cases in which it is true that cause and caused always follow upon one another, and the cases in which it is not true. Concerning this he does two things. First, he shows the cases in which it is not true. Secondly, those in which it is true (98b32). He says therefore first (98b25) that one common thing happens to have several causes, insofar as it is found in diverse things; as to be worthy of blame belongs to a rash person because of excess, but to a timid person because of a deficiency. Therefore, let us assume that some thing is predicated of several things chiefly and immediately, i.e., that A is predicated in a first way of B and also of C; as to be blameworthy is predicated of excessiveness and deficiency. Let us further assume that these two, namely, C and B, are predicated of D and E; as excessiveness of rash, and deficiency of timid. Therefore, A will be predicated of D and of E, because both the rash and the timid are blameworthy. But the cause of A’s being in D is B; for a rash person is blameworthy because of excess. But the cause of A’s being in E is C; for a timid person is blameworthy because of defect. It is clear, therefore, that since the cause exists, the thing must exist: because whether A is excess or defect, it is necessary that something be blameworthy. On the other hand, if the thing exists, it is necessary that one of the causes exist, although it is not necessary that both causes exist. For example, supposing that something is blameworthy, it is not necessary that it be due to excess, but it is necessary that it be due either to excess or to defect.
lib. 2 l. 18 n. 9 Deinde cum dicit: aut si semper est universale etc., ostendit in quibus necesse sit simul se consequi causam et causatum; et dicit quod si aliquid quaeratur in universali, et accipiatur tam causa quam id cuius causa quaeritur, in universali; tunc oportet quod ad causam semper sequatur effectus, et ad effectum causa. Sicut hoc quod est fluere folio, non convenit primo pluribus, ut erat in praemisso exemplo, sed determinate uni primo communi, quamvis illius communis sint multae species, quibus universaliter convenit quod fluunt folio; puta si accipiamus vel plantas vel tales plantas, scilicet lata folia habentes. Unde in omnibus istis oportet accipere aequale medium, ita quod convertatur causa et id cuius est causa. Sicut si quaeramus quare arbores fluant folio; si accipiatur causa huius esse propter hoc quod humidum est condensatum et sic facilius est desiccabile, sequetur quod si causatum sit, quod etiam causa sit; puta si fluit arbor, oportet quod sit condensatio humoris. Et e converso, oportet quod posita causa in tali subiecto ponatur effectus; ut puta si condensatio humoris est, non in quacunque re sed in arbore, sequitur quod folio fluat.	Then (98b32) he shows in which cases it is necessary that cause and caused follow one another simultaneously. And he says that if something be asked in a universal way, and if both the cause and that whose cause is sought be taken in a universal way, then it is required that the effect always follow upon the cause, and the cause upon the effect. Thus the fact of losing leaves does not belong in a first way to several things as it did in the above example, but it belongs determinately to one common first thing; although of that common thing there are many species, to which it belongs universally that their leaves fall off: say, if we took either plants or this type of plant, namely, the type that has broad leaves. Hence in all of these it is required to take an equal middle, so that the cause and that of which it is the cause are converted. Thus we might inquire why trees lose their leaves: if the cause of this is taken to be the fact that the moist element has hardened and made easier to dry out, it will follow that if the effect exists, the cause also exists; for example, if the tree has its leaves falling off, it is required that there be a hardening of its moist element. Conversely, it is required that if the cause is posited, then the effect is posited in such a thing: thus if the hardening of the sap exists, it follows not of anything at random but of the tree, that the leaves fall off.

Lecture 19 Whether upon unity of cause follows unity of effect, and vice versa. How cause and effect follow upon one another

Latin	English
	Lecture 19 (99a1-b18) WHETHER UPON UNITY OF CAUSE FOLLOWS UNITY OF EFFECT, AND VICE VERSA HOW CAUSE AND EFFECT FOLLOW UPON ONE ANOTHER
lib. 2 l. 19 n. 1 Postquam philosophus determinavit quaestionem motam, utrum ad existentiam effectus sequatur existentia causae, et e converso; hic inquirit utrum ad unitatem causae sequatur unitas effectus et e converso. Et circa hoc duo facit: primo, ostendit quomodo ad unitatem effectus sequatur unitas causae; secundo, ex hoc manifestat consecutionem causae et effectus; ibi: habet autem sic consequi et cetera. Circa primum tria facit: primo, proponit quaestionem; quae est, utrum contingat quod eiusdem effectus non sit eadem causa in omnibus, sed alia et alia, vel non. Videbatur enim in solutione praemissae quaestionis supponi quod contingat unius effectus in diversis rebus esse diversas causas.	Having settled the question he raised, namely, whether upon the existence of the effect the existence of the cause follows, and conversely; the Philosopher now inquires whether unity of cause follows upon unity of effect, and conversely. Concerning this he does two things. First, he shows how one cause is inferred from one effect. Secondly, from this he shows the sequential connection of cause and effect (99a17). In regard to the first he does three things. First (99a1) he proposes the question, which is this: Does it occur that of the same effect there is not the same cause in all cases but different ones, or does this not occur? For it seemed to be supposed in solving the previous question that in various cases there can be various causes of one effect.
lib. 2 l. 19 n. 2 Secundo, ibi: aut si quidem per se etc., solvit quaestionem distinguendo. Contingit enim aliquid assignari pro causa alicuius effectus tripliciter: uno modo, accipiendo causam per se, et sic demonstrative concludendo effectum; alio modo, accipiendo aliquod signum; tertio modo, accipiendo aliquod accidens. Si ergo accipiatur pro causa id quod per se est medium demonstrationis, non potest esse nisi una causa unius effectus in omnibus. Et hoc probat quia medium per se in demonstrationibus est ratio ultimi, idest definitio maioris extremitatis. Quae tamen si demonstrari indigeat de subiecto, demonstrabitur per definitionem subiecti, ut supra habitum est. Manifestum est autem quod unius una est definitio. Unde oportet quod unius effectus non accipiatur nisi una causa, quae est medium demonstrationis.	Secondly (99a2), he solves the question by distinguishing. For it occurs that something is assigned as the cause of some effect in three ways: in one way, by taking the per se cause and then concluding the effect demonstratively; in another way, by taking a sign; in a third way, by taking an accident. Therefore, if one takes as cause that which is per se the middle of demonstration, there can be but one cause of one effect in all cases. And he proves this on the ground that a per se middle in demonstrations is a formality of the ultimate, i.e., the definition of the major extreme, which, if it needs to be demonstrated of the subject, will be demonstrated by the definition of the subject, as we have established above. Now it is obvious that of one thing there is one definition. Hence it is necessary that of one effect there is no cause but the one which is the middle of demonstration.
Si vero non accipiatur quasi causa inferens, id quod est per se medium demonstrationis, sed accipiatur pro medio aliquod signum vel aliquod accidens, tunc contingit unius effectus accipi quasi plures causas in diversis, sicut patet in exemplo superius posito. Per se enim causa quod aliquid sit vituperabile, est esse praeter rationem rectam. Sed quod aliquid sit superabundans vel deficiens, est signum eius quod est praeter rationem rectam.	However, if one does not take as the inferring cause that which is per se the middle of demonstration, but some sign or accident is used as the middle, then it does happen that of one effect several causes, as it were, are taken in diverse things, as is clear in the example given earlier. For the per se cause why something is blameworthy is that it is not according to reason. But to be excessive or defective is a sign of that which is not according to reason.
lib. 2 l. 19 n. 3 Tertio, ibi: est autem et causam et etc., manifestat positam solutionem, ostendens membra divisionis positae esse possibilia. Et dicit quod contingit et id quod est causa et id cuius est causa considerare secundum accidens; sicut musicus per accidens est causa domus, cuius per se est causa aedificator, qui tamen est causa receptaculi latronum per accidens, si contingat hoc in domo fieri: quinimo etiam ipsa problemata videntur esse per accidens. Si vero non accipiantur per accidens causa et causatum, oportet quod medium quod accipitur pro causa, similiter se habeat cum effectu, cuius demonstratio quaeritur.	Thirdly (99a4), he elucidates his solution by showing that the members of the division he cited are possible. And he says that it is possible to consider both that which is the cause and that of which it is the cause, per accidens: thus a musician is per accidens the cause of a house whose per se cause is a builder, who in turn is per accidens the cause of its being a haven for thieves, if this happens to occur in the house. Indeed, these problems even seem to be per accidens. But if cause and caused are not taken per accidens, it is required that the middle taken as cause be of the same order as the effect whose demonstration is sought.
Utpote si aliqua sint aequivoca, et medium commune quod accipitur, erit aequivocum. Si autem non sint aequivoca, sed conveniant quasi in genere, et medium erit commune secundum genus; sicut vicissim analogum, idest commutatim proportionari, univoce in multis invenitur, puta in numeris et in lineis, in quibus habet quodammodo aliam causam, et quodammodo eamdem. Aliam quidem secundum speciem, in quantum scilicet alii sunt numeri et aliae lineae: sed est genere eadem, in quantum scilicet tam lineae quam numeri conveniunt in hoc quod habent tale augmentum, ex quo in eis commutata proportio demonstratur.	Hence if certain things are equivocal, then the common middle which is taken will also be equivocal; if they are not equivocal but agree as it were in genus, then the middle too will be common according to genus. Thus the fact that proportionals alternate, i.e., are commutatively proportional, is found univocally in many things, say in numbers and in lines, in which they have a cause which is in one sense different and in one sense the same: different, indeed, according to species, inasmuch as a line is one thing and a number another thing; but the same according to genus, inasmuch as lines as well as numbers agree in having such increments from which commutative proportion is demonstrated of them.
Aliud autem exemplum subiungit in aequivocis; et dicit quod eius quod est esse simile, alia causa est in coloribus et in figuris, quia aequivoce dicitur utrobique. In figuris enim nihil est aliud esse simile, quam quod latera habeant analogiam, idest quod sint ad invicem proportionalia, et quod anguli sint aequales. Sed in coloribus esse simile est quod faciant eamdem immutationem in sensu, vel aliquid aliud huiusmodi. Tertio autem dicit de his quae conveniunt secundum analogiam, quod in his etiam oportet esse medium unum secundum analogiam; sicut supra dictum est quod tam iris quam echo est quaedam repercussio.	The other examples he gives concern equivocal things. He says that the cause of being similar is one thing in colors and another in figures, because similarity is predicated equivocally of the two. For in figures, to be similar consists in nothing more than that the sides have anology, i.e., that the sides are proportional and the angles equal. But in colors, similarity consists in the fact that they cause the same alteration in the sense, or something else of this sort. Thirdly, however, he says concerning things which agree according to analogy that in their case it is also required that the middle be one according to analogy, as when it was stated above that both a rainbow and an echo are reverberations.
lib. 2 l. 19 n. 4 Deinde cum dicit: habet autem sic consequi causam etc., ostendit secundum praemissa qualiter sibi invicem causae consequantur. Et circa hoc tria facit: primo, ostendit qualis sit consecutio causae et effectus; secundo, ordinat huiusmodi consequentiam in figura syllogistica; ibi: in figuris autem etc.; tertio, movet quamdam dubitationem ex praemissis; ibi: si autem in atomum et cetera.	Then (99a17) he shows how in the light of the foregoing, causes follow one upon the other. Concerning this he does three things. First, he shows what sort of sequential connection there is between cause and effect. Secondly, he orders this connection in a syllogistic figure (99a30). Thirdly, he raises a doubt from the foregoing (99b7).
Dicit ergo primo quod talis modus consequentiae invenitur inter causam et causatum et subiectum cui inest illud causatum, quod si aliquis accipiat secundum unum aliquid particulare id cuius causa quaeritur, erit in plus quam causa vel subiectum; sicut habere angulos extrinsecos aequales quatuor rectis convenit triangulo eadem ratione, quia tres anguli eius extrinseci simul cum tribus intrinsecis sunt aequales sex rectis. Cum igitur tres intrinseci sint aequales duobus rectis, sequitur quod tres extrinseci sint aequales quatuor rectis. Etiam quadrangulus habet quatuor angulos aequales quatuor rectis, sed alia ratione. Anguli enim eius intrinseci et extrinseci sunt aequales octo rectis; sed anguli intrinseci quadranguli sunt aequales quatuor rectis; ergo anguli extrinseci sunt aequales quatuor rectis. Sic igitur habere angulos exteriores aequales quatuor rectis, est in plus quam triangulus aut quadrangulus: sed si simul accipiantur, aequaliter se habebunt. Quaecunque enim figurae communicant in hoc quod habeant angulos exteriores aequales quatuor rectis, oportet quod similiter communicent in medio, quod est causa aequalitatis ad quatuor angulos rectos. Et hoc probat sicut et prius, per hoc quod medium est definitio maioris extremitatis. Et inde est quod omnes scientiae fiunt per definitionem.	He says therefore first (99a17) that the type of connection found between cause and caused and the subject in which that caused inheres is such that if one were to take in a particular case that of which the cause is sought, it will be in more than the cause or subject. Thus, to have its exterior angles equal to four right angles belongs to every triangle for a single reason, namely, because its three exterior angles added to its three interior angles are equal to six right angles. Therefore, since the three interior angles are equal to two right angles, it follows that the three exterior angles are equal to four right angles. However, a rhombus also has four exterior angles equal to four right angles, but for another reason. For its exterior angles plus its interior angles equal eight right angles, but the four interior angles of a rhombus are equal to four right angles; therefore, the four exterior angles are equal to four right angles. Therefore, to have its exterior angles equal to four right angles extends to more things than either triangle or rhombus does; but if the latter are taken together, they are equal to the former. For all figures, which agree in having their exterior angles equal to four right angles must similarly agree as to their middle, which is the cause of being equal to four right angles. And he proves this, as in the previous case, on the ground that the middle is the definition of the major extreme. And this is why all sciences come to be in virtue of a definition.
Probat autem hoc per exemplum in rebus naturalibus. Hoc enim quod est folio fluere, consequitur ad vitem et excedit ipsam, quia est in pluribus; consequitur etiam ad ficum et excedit eam: non tamen est excessivum omnium quibus convenit, sed est eorum sicut aequalium. Si ergo aliquis velit accipere id quod est primum medium respectu omnium, erit haec definitio eius quod est folio fluere; quae quidem definitio erit primum medium ad alia, eo quod omnia talia sunt. Et iterum huius accipietur aliquod aliud medium, puta quod succus densatur per desiccationem, vel aliquod aliud huiusmodi. Unde si quaeratur quid est folio fluere, dicemus quod nihil aliud est quam condensari succum seminis in contactu, scilicet folii ad ramum.	He proves this also with an example from natural things. For the fact that its leaves fall follows on being a vine, but it extends to more, because it is true of several other things; it also follows upon being a fig tree, and extends to more. But it does not extend to more than the sum total of things in which it is found, but it is equal to their sum. Therefore, if someone desires to discover what is the first middle in relation to all, it will be the definition of the fact that the leaves fall: and this definition will be the first middle in respect to the others, since all the others are such. And again, some other middle will be discovered for this, say that the sap hardens by drying, or something of that sort. Hence, if it be asked what it is to have leaves fall off, we will say that it is nothing more than “the seminal sap hardening at a point of contact,” i.e., where the leaf meets a branch.
lib. 2 l. 19 n. 5 Deinde cum dicit: in figuris autem sic assignabit etc. ordinat modum praedictae consecutionis in figura syllogistica; et dicit quod si quaeratur consecutio causae et causati, sic poterit assignari secundum figuras syllogismorum. Sit enim a in omni b; b autem in unoquoque eorum quae sunt d, sed in plus quam d. Sic igitur b universaliter erit in his quae continentur sub d, secundum quod universaliter dicitur inesse quod non convertitur. Sed et primum universale est, cui unumquodque quidem contentorum sub eo non convertitur; omnia autem simul accepta convertuntur cum primo universali, et excedunt quodlibet eorum quae sub eo continentur. Sic igitur quod a sit in ipsis quae continentur sub d, causa est b. Oportet ergo quod a extendatur in plus quam b. Si autem non, sed se haberet ex aequo, quare magis b esset causa in inferendo quod a sit in d, quam e converso? Potest enim ex utroque convertibilium concludi aliud.	Then (99a30) he arranges the mode of the aforesaid connection in syllogistic form, saying that if the sequence of cause and caused be sought, it can, be assigned in the following way according to the figures of syllogisms. Thus let A be in every B, and B in all things that are D, but in things additional to D. Then B will inhere universally in the things contained under D, inasmuch as that is said to inhere universally which is not converted. But a primary universal is one such that each of the inferiors contained under it is not converted with it, but all of them taken together are converted with the first universal and exceed each of those which are contained under it. Thus, therefore, the cause of the fact that A inheres in the things contained under D is B. Therefore, it is required that A extend to more things than B does. If this were not so but they were equal, then why should B be the cause of inferring that A is in D, any more than A be the cause of inferring that B is in D? For either of two convertible things can be concluded from the other.
Ponatur igitur ulterius quod a praedicetur de omnibus in quibus est e, sed non convertitur. Oportet ergo dicere quod illa omnia quae continentur sub e, sint aliquid unum diversum ab eo quod est b. Si enim non esset aliud e quam b, quomodo esset verum dicere quod a inesset omni b, et non e converso, cum a non sit nisi in e et in b? Et ita sequeretur, si e et b non essent aliud, quod a non esset in plus quam e. Supponatur ergo quod a sit in plus quam d et quam e. Quare ergo non poterit inveniri aliqua causa propter quam insit omnibus quae sunt in d? Et haec causa est b. Sed adhuc quaerendum est utrum et omnia quae continentur sub e, habeant aliquam unam causam; et sit talis causa c. Sic igitur concludit quod contingit eiusdem esse plures causas, sed non in eodem secundum speciem. Sicut eius quod est a, causa est et b et c: sed b est causa quod a insit his quae continentur sub d, c autem est causa quod a insit his quae continentur sub e. Et ponit exemplum in rebus naturalibus. Sit enim hoc quod est esse longae vitae, quasi a; quadrupedia quasi d; sed non habere choleram, scilicet superfluam, sit quasi b, quod est causa in quadrupedibus longae vitae; volatilia autem sint quasi e; siccum autem esse, vel aliquid aliud huiusmodi, quod est in eis causa longae vitae, aut aliquid aliud huiusmodi sit quasi c.	Suppose, furthermore, that A is predicated of all things in which E inheres, but is not convertible. Then it will be necessary to say that all the things contained under E form one thing, which is diverse from B. For if A were not diverse from B, how could it be true to say that A inheres in every B and not vice versa, since A is only in E and in B? And so it would follow, if E and B were not diverse, that A would not be in more than E. Therefore, suppose that A is in more things than D and than E. Then why could not a cause be found explaining why it is in all things which are in D? And this cause is B. But we must still inquire whether all the things contained under E have one cause. Let C be that cause. Thus, therefore, he concludes that a same thing turns out to have several causes, but not in the same subject according to species. Thus the cause of that which is A is both B and C; but B is the cause that A is found in the things contained under D, while C is the cause that A is found in the things contained under E. And he gives an example from natural things. Let the fact of being long-lived be taken as A; quadrupeds as D; to have no bile, i.e., in superfluity (which is the cause of long life in quadrupeds) as B; birds as E; and to be dry, or something of that sort, which is the cause of long life, or something of that sort in birds, as C.
lib. 2 l. 19 n. 6 Deinde cum dicit: si autem in atomum etc., movet quamdam dubitationem ex praemissis. Dictum est enim supra quod non statim a principio venitur in aliquod atomum, idest indivisibile, in quo inveniatur illud cuius causa quaeritur; sed statim inveniuntur multa et indivisa, in quibus illud unum invenitur, et non est unum medium, per quod de omnibus illud unum demonstretur, et causae plures sunt. Est ergo dubitatio, si illorum plurium mediorum oporteat aliquam causam accipere, utrum oporteat eam accipere ex parte universalis primi, puta ex parte ipsius a; vel ex parte singularium, idest eorum quae sunt minus communia, sicut supra accipiebantur e et d, vel quadrupedia et aves.	Then (99b7) he raises a problem occasioned by the foregoing. For it was stated above that one does not straightway from the beginning arrive at something atomic, i.e., at the indivisible, in which is found that whose cause is being sought. But straightway many and indistinct things are found in which that one thing occurs; furthermore, there is not one middle through which this one thing can be demonstrated of all, and the causes are several. The doubt therefore is this: If some cause is to be taken of these several middles, is it to be taken on the side of the primary universal, say on the side of A, or on the side of the singulars, i.e., of those which are less common, as E and D were taken above, i.e., quadrupeds and birds?
Et ad hoc respondet dicens quod oportet semper media accipere quae sunt propinquiora subiecto, in quo quaeritur causa illius communis causati; et sic oportet procedere quousque perveniatur ad id quod est immediatum communi causato. Et huius rationem assignat, quia illud quod est ex parte eius quod continetur sub aliquo communi, est ei causa quod sit sub illo communi; sicut si d est sub b, et si c sit causa d quod b insit ei. Et ex hoc sequitur ulterius quod c sit causa quod a insit d; et quod a insit c, b est causa. Ipsi autem b inest a per seipsum et immediate.	And he answers this by saying that it is always required to take the middles which are nearer the subject, in which the cause of that common caused thing is searched for: and it is necessary to proceed thus until one readies that which is immediate to the common caused thing. And he assigns a reason for this, namely, because that which is on the part of what is contained under something common is the cause of its being under this common thing; just as is the case if D is under B, and if C is the cause of D having B in it. And from this it further follows that C is the cause of A’s being in D, and that B is the cause of A’s being in C. But A is in B in virtue of itself and immediately.
lib. 2 l. 19 n. 7 Ultimo autem epilogat ea quae dicta sunt in tota doctrina analyticorum; et dicit quod manifestum est ex praemissis, tam in libro priorum quam in hoc libro posteriorum, de syllogismo et de demonstratione, quid sit et quomodo fiat utrumque; et similiter manifestum est de scientia demonstrativa, quomodo fiat in nobis. Hoc enim ad idem pertinet, quia demonstratio est syllogismus faciens scire, ut supra habitum est.	Finally (99b15), he summarizes what has been said in the entire teaching of the Analytics, saying that it is clear from all that has been stated—both in the book of the Prior and in this book of the Posterior—concerning the syllogism and concerning demonstration, both what each is and how each is formed. Furthermore, in regard to demonstrative science it is also clear how it comes to exist in us. For this pertains to the same thing, because demonstration is a syllogism causing scientific knowledge, as has been established above.

Lecture 20 How the first principles of demonstration are known by us

Latin	English
	Lecture 20 (99b18-100b17) HOW THE FIRST PRINCIPLES OF DEMONSTRATION ARE KNOWN BY US
lib. 2 l. 20 n. 1 Postquam philosophus ostendit quomodo cognoscatur illud quod est principium demonstrationis sicut medium, scilicet quid et propter quid, hic ostendit quomodo cognoscantur prima principia demonstrationis communia. Et primo, dicit de quo est intentio; secundo, exequitur propositum; ibi: quod quidem igitur et cetera. Dicit ergo primo quod ex his quae sequuntur, manifestum erit de principiis primis indemonstrabilibus, qualiter eorum cognitio fiat in nobis, et quo habitu cognoscantur; hoc tamen ordine observato, ut prius circa hoc dubitationes ponamus.	After showing how that which is the principle of demonstration in the sense of a middle comes to be known, the Philosopher now shows how the first common principles come to be known. First, he states his intention. Secondly, he pursues it (99b20). He says therefore first (99b18), that from what follows it will be clear concerning indemonstrable principles both how we come to know them and by what habit they are known. However, the plan we shall observe calls for us first to propose certain problems touching this matter.
lib. 2 l. 20 n. 2 Deinde cum dicit: quod quidem igitur non contingit scire etc., exequitur propositum. Et circa hoc duo facit: primo, movet dubitationem; secundo, solvit; ibi: necesse itaque est habere et cetera. Circa primum tria facit: primo, praemittit quoddam ex quo ostenditur necessitas huiusmodi inquisitionis; secundo, movet quaestiones; ibi: immediatorum autem etc.; tertio, obiicit ad quaestionem; ibi: si quidem et cetera. Dicit ergo primo quod iam supra dictum est, quod non contingit aliquid scire per demonstrationem, nisi praecognoscantur prima principia immediata. Et ideo ad scientiam quae est de demonstratione, utile est ut sciatur qualiter prima principia cognoscantur.	Then (99b20) he pursues his plan. Concerning this he does two things. First, he raises the problem. Secondly, he settles it (99b32). In regard to the first he does three things. First, he prefaces something from which the need for an inquiry of this kind is indicated. Secondly, he raises the questions (99b23). Thirdly, he objects to a question (99b26). He says therefore first (99b20), that it has already been established above that nothing is scientifically known through demonstration, unless the first immediate principles are known beforehand. Therefore, in order to have scientific knowledge of demonstration, it is useful to know how the first principles are acquired.
lib. 2 l. 20 n. 3 Deinde cum dicit: immediatorum autem cognitio etc., movet dubitationes tres circa praedictam cognitionem principiorum. Quarum prima est, utrum omnium immediatorum principiorum sit eadem cognitio vel non. Secunda dubitatio est, utrum omnium immediatorum principiorum sit scientia vel nullorum, aut quorumdam sit scientia, aliorum vero aliud genus cognitionis. Tertia quaestio est, utrum habitus istorum principiorum fiant in nobis, cum prius non fuerint, vel semper in nobis fuerunt, sed tamen nos latebat.	Then (99b23) he raises three questions touching this knowledge of the principles. The first question is whether the knowledge of all immediate principles is the same or not. The second is whether there is a science of all immediate principles or of none; or is there science of some, and some other type of knowledge of the others. The third question is whether the habitual knowledge of those principles comes to exist in us after previously not existing, or have they always been in us but escaped our notice.
lib. 2 l. 20 n. 4 Deinde cum dicit: si quidem igitur habemus ipsos etc., obiicit ad quaestionem ultimam, ad quam aliae ordinantur. Et primo obiicit ad unam partem; et dicit quod est inconveniens dicere quod habeamus habitus horum principiorum, et lateat nos. Manifestum est enim quod illi qui habent cognitionem principiorum, habent certiorem cognitionem cognitione quae est per demonstrationem. Sed cognitio quae est per demonstrationem, non potest haberi ita quod lateat habentem. Dictum est enim in principio huius libri, quod ille qui habet scientiam, scit quod impossibile est aliter se habere. Ergo multo minus potest esse quod aliquis habeat cognitionem principiorum immediatorum, et lateat ipsum. Quod tamen inconveniens sequeretur, si habitus huiusmodi inessent, et laterent.	Then (99b26) he objects to the last question to which the others are ordered. First, he objects to the second side, saying that it is absurd to claim that we have the habitual knowledge of these principles but they escape our notice. For it is obvious that those who have knowledge of the principles have a knowledge which is more certain than that which is acquired through demonstration. But knowledge through demonstration cannot be had such that it escapes the notice of the one having it. For it was established in the beginning of this book that a person who has scientific knowledge of something knows that it is impossible for it to be otherwise. Therefore, it is far less possible for someone having a knowledge of the first principles to have it escape his notice. Yet this absurdity would follow, if habitual knowledge of this kind were in us but escaped our notice.
lib. 2 l. 20 n. 5 Secundo, ibi: si autem accipimus etc., obiicit ad contrarium. Si enim aliquis dicat quod accipimus de novo habitus principiorum, cum prius eos non habuerimus, relinquitur ulterius dubitatio qualiter possimus huiusmodi principia de novo cognoscere et addiscere, et hoc non ex aliqua praeexistenti cognitione; impossibile est enim aliquid addiscere nisi ex praeexistenti cognitione, sicut etiam supra circa demonstrationem diximus. Immediata autem principia ideo ex praeexistenti cognitione addiscere non possumus, quia praeexistens cognitio est certior, cum sit causa certitudinis his quae per eam innotescunt. Nulla autem cognitio est certior cognitione huiusmodi principiorum. Unde non videtur quod possimus ea cognoscere, cum prius non cognoverimus.	Secondly (99b28), he objects to the other side. For if a person states that we acquire these habits or principles de novo after previously not having them, we are left with the further problem of how we can know and learn such principles de novo without some previous knowledge existing in us: for it is impossible to learn anything save from preexisting knowledge, as we have established above in regard to demonstration. But the reason why we cannot learn the immediate principles from pre-existing knowledge is that pre-existing knowledge is more certain, since it is a cause of certitude of the things which are made known through it. But no knowledge is more certain than the knowledge of these principles. Hence it does not seem that we can begin to know them, when previously we did not know.
lib. 2 l. 20 n. 6 Tertio, ibi: manifestum igitur est etc., concludit ex praemissis duabus rationibus, quod neque possibile est semper habere cognitionem horum principiorum, quae nos lateat; neque etiam possibile est quod in nobis generetur de novo talis cognitio, omnimoda ignorantia praecedente, et non habito aliquo alio habitu.	Thirdly (99b30), he concludes from the above two arguments that it is neither possible always to have had the knowledge of these principles but it escaped our notice, nor possible that such knowledge is generated de novo in us to supplant a state of absolute ignorance in which no other habitual knowledge was possessed.
lib. 2 l. 20 n. 7 Deinde cum dicit: necesse itaque est etc., solvit praemissas quaestiones. Et primo, solvit ultimam; secundo, solvit duas primas; ibi: quoniam autem eorum qui circa intellectum et cetera. Circa primum duo facit: primo, solvit dubitationem; secundo, manifestat solutionem positam; ibi: quod autem dictum est olim et cetera. Circa primum tria facit: primo, proponit quod oportet aliquid cognoscitivum in nobis praeexistere; secundo, ostendit quid sit illud; ibi: videtur autem etc.; tertio, ostendit quomodo ex praeexistenti cognoscitivo principio fiat in nobis principiorum cognitio; ibi: ex sensu quidem et cetera.	Then (99b32) he solves these questions. First, he solves the last one Secondly, he solves the first two (100b5). In regard to the first he does three things. First, he proposes that some principle of knowing must pre-exist in us. Secondly, he shows what it is (99b34). Thirdly, he shows how from a pre-existing principle of knowing we attain the knowledge of principles (100a4).
Dicit ergo primo quod necesse est a principio in nobis esse quamdam potentiam cognoscitivam, quae scilicet praeexistat cognitioni principiorum; non tamen talem quae sit potior quantum ad certitudinem cognitione principiorum. Unde non eodem modo principiorum cognitio fit in nobis ex praeexistenti cognitione, sicut accidit in his quae cognoscuntur per demonstrationem.	He says therefore first (99b32), that there must be in us from the beginning a certain cognitive power that exists previously to the knowledge of principles, but not such that it is stronger as to certitude than the knowledge of principles. Hence the knowledge of principles does not come about in us from pre-existing knowledge in the same way as things which are known through demonstration.
lib. 2 l. 20 n. 8 Deinde cum dicit: videtur autem hoc inesse etc., ostendit quid sit illud principium cognoscitivum praeexistens. Et quantum ad hoc ponit tres gradus in animalibus. Quorum primus est hoc, quod videtur inesse communiter omnibus animalibus, quae omnia habent quamdam connaturalem potentiam ad iudicandum de sensibilibus, quae vocatur sensus, quae non acquiritur de novo, sed ipsam naturam consequitur.	Then (99b34) he shows what that pre-existing cognitive principle is. Apropos of this he posits three grades among animals. The first of these is something which seems to be common to all animals, namely, that they have a certain connatural faculty [i.e., potency, i.e., power] for estimating about sense-perceptible things. This faculty, which is not acquired de novo but follows upon their very nature, is called sense.
lib. 2 l. 20 n. 9 Secundum gradum ponit ibi: cum autem insit sensus etc.; et dicit quod cum sensus sit in omnibus animalibus, in quibusdam eorum remanet aliqua impressio sensibilis, abeunte re sensibili, sicut contingit in omnibus animalibus perfectis. In quibusdam autem hoc non contingit, sicut in quibusdam animalibus imperfectis, sicut patet in his quae non moventur motu progressivo. Et forte contingit quod circa aliqua animalia remanet aliqua impressio quantum ad aliqua sensibilia, quae sunt vehementiora, non autem quantum ad alia, quae sunt debiliora. In quibuscunque igitur animalibus omnino nulla impressio remanet sensibilium, huiusmodi animalia nullam cognitionem habent, nisi dum sentiunt. Et similiter animalia in quibus nata est remanere talis impressio, si circa aliqua sensibilia in eis non remaneat, non possunt habere aliquam cognitionem nisi dum sentiunt. Sed animalia in quibus inest huiusmodi remansio impressionis, contingit adhuc habere quamdam cognitionem in anima praeter sensum; et ista sunt quae habent memoriam.	Then (99b36) he mentions the second grade, saying that although sense is found in all animals, in some of them a sensible impression remains after the sense-object is removed, as happens in all the perfect animals. But in certain others this does not occur, as in certain imperfect animals; say in those which are not capable of progressive local movement. And it might perhaps be that in regard to some animals an impression remains in regard to certain sense-objects which are more vigorous, and not in regard to those which are weaker. Therefore, those animals in which no impression of sensible objects remains at all have no knowledge except when they are sensing. Similarly, in regard to animals in which such an impression is apt to remain, if it does not remain in them in the case of certain sensible objects, they cannot have any knowledge of them except while they are sensing. But animals, in which a trace of such an impression remains, are capable of having some knowledge in the mind beyond sense; and these are the animals which have memory.
lib. 2 l. 20 n. 10 Tertium gradum ponit ibi: multis igitur factis etc.; et dicit quod cum multa sint talia animalia habentia memoriam, inter ea ulterius est quaedam differentia. Nam in quibusdam eorum fit ratiocinatio de his quae remanent in memoria, sicut in hominibus; in quibusdam autem non, sicut in brutis.
lib. 2 l. 20 n. 11 Deinde cum dicit: ex sensu quidem igitur etc., ostendit secundum praedicta quomodo in nobis fiat cognitio primorum principiorum, et concludit ex praemissis quod ex sensu fit memoria in illis animalibus, in quibus remanet impressio sensibilis, sicut supra dictum est. Ex memoria autem multoties facta circa eamdem rem, in diversis tamen singularibus, fit experimentum; quia experimentum nihil aliud esse videtur quam accipere aliquid ex multis in memoria retentis. Sed tamen experimentum indiget aliqua ratiocinatione circa particularia, per quam confertur unum ad aliud, quod est proprium rationis. Puta cum aliquis recordatur quod talis herba multoties sanavit multos a febre, dicitur esse experimentum quod talis sit sanativa febris.	Then (100a1) he shows, in view of the foregoing, how the knowledge of first principles comes about in us; and he concludes from the foregoing that from sensing comes remembrance in those animals in which a sensible impression remains, as has been stated above. But from remembrance many times repeated in regard to the same item but in diverse singulars arises experience, because experience seems to be nothing else than to take something from many things retained in the memory. However, experience requires some reasoning about the particulars, in that one is compared to another: and this is peculiar to reason. Thus, when one recalls that such a herb cured several men of fever, there is said to be experience that such a herb cures fevers.
Ratio autem non sistit in experimento particularium, sed ex multis particularibus in quibus expertus est, accipit unum commune, quod firmatur in anima, et considerat illud absque consideratione alicuius singularium; et hoc commune accipit ut principium artis et scientiae. Puta quamdiu medicus consideravit hanc herbam sanasse Socratem febrientem, et Platonem, et multos alios singulares homines, est experimentum; cum autem sua consideratio ad hoc ascendit quod talis species herbae sanat febrientem simpliciter, hoc accipitur ut quaedam regula artis medicinae.	But reason does not stop at the experience gathered from particulars, but from many particulars in which it has been experienced, it takes one common item which is consolidated in the mind and considers it without considering any of the singulars. This common item reason takes as a principle of art and science. For example, as long as a doctor considered that this herb cured Socrates of fever, and Plato and many other individual men, it is experience; but when his considerations arise to the fact that such a species of herb heals a fever absolutely, this is taken as a rule of the art of medicine.
Hoc est ergo quod dicit, quod sicut ex memoria fit experimentum, ita etiam ex experimento, aut etiam ulterius ex universali quiescente in anima (quod scilicet accipitur ac si in omnibus ita sit, sicut est experimentum in quibusdam. Quod quidem universale dicitur esse quiescens in anima; in quantum scilicet consideratur praeter singularia, in quibus est motus. Quod etiam dicit esse unum praeter multa, non quidem secundum esse, sed secundum considerationem intellectus, qui considerat naturam aliquam, puta hominis, non respiciendo ad Socratem et Platonem. Quod etsi secundum considerationem intellectus sit unum praeter multa, tamen secundum esse est in omnibus singularibus unum et idem, non quidem numero, quasi sit eadem humanitas numero omnium hominum, sed secundum rationem speciei. Sicut enim hoc album est simile illi albo in albedine, non quasi una numero albedine existente in utroque, ita etiam Socrates est similis Platoni in humanitate, non quasi una humanitate numero in utroque existente) ex hoc igitur experimento, et ex tali universali per experimentum accepto, est in anima id quod est principium artis et scientiae.	This, then, is what he means when he says that just as from memory is formed experience, so from experience or even from the universal resting in the mind (which, namely, is taken as if it is so in all cases, just as experience is taken as being so in certain cases.—This universal is said to be resting in the mind, inasmuch as it is considered outside the singulars, which undergo change. Furthermore, he says that it is one outside the many, not according to an autonomous existence but according to the consideration of the intellect which considers a nature, say of man, without referring to Socrates and Plato. But even though it is one outside the many according to the intellect’s consideration, nevertheless in the sphere of existents it exists in all singulars one and the same: not numerically, however, as though the humanity of all men were numerically one, but according to the notion of the species. For just as this white is similar to that white in whiteness, not as though there were one numerical whiteness existing in the two, so too Socrates is similar to Plato in humanity, but not as though there were numerically one humanity existing in the two.—) the principle of art and science is formed in the mind.
Et distinguit inter artem et scientiam, sicut etiam in VI Ethic., ubi dicitur quod ars est recta ratio factibilium. Et ideo hic dicit quod si ex experimento accipiatur aliquod universale circa generationem, idest circa quaecunque factibilia, puta circa sanationem vel agriculturam, hoc pertinet ad artem. Scientia vero, ut ibidem dicitur, est circa necessaria; et ideo si universale consideretur circa ea quae semper eodem modo sunt, pertinet ad scientiam, puta circa numeros vel figuras. Et iste modus qui dictus est, competit in principiis omnium scientiarum et artium. Unde concludit quod neque praeexistunt in nobis habitus principiorum, quasi determinati et completi; neque etiam fiunt de novo ab aliquibus notioribus habitibus praeexistentibus, sicut generatur in nobis habitus scientiae ex praecognitione principiorum; sed habitus principiorum fiunt in nobis a sensu praeexistente.	And he distinguishes between art and science, just as he did in Ethics VI, where it is stated that art is right reason in regard to things to be made. And so he says here that if from experience a universal in regard, to generation is taken, i.e., in regard to anything that can be made, say in regard to healing or husbandry, this pertains to art. Science, however, as it is stated in the same place, is concerned with necessary things; hence if the universal bears on things which are always in the same way, it pertains to science; for example, if it bears on numbers or figures. And this process which has been described is verified in regard to the principle of all sciences and arts. Hence he concludes that there do not pre-exist, any habits of principles in the sense of being determinate and complete, neither do they come to exist anew from other better known pre-existing principles in the way that a scientific habit is generated in us from previously known principles; rather the habits of principles come to exist in us from pre-existing sense.
Et ponit exemplum in pugnis quae fiunt per reversionem exercitus devicti et fugati. Cum enim unus eorum perfecerit statum, idest immobiliter ceperit stare et non fugere, alter stat adiungens se ei, et postea alter, quousque tot congregentur quod faciant principium pugnae. Sic etiam ex sensu et memoria unius particularis, et iterum alterius et alterius, quandoque pervenitur ad id quod est principium artis et scientiae, ut dictum est.	And he gives as an example a battle which starts after the soldiers have been beaten and put to flight. For when one of the soldiers shall have, taken a stand, i.e., begun to take a battle position and not flee, another takes his stand next to him, and then another, until enough are gathered to form the beginning of a battle. So, too, from the sense and memory of one particular and then of another and another, something is finally reached which is the principle of art and science, as has been stated.
lib. 2 l. 20 n. 12 Posset autem aliquis credere quod solus sensus, vel memoria singularium sufficiat ad causandum intelligibilem cognitionem principiorum, sicut posuerunt quidam antiqui, non discernentes inter sensum et intellectum; et ideo ad hoc excludendum philosophus subdit quod simul cum sensu oportet praesupponere talem naturam animae, quae possit pati hoc, idest quae sit susceptiva cognitionis universalis, quod quidem fit per intellectum possibilem; et iterum quae possit agere hoc secundum intellectum agentem, qui facit intelligibilia in actu per abstractionem universalium a singularibus.	But someone could believe that sense alone or the mere remembrance of singulars is sufficient to cause intellectual knowledge of principles, as some of the ancients supposed, who did not discriminate between sense and intellect. Therefore, to exclude this the Philosopher adds that along with sense it is necessary to presuppose such a nature of mind as cannot only suffer this (i.e., be susceptible of universal knowledge, which indeed comes to pass in virtue of the possible intellect) but can also cause this in virtue of the agent intellect which makes things intelligible in act by abstraction of universals from singulars.
lib. 2 l. 20 n. 13 Deinde cum dicit: quod autem dictum est etc., manifestat quod dictum est in praecedenti solutione, quantum ad hoc quod ex experimento singularium accipitur universale; et dicit quod illud quod supra dictum est, et non plane, quomodo scilicet ex experimento singularium fiat universale in anima, iterum oportet dicere, ut planius manifestetur. Si enim accipiantur multa singularia, quae sunt indifferentia quantum ad aliquid unum in eis existens, illud unum secundum quod non differunt, in anima acceptum, est primum universale, quidquid sit illud, sive scilicet pertineat ad essentiam singularium, sive non. Quia enim invenimus Socratem et Platonem et multos alios esse indifferentes quantum ad albedinem, accipimus hoc unum, scilicet album, quasi universale quod est accidens. Et similiter quia invenimus Socratem et Platonem et alios esse indifferentes quantum ad rationalitatem, hoc unum in quo non differunt, scilicet rationale, accipimus quasi universale quod est differentia.	Then (100a4) he elucidates something asserted in the preceding solution, namely, that the universal is taken from experience bearing on singulars. And he says that what was stated above, albeit not clearly—namely, how from the experience of singulars the universal is formed in the mind—must now be discussed again and explained more clearly. For if many singulars are taken which are without differences as to some one item existing in them, that one item according to which they are not different, once it is received in the mind, is the first universal, no matter what it may be, i.e., whether it pertains to the essence of the singulars or not. For since we find that Socrates and Plato and many others are without difference as to whiteness, we take this one item, namely, white, as a universal which is an accident. Similarly, because we find that Socrates and Plato and the others are not different as to rationality, this one item in which they do not differ, namely, rational, we take as a universal which is an essential difference.
lib. 2 l. 20 n. 14 Qualiter autem hoc unum accipi possit, manifestat consequenter. Manifestum est enim quod singulare sentitur proprie et per se, sed tamen sensus est quodammodo etiam ipsius universalis. Cognoscit enim Calliam non solum in quantum est Callias, sed etiam in quantum est hic homo, et similiter Socratem in quantum est hic homo. Et exinde est quod tali acceptione sensus praeexistente, anima intellectiva potest considerare hominem in utroque. Si autem ita esset quod sensus apprehenderet solum id quod est particularitatis, et nullo modo cum hoc apprehenderet universalem naturam in particulari, non esset possibile quod ex apprehensione sensus causaretur in nobis cognitio universalis.	But how this one item can be taken he now explains. For it is clear that sensing is properly and per se of the singular, but yet there is some how even a sensing of the universal. For sense knows Callias not only so far forth as he is Callias, but also as he is this man; and similarly Socrates, as he is this man. As a result of such an attainment pre-existing in the sense, the intellective soul can consider man in both. But if it were in the very nature of things that sense could apprehend only that which pertains to particularity, and along with this could in no wise apprehend the nature in the particular, it would not be possible for universal knowledge to be caused in us from sense-apprehension.
Et hoc idem manifestat consequenter in processu qui est a speciebus ad genus. Unde subdit quod iterum in his, scilicet in homine et equo, anima stat per considerationem quousque perveniatur ad aliquid impartibile in eis, quod est universale. Ut puta consideramus tale animal et tale, puta hominem et equum, quousque perveniamus ad commune animal, quod est genus; et in hoc similiter facimus quousque perveniamus ad aliquod genus superius. Quia igitur universalium cognitionem accipimus ex singularibus, concludit manifestum esse quod necesse est prima universalia principia cognoscere per inductionem. Sic enim, scilicet per viam inductionis, sensus facit universale intus in anima, in quantum considerantur omnia singularia.	Then he manifests this same point in the process which goes from species to genus. Hence he adds: “Again in these,” namely, in man and horse, “the mind lingers in its consideration, until it attains to some thing indivisible in them, which is universal.” For example, we consider such an animal and another one, say a man and a horse, until we arrive at the common item, “animal,” which is universal; and in this genus we do the same until we arrive at some higher genus. Therefore, since we take a knowledge of universals from singulars, he concludes that it is obviously necessary to acquire the first universal principles by induction. For that is the way, i.e., by way of induction, that the sense introduces the universal into the mind, inasmuch as all the singulars are considered.
lib. 2 l. 20 n. 15 Deinde cum dicit: quoniam autem eorum etc., solvit primas duas quaestiones, utrum scilicet primorum principiorum sit scientia, vel aliquis alius habitus. Circa quod ex praemissis accipit quod cognitio principiorum pertinet ad intellectum, cuius est cognoscere universale: nam universale dicit esse principium scientiae. Circa intellectum autem sunt duo genera habituum habentium se aliqualiter ad verum. Quidam enim sunt semper veri, alii vero interdum recipiunt falsitatem, ut patet de opinione et ratiocinatione, quae potest esse et veri et falsi. Sunt etiam et quidam habitus erronei, se habentes ad falsum. Quia vero principia sunt maxime vera, manifestum est quod non pertinent ad habitus qui semper sunt falsi, neque etiam ad habitus qui interdum recipiunt falsitatem, sed solum ad habitus qui sunt semper veri. Huiusmodi autem sunt scientia et intellectus. Additur autem in VI Ethic. tertium, scilicet sapientia: sed quia sapientia, ut ibidem dicitur, comprehendit in se scientiam et intellectum (est enim quaedam scientia et caput scientiarum), hic eam praetermittit. Hac ergo praetermissa, nullum aliud genus cognitionis quam intellectus, est certius scientia.	Then (1005) he solves the first two question, namely, whether the knowledge of first principles is science, or some other habit. In regard 1 to this he accepts, from what has been stated above, that the knowledge... of principles pertains to the intellect whose function is to know the universal: for he says that the universal is a principle of science. But in regard to the intellect there are two genera of habits, and these are not related to the true in exactly the same way. For some are always true, whereas others sometimes receive what is false, as in opinion and in those cases of reasoning which can be of the true and of the false. Again, there are certain erroneous habits, namely, which bear on the false. But because principles are most true, it is clear that they do not pertain to habits which are always of the false, or even to habits which now and then receive falsity, but only to habits which are always of the true. But these are science and understanding [i.e., intuition]. (In Ethics VI a third one is added, namely, wisdom: but because wisdom, as it is stated there, comprehends within itself both science and understanding—since it is a science and the chief of the sciences—he omits it here). Therefore, leaving this one aside, no other genus of knowledge but understanding is more certain than science.
Manifestum est autem quod principia demonstrationum sunt notiora conclusionibus demonstratis, ut in primo habitum est. Non autem potest esse scientia ipsorum principiorum, quia omnis scientia fit ex aliqua ratiocinatione, scilicet demonstrativa, cuius sunt principia illa de quibus loquimur. Quia igitur nihil potest esse verius quam scientia et intellectus (nam sapientia in his intelligitur), consequens est ex consideratione praemissorum quod principiorum proprie sit intellectus.	Now it is plain that the principles of demonstrations are better known than the demonstrated conclusions, as was established in Book I. Moreover, it cannot be through science that we have those principles, because science is the result of reasoning, namely, demonstrative, whose principles are the very things about which we are speaking. Therefore, because nothing can be truer than science and understanding (for wisdom is included in them), what follows from our consideration of the foregoing is that, properly speaking, the knowledge of principles is understanding.
Probat hoc etiam alia ratione, quia scilicet demonstratio non est ex necessitate demonstrationis principium; alioquin procederetur in demonstrationibus in infinitum, quod in primo improbatum est. Cum igitur demonstratio scientiam causet, sequitur quod neque scientia possit esse principium scientiae, ita scilicet quod principia scientiarum per scientiam cognoscantur. Si igitur nullum aliud genus cognitionis praeter scientiam habemus quod semper sit verum, relinquitur quod intellectus erit principium scientiae, quia scilicet per intellectum cognoscuntur principia scientiarum; ita scilicet quod hic intellectus, qui est principium scientiae, est cognoscitivus principii, ex quo procedit scientia. Hoc autem, scilicet scientia, est omne, idest totum, quod similiter se habet ad omnem rem, idest ad totam materiam de qua est scientia, sicut scilicet intellectus ad principium scientiae.	He also proves this with another reason, namely, because a demonstration is not”of necessity a principle of a demonstration; otherwise there would be an infinite process in demonstrations, and this was disproved in Book I. Since, therefore, demonstration causes science, it follows that science cannot be the principle of science, as though the principles of the sciences were made known through science. Therefore, if we have no other type of knowledge except science which is always true, it follows that understanding will be the principle of science, namely, because the principles of the sciences are made known through understanding, so far forth, namely, that this understanding which is the principle of science is cognoscitive of the principles from which science proceeds. But this, namely, science, is all, i.e., a whole, which is related to every thing (i.e., to the entire matter with which science is concerned) in the way that understanding is related to the principles of science.