Authors/Thomas Aquinas/metaphysics/liber7/lect15

Lecture 15

Latin	English
lib. 7 l. 15 n. 1 In hoc loco philosophus ostendit, quod ideae quae ponuntur separatae a Platonicis, non possunt definiri. Et hoc ideo, quia Platonici ad hoc praecipue ponebant ideas, ut eis adaptarentur et definitiones et demonstrationes, quae sunt de necessariis, cum ista sensibilia videantur omnia in motu consistere. Et circa hoc duo facit. Primo ostendit per rationes, quod ideae non possunt definiri. Secundo per signum, ibi, quoniam propter quid nullus. Circa primum ponit tres rationes: quarum primam ponit sic dicens, quod substantiarum alia est sicut ratio, idest sicut quod quid erat esse et forma, et alia est sicut compositum ex materia et forma, quod est totum simul coniunctum ex materia et forma. Dico autem eas esse alteras quia hoc quidem, scilicet substantia, quae est totum, sic est substantia sicut habens rationem conceptam cum materia; illa vero, quae est sicut forma et ratio et quod quid erat esse, est totaliter ratio et forma non habens materiam individualem adiunctam.	1606. In this place the Philosopher shows that the Ideas, which the Platonists claimed to be separate, are incapable of being defined. And he does this because the Platonists posited Ideas chiefly in order that they might apply them both to definitions and demonstrations, which have to do with what is necessary, since all these sensible substances seemed to be in motion. In regard to this he does two things. First (669)C 1606), he uses arguments to show that the Ideas cannot be defined. Second (676:C 1627), he uses an example (“Therefore, as was stated”). In the first member of this division (669) he presents three arguments, and the first of these he states as follows: one kind of substance is “the intelligible structure,” i.e., the essence and form, and another is the composite of matter and form, which is the concrete whole made up of matter and form. And I say that these differ; i.e., “that the latter,” which is substance in the sense of the concrete whole, is substance taken as something having its intelligible structure conceived with matter; but the former, which is the form or intelligible structure or essence of a thing, is the intelligible structure or form in general, and this does not have individual matter connected with it.
lib. 7 l. 15 n. 2 Quaecumque igitur dicuntur substantiae hoc modo sicut composita, eorum potest esse corruptio. Ostensum est enim supra, quod eorum solum est generatio, quae ex materia et forma componuntur. Corruptio autem et generatio sunt circa idem.	1607. Therefore all those things which are called substance in the sense of a composite are capable of being corrupted; for it was shown above (611)C 1423) that only those things which are composed of matter and form are subject to generation; and generation and corruption belong to the same subject.
lib. 7 l. 15 n. 3 Ipsius autem substantiae, quae est sicut ratio vel quod quid est, non est ita corruptio quod ipsa per se corrumpatur. Ostensum est enim supra quod non est eius generatio, sed solum compositi; non enim fit quod quid erat esse domui, ut supra ostensum est, sed fit quod est proprium huic domui. Generatur enim haec domus particularis, non autem ipsa species domus. Sed tamen huiusmodi formae et quidditates aliquando sunt, et aliquando non sunt sine generatione et corruptione, idest sine hoc quod ipsa generentur vel corrumpantur per se, sed incipiunt esse et non esse aliis generatis et corruptis. Ostensum est enim supra quod nullus in naturalibus generat haec, scilicet formas et quidditates, nec etiam in artificialibus; sed hoc agens singulare generat et facit hoc singulare.	1608. And substance in the sense of the intelligible structure or whatness of a thing is incapable of being corrupted in such a way that it is corrupted in itself. For it was shown above (611)C 1417-23) that this kind of substance is not generated but only the composite; for it is not the essence of a house that is produced (as was shown above), but what is peculiar to this house; because it is this particular house and not the intelligible structure of a house that is produced. Yet forms and quiddities of this kind sometimes are and sometimes are not “without generation and corruption,” i.e., without being generated or corrupted in themselves, for they begin to be and not to be when other things are generated and corrupted. For it was shown above (611:C 1420) that in the case of natural things no one “generates these,” namely, their forms and quiddities; nor does this happen even in the case of artificial things; but this singular agent generates and produces this singular thing.
lib. 7 l. 15 n. 4 Propter hoc autem, quod singularia generantur et corrumpuntur, substantiarum sensibilium singularium non potest esse nec definitio nec demonstratio. Habent enim materiam individualem; cuius natura est talis, ut id quod ex ea constituitur, contingat esse et non esse; quia ipsa materia quantum est in se, est in potentia ad formam, per quam res materialis est, et ad privationem per quam res materialis non est. Et ideo omnia singularia de numero ipsorum sensibilium, quorum materia est in potentia ad esse et non esse, sunt corruptibilia. Corpora tamen caelestia non habent materiam huiusmodi, quae sit in potentia ad esse et non esse, sed solum ad ubi. Et ideo non sunt corruptibilia.	1609. And because singular things are generated and corrupted there can be neither definition nor demonstration of singular sensible substances; for they contain individual matter whose nature is such that anything constituted of it is capable both of being and of not being. For matter itself, considered in itself, is in potentiality to form, by means of which the material thing exists, and to privation, by reason of which the material thing does not exist. Hence all singular things included among these sensible substances whose matter is in potentiality to being and non-bcing are corruptible. However, the celestial bodies do not have that kind of matter which is in potentiality to being and non-being, but that which is in potentiality to place; therefore they are not corruptible.
lib. 7 l. 15 n. 5 Si ergo demonstratio est necessariorum, ut probatum est in posterioribus, et definitio etiam est scientifica, idest faciens scire, quae est quasi medium demonstrationis, quae est syllogismus faciens scire; sicut non contingit quandoque esse scientiam et quandoque ignorantiam, quia quod scitur semper oportet esse verum, sed id quod est tale, idest quod quandoque potest esse verum, quandoque falsum, est opinio; ita etiam non contingit demonstrationem nec definitionem esse eorum quae possunt se aliter habere; sed solum opinio est huiusmodi contingentium.	1610. Hence, if demonstration is of necessary things, as was proved in the Posterior Analytics, and definition is also “scientific,” i.e., productive of science, because it serves as the middle term in a demonstration, which is a syllogism producing science, then just as it is impossible for scientific knowledge sometimes to be scientific knowledge and sometimes ignorance, because what is known scientifically must always be true, “but what is such,” i.e., what can sometimes be true and sometimes false, is opinion, in the same way it is impossible that there should be demonstration or definition of those things which can be otherwise than they are; but about contingent things of this kind there is only opinion.
lib. 7 l. 15 n. 6 Si, inquam, ita est, palam est, quod non erit nec definitio nec demonstratio ipsorum singularium corruptibilium sensibilium. Non enim huiusmodi corruptibilia possunt esse manifesta scientiam habentibus de eis, scilicet cum recesserunt a sensu, per quem cognoscuntur. Et ideo salvatis eisdem rationibus in anima ipsorum singularium, idest speciebus, per quas cognosci possunt, non erit de eis nec definitio nec demonstratio. Et propter hoc oportet, cum aliquis eorum, qui student ad assignandum terminum, idest definitionem alicuius rei, definiat aliquod singulare, quod non ignoret, quia semper contingit auferre singulare, manente tali ratione, quam ipse fingit in anima. Et hoc ideo quia non contingit vere definire singulare. In his enim quae vere definiuntur, manet cognitio definiti quamdiu manet cognitio definitionis in anima.	1611. If this is so, I say, it is evident that there will be neither definition nor demonstration of these singular, sensible, corruptible things. For corruptible things of this kind cannot be clearly known by those who have scientific knowledge of them when they have passed outside the scope of the senses, through which they are known. Hence, “even though the intelligible expressions” or forms of these singular things, by which they can be known, “remain in the soul,” there will be neither definition nor demonstration of them. And for this reason when anyone, “eager for setting the limits of things,” i.e., the definition of anything, defines a singular thing, he must not ignore the fact that it is always possible to remove the singular while the intelligible expression as such which he forms in his mind remains. And this is true because it is impossible to give a genuine definition of a singular; for in the case of those things which are truly defined the knowledge of the thing defined remains as long as the knowledge of the definition remains in the mind.
lib. 7 l. 15 n. 7 Si igitur singulare definiri non potest, itaque nec ideam possibile est definire. Ideam enim oportet esse singularem, secundum ea quae ponuntur de idea. Ponunt enim quod idea est quoddam per se existens ab omnibus aliis separatum. Haec autem est ratio singularis.	1612. Therefore, if a singular thing cannot be defined, it is impossible to define an Idea; for an Idea must be a singular thing, according to those who posit Ideas, since they claim that an idea is something which subsists of itself apart from all other things; and this is what singular thing means.
lib. 7 l. 15 n. 8 Deinde cum dicit necessarium vero ponit secundam rationem: et circa hoc duo facit. Primo ponit rationem. Secundo excludit quamdam cavillosam responsionem, ibi, si quis autem dicat. Fuit autem necessarium ut hanc rationem superadderet rationi suprapositae, quia ratio iam posita probabat singulare non esse definibile, ex eo quod est corruptibile et materiale; quae duo Platonici ideis non attribuebant. Unde ne per hoc sua probatio inefficax redderetur, subiungit aliam rationem, dicens:	1613. And it is necessary (670). Then he gives the second argument; and in regard to this he does two things. First, he gives the argument; and second (671:C 1619), he rejects an answer which avoids the question (“But if”). Now it was necessary that he should add this argument to the foregoing one, since the argument given has already proved that the singular is not definable because it is corruptible and material, and the Platonists did not assign these two properties to the Ideas. Hence, lest his proof should be rendered ineffective, he adds another argument (670), and states it as follows.
lib. 7 l. 15 n. 9 Necessarium esse omnem definitivam rationem esse ex pluribus nominibus. Ille enim qui definit, non faciet notificationem rei ponendo unum nomen tantum; quia si poneret unum tantum nomen, adhuc definitum remanebit nobis ignotum. Contingit enim uno nomine notiori assignato, ipsum nomen definiti notificari; non autem rem definitam, nisi principia eius exprimantur, per quae res omnis cognoscitur.	1614. It is necessary that every definitive expression should be composed of several words; for one who defines a thing does not convey its meaning by giving only one word, because if he were to give only one the thing defined would still remain unknown to us. For when a single better known word is given it is possible to know the name of the thing defined but not the thing defined, unless its principles are given; for it is by its principles that everything becomes known.
lib. 7 l. 15 n. 10 Resolutio autem definiti in sua principia, quod definientes facere intendunt non contingit nisi pluribus nominibus positis. Et ideo dicit, quod si unum nomen tantum ponatur, quod adhuc remanebit definitum ignotum; sed si plura ponantur, oportet quod nomina posita sint communia omnibus.	1615. Now the resolving of the thing defined into its principles—which those forming definitions intend to do—is possible only when several words are given. Therefore he says that, if only one word is given, the thing defined will still remain unknown; but if many words are given, they must be common to all things [of their class].
lib. 7 l. 15 n. 11 Si enim in definitione alicuius singularis ponantur aliqua nomina quae conveniunt ipsi soli, erunt synonyma nomina unius rei singularis; unde res non notificabitur huiusmodi nominibus positis, sed forte nomen minus notum. Sicut si diceremus quid est Tullius, et responderetur Marcus et Cicero non esset conveniens definitio.	1616. For if in the definition of any singular thing certain words are given which are proper only to that thing itself, they will be synonymous names of the same singular thing. Hence it is not the thing which will be made known when words of this kind are given, but perhaps a less well known word. For example, if we were to ask who Tullius is, and one were to answer, Marcus and Cicero, it would not be an apt definition.
lib. 7 l. 15 n. 12 Oportet igitur, si singulare definitur, in eius definitione poni aliqua nomina, quae multis conveniant. Ergo necesse erit, quod definitio non solum huic singulari conveniat, cuius definitio quaeritur, sed etiam aliis. Quod est contra rationem verae definitionis. Sicut si aliquis te definire intendat, et dicat quod tu es animal gressibile, aut animal album, vel quicquid aliud, non tibi soli convenit, sed etiam est in alio.	1617. Therefore, if a singular thing is defined, certain words must be given which are applicable to many things. Hence the definition must fit not only the singular thing whose definition is under investigation but also other things; and this is opposed to the notion of a true definition; for example, if someone intended to define you, and said that you are an animal capable of walking or a white animal or anything else that applies to you, this definition would not only fit you but other things as well.
lib. 7 l. 15 n. 13 Unde patet, quod singulare, non solum ex hoc quod est corruptibile et materiale, caret definitione, sed etiam ex hoc quod est singulare; unde nec idea definitur. Cuius ratio est quam hic tangit philosophus: quia si nomina ad definiendum assumpta exprimunt individuum quantum ad ea ex quibus individuatur, erunt nomina synonyma. Si autem exprimunt naturam et accidentia communia absque individuatione, non erit definitio propria definitio: quia omnes formae, sive accidentales, sive substantiales, quae non sunt per se subsistentes, sunt, quantum est de se, communes multis. Et si aliqua inveniatur in uno solo, sicut forma solis, hoc non provenit ex parte formae, quin quantum est de se sit nata esse in pluribus; sed ex parte materiae. Nam tota materia speciei congregata est sub uno individuo. Vel magis ex parte finis; quia unus sol sufficit ad universi perfectionem.	1618. It is evident, then, that a singular thing lacks a definition not only because it is corruptible and material but also because it is singular. Hence, neither is an Idea defined. The reason for this is the one which the Philosopher gives here: if the words taken to define a thing express the individual in terms of the things by which it is individuated, the words will be synonymous. But if they express the nature and common attributes without individuation, the definition will not be a proper definition of the thing defined, because all forms, accidental or substantial, which do not subsist of themselves, are, when considered in themselves, common to many. And if some are found in only one thing, as the form of the sun, this does not come from the form, inasmuch as it is of itself suited to be in many things, but from the matter; for the whole matter of the species is collected in one individual. Or this comes from its final cause, because one sun is sufficient for the perfection of the universe.
lib. 7 l. 15 n. 14 Deinde cum dicit si quis autem excludit quamdam cavillosam responsionem. Posset enim aliquis dicere, quod licet quodlibet eorum, quae ponuntur in definitione singularis ideae, conveniat separatim multis, non tamen simul accepta conveniunt nisi uni soli; huic scilicet cuius definitio quaeritur. Hanc autem responsionem excludit duobus modis. Primo quantum ad ipsas ideas. Secundo quantum ad ea, quorum sunt ideae, ibi, amplius de multis. Circa primum duo facit. Primo excludit responsionem praedictam; ostendens quod adhuc sequitur definitionem non definito soli inesse. Secundo quod non primo, ibi, et necesse esse priora. Dicit ergo, quod contra responsionem praedictam, primo est dicendum hic, quod definitio assignata alicui ideae etiam aliis inerit; sicut si definitio ideae hominis sit animal bipes, haec duo inerunt animali et bipedi, idest ideae animalis et ideae bipedis; quia etiam illae duae ideae simul coniunctae erunt animal bipes. Et sic haec definitio, animal bipes, non erit propria ideae hominis. Et hoc inconveniens quidem accidit in sempiternis, idest considerando etiam definitionem ideae, quae est quoddam singulare sempiternum secundum Platonicos; et considerando quod definitio assignata uni ideae convenit aliis.	1619. But if anyone (671). Then he rejects an answer which is evasive. For someone could say that while any of those attributes given in the definition of a singular Idea are proper to many individually, yet taken together they are proper to only one thing, viz., to the one whose definition is under investigation. He rejects this answer in two ways. First (671:C 1619), with reference to the Ideas themselves; and second (675:C 1624), with reference to those things of which they are the Ideas (“It will, moreover”). In regard to the first he does two things. First, he rejects the answer mentioned above, showing that it still does not follow that the definition belongs only to the thing defined; and second (672:C 1620), that it does not belong to it primarily (“It is also necessary”). Hence he says (671) that in opposing this answer it must be said, first, that the definition assigned to any Idea also belongs to other Ideas; for example, if the definition of the Idea of man is two-footed animal, these two belong “to animal and to two-footed,” i.e., to the Idea of animal and to the Idea of two-footed; for those two Ideas combined would also be two-footed animal. Hence this definition, two-footed animal, will not be proper to the Idea of man. And this absurdity also follows ,,in the case of eternal things,” i.e., if we consider the definition of an Idea, which is an eternal singular, from the Platonists’ point of view, and if we consider that the definition given to one Idea is proper to the others.
lib. 7 l. 15 n. 15 Deinde cum dicit et necesse ostendit quod sequitur ulterius, quod definitio assignata ideae hominis non primo convenit ei; quod est contra rationem definitionis. Nam definitio primo verificatur de definito. Hoc autem ostendit tribus modis. Primo sic: dicens, quod non solum necesse est quod animali et bipedi conveniat definitio assignata homini; sed etiam necesse est quod illa, scilicet animal et bipes, existant priora homine, et sint partes eius, inquantum homo ex utroque constituitur.	1620. It is also (672). Then he exposes the second consequence, namely, that the definition assigned to the Idea of rnan does not belong primarily to this Idea; and this is opposed to the notion of a definition, for a definition is shown to be true primarily of the thing defined. He proves this in three ways. First, he says that it is necessary not only that the definition given to man should belong to animal and to two-footed, but also that these—animal and two-footed—should be prior to man and be his parts inasmuch as man is composed of both.
lib. 7 l. 15 n. 16 Quinimmo secundum positionem eorum sequeretur, quod ambo sint separabilia ab homine, et ab aliis animalibus, scilicet animal et bipes, si homo ponitur separabilis ab individuis. Sicut enim homo est superius ad individua, ita genus et differentiae ad hominem. Aut enim oportet quod nullum commune sit separabile; aut oportet quod ambo praedicta, scilicet animal et bipes, sint separabilia ab homine. Si igitur nullum commune est separabile, tunc sequetur quod genus non erit praeter species. Et sic genus non significabit substantiam. Si vero genus erit praeter species, pari ratione et differentia, quae etiam est communior specie. Si autem utraque, scilicet animal et bipes, sunt separabilia ab homine, sequetur quod sint priora, eo modo sicut homo separatus est prior individuis. Et ita sequetur ulterius, quod definitio assignata homini, conveniat quibusdam prioribus, scilicet animali et bipedi.	1621. But according to the position of the Platonists it would rather follow that both of these—animal and two-footed—are separable from man and from other animals, if man is assumed to be separable from individuals; because just as man is above individuals, in a similar fashion genus and difference are above man. For it is necessary either that nothing common be separable, or that both of these—animal and two-footed—be separable from man. Now if nothing common is separable, it follows that a genus will not exist apart from its species, and thus the genus will not signify substance. But if a genus exists apart from its species, then for a like reason a difference will also exist apart, for this is more common than a species. But if both animal and two-footed are separable from man, it follows that they are prior in the way in which the separate man is prior to the individual. And thus it further follows that the definition assigned to man belongs to certain prior things-to animal and to two-footed.
lib. 7 l. 15 n. 17 Secundo ibi, deinde quia ostendit idem alia ratione; dicens, quod inde patet quod animal et bipes sunt priora homine secundum esse. Ista enim sunt priora in esse quae non removentur aliis ablatis; sed eis ablatis alia removentur. Sicut unum est prior duobus, quia remoto uno, removentur duo, sed non e converso. Remotis autem animali et bipede, removetur homo; sed remoto homine, hoc, scilicet animal et bipes, non aufertur. Unde patet quod animal et bipes sunt priora homine.	1622. Again, because (673). Second, he proves the same point by means of another argument. He says that it is evident from the following consideration that animal and two-footed are prior to man in being; for those things are prior in being which are not destroyed when other things are destroyed, although when they are destroyed other things are destroyed. For example, the number one is prior to the number two because, when the number one is destroyed, the number two is destroyed; but not the reverse. And when animal and two-footed are destroyed, man is destroyed, although when man is destroyed the former—animal and two-footed—are not destroyed. Hence animal and two-footed are evidently prior to man.
lib. 7 l. 15 n. 18 Tertio ibi, deinde autem ostendit idem tertia ratione; dicens, quod idem apparet si ponamus animal et bipes non solum esse separabilia ab homine, quasi quaedam ideae eius, sicut supra dictum est in prima ratione, sed etiam quod ex ipsis fit homo, ut sic ex ideis separatis fiat idea separata. Patet enim, quod minus erunt composita animal et bipes, ex quibus componitur homo, quam homo qui componitur ex eis. Quod autem est minus compositum, est prius. Unde sequetur adhuc, quod animal et bipes sunt priora homine, non solum propter separationem, ut prima ratio procedebat, sed etiam propter compositionem, ut procedit haec tertia ratio.	1623. And again (674). He then proves the same point by a third argument. He says that the same conclusion is evident if we maintain not only that animal and two-footed are separable from man, as being Ideas of man, as was proved above in the first argument (671:C 1621), but also that man is composed of them, insomuch that in this way a separate Idea turns out to be composed of separate Ideas. For it is evident that animal and two-footed, of which man is composed, would be less composite than man, who is composed of them. But what is less composite is prior. Hence it follows again that animal and two-footed are prior to man, not only because they are separate, as the first argument advanced, but also because man is composite, as this third argument advanced.
lib. 7 l. 15 n. 19 Deinde cum dicit amplius de multis ponit aliam rationem ad excludendum praemissam responsionem; dicens, quod non solum sequetur quod definitio assignata ideae hominis conveniat aliis ideis prioribus, scilicet animali et bipedi, ex quibus ponitur constitui idea hominis; sed etiam illa ipsa, ut animal et bipes, oportebit praedicari de multis, et non de homine tantum, non solum seorsum accepta, ut praemissa responsio istorum dicebat, sed etiam coniunctim.	1624. It will, moreover (675). Then he gives an additional argument to reject the answer given above. He says that it not only follows that the definition assigned to the Idea of man is common to other prior Ideas, namely, to animal and to two-footed, of which the Idea of man is supposed to be composed, but also that these very things—animal and two-footed—will be predicated of many things and not just of man. And this will occur not only when they are taken in themselves, as the foregoing answer of these men stated, but also when they are taken together.
lib. 7 l. 15 n. 20 Si enim haec ex quibus componitur idea hominis, scilicet animal et bipes, non praedicantur de multis, quomodo cognoscetur quod sint ideae hominis, ut supra conclusum est? Sequetur enim quod sit aliqua idea, quae non potest praedicari de pluribus quam de uno. Constat enim quod idea animalis de pluribus numero praedicari potest. Si ergo haec duo simul animal bipes, non possunt praedicari nisi de uno, sequetur quod bipes restringat animal ad unum, ita quod aliqua idea quae est bipes praedicetur de uno tantum. Quod non videtur esse verum; cum omnis idea sit participabilis a multis. Ab uno enim exemplari, multa exemplaria fieri contingit. Non igitur praedicta responsio potuit esse vera.	1625. For if these elements of which the Idea of man is composed, animal and two-footed, are not predicated of many things, how is it known that they belong to the Idea of man, as was concluded above (644)C 1542-50)? For it would follow that there is some Idea which cannot be predicated of more things than one, since it is evident that the Idea of animal can be predicated of many individuals. Hence, if these two together—animal and two-footed—can be predicated of only one thing, it follows that two-footed restricts animal to one thing so that some Idea, two-footed, is predicated of only one thing. But this does not seem to be true, since every Idea is capable of being participated in by many things; for from one exemplar there arise many things which resemble that exemplar. Therefore the foregoing answer cannot be true.
lib. 7 l. 15 n. 21 Sciendum est autem quod per hanc eandem rationem sufficienter ostenditur etiam nullum singulare in his inferioribus definiri posse per aliquas proprietates vel formas adunatas, quaecumque fuerint. Sicut enim quaelibet idea, ita et quaelibet forma, quantum est de se, nata est in pluribus esse. Et ita, quantumcumque aggregentur, non erit certa assignatio huius singularis nisi per accidens, inquantum contingit omnia insimul collecta in uno solo inveniri. Unde patet quod collectio accidentium non est principium individuationis, ut quidam dicunt, sed materia designata, ut philosophus dixit.	1626. Moreover, it must be understood that by the same argument it can also be adequately shown that no singular thing among these sensible things can be defined by any properties or united forms, whatever they may be. For any Idea, and also any form, taken in itself, is naturally disposed to exist in many things; and thus no matter how they may be combined there will be an exact definition of this singular thing only accidentally, inasmuch as it is possible for all of these forms taken together to be found in only one thing. It is obvious, then, that the principle of individuation is not a collection of accidents (as some said), but designated matter, as the Philosopher has stated (627:C 1496).
lib. 7 l. 15 n. 22 Deinde cum dicit quemadmodum ergo ponit tertiam rationem principalem ad ostendendum quod ideae non possunt definiri; dicens, quod quia supra dictum est, quod individua non possunt definiri propter hoc quod sunt corruptibilia, ut prima ratio procedebat, et quia ea quae accipiuntur in definitionibus sunt communia, ut procedebat ratio secunda, latet verum esse hoc quod dictum est, scilicet quod impossibile sit definire singularia in sempiternis, et maxime in illis quae sunt unica in una specie, sicut sol et luna. Quia enim sunt sempiterna, non videtur de eis concludere ratio, quae ex corruptione singularium procedebat. Quia vero sunt unica in una specie, non videtur de eis ratio concludere quae procedebat ex communitate partium definitionis. Quaecumque enim convenit soli speciei, conveniunt soli individuo.	1627. Therefore, as was stated (676). Then he gives the third and chief argument to show that Ideas cannot be defined. He says that, since it has been stated above (669:C 1609) that individuals cannot be defined because of their corruptibility, as the first argument advanced, and since those attributes which are included in definitions are common ones, as the second argument advanced, the truth of the statement that it is impossible to define singulars among eternal things is not apparent, especially in the case of those which are unique in one species, as the sun and the moon. For since the things in question are eternal, the argument based on the corruptibility of singular things does not seem to be conclusive when applied to them. And because these things are unique in their species, the argument from the commonness of the parts of a definition does not seem to be conclusive in their regard; for in this case all attributes proper to one species alone are proper to one individual alone.
lib. 7 l. 15 n. 23 Sed pro tanto decipiuntur, qui putant haec esse definibilia, quia definientes talia peccant multipliciter. Et uno modo peccant inquantum addunt aliqua in definitionibus eorum, quibus ablatis adhuc erunt ipsa, scilicet sol et luna. Sicut cum definiendo solem, dicunt quod est perigyrion, idest terram gyrans, aut nycticrypton, idest nocte absconsum. Si enim sol steterit non gyrans terram, aut si apparuerit, ut non sit nocte absconsum, non adhuc erit sol, si bene fuerit definitum. Sed absurdum est, si non sit sol istis remotis. Sol enim significat quamdam substantiam; illa vero, per quae definitur, sunt quaedam accidentia eius.	1628. But those who think that these things are definable are deceived to such an extent that they make many errors in defining such things. They err in one respect inasmuch as they add in the definitions of these things such attributes as can be removed and let the things themselves remain, namely, the sun and the moon; for example, in defining the sun they say that it is something “going around the earth,” i.e., revolving around the earth, or “hidden at night,” i.e., invisible during the night. For if the sun were to stand still and not revolve around the earth, or if it appeared without being invisible at night, it would not be the sun if it had been defined properly. However, it would be absurd if it were not the sun when these attributes were removed, for the sun signifies a substance; but these things by which it is defined are certain of its accidents.
lib. 7 l. 15 n. 24 Non solum autem sic peccant, sed et amplius, definientes solem per aliquid quod convenit in alio esse. Si enim fiat alter talis, idest aliquod corpus habens talem vel eamdem formam et speciem, palam est quod erit sol, secundum quod sol significat speciem, et hoc modo potest definiri. Ratio autem definitiva est communis, idest huius speciei quod est sol. Sed sol iste erat de numero singularium, sicut Cleon aut Socrates. Et sic patet, quod licet etiam ideae ponantur sempiternae et unicae in una specie, adhuc non poterunt definiri.	1629. And they not only err in this way but also make a further mistake when they define the sun by an attribute which is suited to belong to something else; for supposing that “another such thing should come into being,” i.e., some body having such a form, or the same form and species, it is evident that it would be a sun, inasmuch as sun signifies a species; and in this way it can be defined. Hence, “the definitive expression is common,” i.e., the intelligible expression of the species sun. But this sun would be a singular thing like Cleon or Socrates. Thus it is certain that even though the Ideas are also claimed to be eternal and unique in their species, they still cannot be defined.
lib. 7 l. 15 n. 25 Quare nullus ponentium ideas protulit aliquem terminum, idest definitionem ideae. Si enim aliqua definitio ab eis data esset de aliqua idea, puta hominis vel equi, fieret manifestum contra tentantes definire ideam, quia verum est quod modo dictum est, scilicet quod idea est indefinibilis.	1630. Hence none of those who posit Ideas reveal “any fixed limits,” i.e., definition, of an Idea. For if they were to give the definition of some Idea, as that of man or horse, it would become evident, in opposition to those attempting to define an Idea, that what has just been said is true: an Idea is indefinable.