Authors/Thomas Aquinas/physics/L5/lect2

Lecture 2 The species of change; which one is motion

Latin	English
	Lecture 2 The species of change; which one is motion
lib. 5 l. 2 n. 1 Postquam philosophus distinxit motum per se a motu per accidens, hic dividit mutationem et motum per se in suas species. Ubi considerandum est quod Aristoteles supra in tertio ubi motum definivit, accepit nomen motus secundum quod est commune omnibus speciebus mutationis. Et hoc modo accipit hic nomen mutationis: motum autem accipit magis stricte, pro quadam mutationis specie. Dividitur ergo pars ista in partes duas: in prima dividit mutationem in suas species, quarum una est motus; in secunda subdividit motum in suas species, ibi: si igitur praedicamenta et cetera. Circa primum duo facit: primo ponit divisionem mutationis; secundo manifestat partes divisionis, ibi: ex non subiecto quidem et cetera. Circa primum tria facit: primo praemittit quaedam necessaria ad divisionem mutationis; secundo concludit ex praemissis mutationis divisionem, ibi: quare necesse est etc.; tertio excludit quandam obiectionem, ibi: quae enim est ex non subiecto et cetera.	649. After distinguishing per se from per accidens motion, the Philosopher now divides per se change and motion into its species. Here it should be noted that in Book III when Aristotle defined motion, he took it as being common to all species of change. It is in this sense that he now uses the word “change”. And he is beginning to use the word “motion” in a stricter sense, i.e., for a certain species of change. Therefore, this section is divided into two parts: In the first he divides change into its various species, of which one is motion; In the second he subdivides motion into its species, at L. 3. About the first he does two things: First he gives his division of change; Secondly, he explains the parts of the division, at 654. About the first he does three things: First he states certain things that must be mentioned before dividing change; Secondly, from these he concludes to the division of change, 651; Thirdly, he answers an objection at 652,
lib. 5 l. 2 n. 2 Dicit ergo primo quod cum omnis mutatio sit a quodam in quiddam, ut manifestatur ex ipso mutationis nomine, quod denotat aliquid esse post aliud, et aliud esse prius et aliud posterius; necesse est his suppositis, quod omne quod mutatur, quatuor modis mutetur. Aut enim uterque terminus est affirmatus; et sic dicitur aliquid mutari ex subiecto in subiectum. Aut terminus a quo est affirmatus, et terminus ad quem est negatus; et sic dicitur aliquid moveri ex subiecto in non subiectum. Aut e converso terminus a quo est negatus, et terminus ad quem est affirmatus; et sic dicitur aliquid moveri ex non subiecto in subiectum. Aut uterque terminus est negatus; et sic dicitur aliquid mutari ex non subiecto in non subiectum. Non enim accipitur hic subiectum eo modo quo sustinet formam; sed omne illud quod affirmative significatur, dicitur hic subiectum.	650. He says therefore first (477 224 b35) that since every change is from something to something—as is clear from the very word “change” which denotes something after something else, i.e., something earlier and something later—it follows from all this that what changes must change in one of four ways. (1) For both termini might be affirmed, in which case something is said to be changed from subject to subject; or (2) the terminus a quo is affirmed and the terminus ad quem negated, in which case something is changed from subject to non-subject; or (3) on the other hand, the terminus a quo is negated and the terminus ad quem affirmed, in which case something is moved from non-subject to subject. Finally (4), both termini might be negated, in which case something is said to be changed from non-subject to non-subject. (Here the word “subject” is not taken in the sense of that which sustains a form; rather, anything that is affirmatively expressed is here called a “subject”.
lib. 5 l. 2 n. 3 Deinde cum dicit: quare necesse est etc., concludit ex praemissis divisionem mutationis. Et dicit quod necessario ex praemissis sequitur, quod tres sint mutationis species: quarum una est ex subiecto in subiectum, sicut cum aliquid mutatur de albo in nigrum; alia autem est ex subiecto in non subiectum, sicut cum aliquid mutatur de esse in non esse; tertia est e converso ex non subiecto in subiectum, sicut cum aliquid mutatur de non esse in esse.	651. Then at (478 225 a7) he derives from these premises his division of change. And he says that it necessarily follows from these premises that there are three kinds of change: one is from subject to subject, as when something is changed from white to black; another is from subject to non-subject, as when something is changed from being to non-being; the third is from non-subject to subject, as when something is changed from non-being to being,
lib. 5 l. 2 n. 4 Deinde cum dicit: quae enim est ex non subiecto etc., excludit quandam obiectionem. Posset enim aliquis obiicere, quod cum praemiserit quatuor modis aliquid mutari, debuisset concludere quatuor esse species mutationis, et non tres tantum. Sed hanc obiectionem excludit dicens, quod non potest esse aliqua mutationis species de non subiecto in non subiectum; quia omnis mutatio est inter opposita; duae autem negationes non sunt oppositae. Neque enim dici potest quod sint contraria, neque quod sint contradictoria. Et huius etiam signum est, quia quascumque negationes contingit simul esse veras de aliquo uno et eodem, sicut lapis nec est sanus nec aeger. Unde cum mutatio per se sit solum in contrariis et in contradictione, ut supra dictum est, sequitur quod ex negatione in negationem non sit mutatio per se, sed solum sic mutatur aliquid per accidens. Cum enim aliquid fit de albo nigrum, fit etiam per accidens de non nigro non album. Et per hunc modum dixit aliquid mutari ex non subiecto in non subiectum. Quod autem est per accidens in aliquo genere, non potest esse species illius generis. Et ideo ex non subiecto in non subiectum non potest esse aliqua mutationis species.	652. Then at (479 225 a10) he precludes a possible objection. For someone might object that since he mentioned four ways in which change can take place, he should have derived four kinds of change and not merely three. But he dismisses this objection by saying that there cannot be any kind of change from non-subject to non-subject, because every change takes place between opposites and two negations are not opposites. For they are neither contrary nor contradictory. A further proof of this is that any pair of negatives may chance to be true of one and the same thing at the same time; for example, a stone is neither healthy nor sick. Hence, since per se change occurs only between contraries and contradictories, as was pointed out above, it follows that there is no per se change from one negation to another. Such changes would always be per accidens, for when something changes from white to black, it changes at the same time, but per accidens, from non-black to non-white. This is the way that something is changed from non-subject to non-subject. However, what is per accidens in any genus cannot be a species of that genus. Therefore, there can be no species of change from non-subject to non-subject.
lib. 5 l. 2 n. 5 Deinde cum dicit: ex non subiecto quidem etc., manifestat partes positae divisionis. Et circa hoc tria facit: primo manifestat duas partes divisionis; secundo ostendit quod neutra earum est motus, ibi: si igitur quod non est etc.; tertio concludit quod residua pars divisionis est motus, ibi: quoniam autem motus et cetera. Circa primum duo facit: primo manifestat unam partem divisionis; secundo aliam, ibi: quae vero ex subiecto in non et cetera.	653. Then at (480 225 a12) he explains the parts used in his division. About this he does three things: First he explains the first two parts; Secondly, he shows that neither of them is motion, at 656; Thirdly, he concludes that the remaining part is motion, at 659. About the first he does two things,, First he explains one part of the division; Secondly, he explains a second part, at 655.
lib. 5 l. 2 n. 6 Dicit ergo primo quod illa mutatio quae est ex non subiecto in subiectum, est inter opposita secundum contradictionem, et vocatur generatio, quae est mutatio de non esse in esse. Sed haec est duplex: quaedam enim est simplex generatio, qua aliquid simpliciter generatur; alia vero est generatio quaedam, qua aliquid secundum quid generatur. Et ponit exemplum de utraque generatione. Et primo de secunda, dicens quod cum aliquid mutatur de non albo in album, est generatio huius et non simpliciter. Et secundo de prima; et dicit quod illa generatio, quae est ex non esse simpliciter in ens quod est substantia, est generatio simpliciter, secundum quam simpliciter dicimus aliquid fieri et non fieri. Cum enim generatio sit mutatio de non esse in esse, secundum illum modum dicitur aliquid generari, quo ex non esse in esse mutatur. Cum autem ex non albo fit album, non mutatur aliquid ex non esse simpliciter in esse simpliciter. Quod enim mutatur proprie, subiectum est; subiectum autem albi est aliquod ens actu. Unde cum subiectum maneat in tota mutatione, etiam in principio mutationis erat ens actu, simpliciter loquendo; non tamen erat ens actu hoc, scilicet album: et ideo non dicitur fieri simpliciter sed fieri hoc, scilicet album. Subiectum vero formae substantialis non est aliquod ens actu, sed ens in potentia tantum, scilicet materia prima, quae in principio generationis est sub privatione, in fine autem sub forma: et ideo secundum generationem substantiae fit aliquid simpliciter. Et ex hoc haberi potest, quod secundum nullam formam quae praesupponit aliam formam in materia, attenditur generatio simpliciter, sed solum secundum quid; quia quaelibet forma facit ens actu.	654. He says therefore first (480 225 a12) that the change from non-subject to subject takes place between contradictories and is called generation, which is the change from non-being to being. Now this can take place in two ways: one is unqualified generation, by which something comes to be in the strict sense of the word; the other is a particular kind of coming to be, i.e., in a qualified way, And he gives an example of both kinds. First of all, of the second kind, saying that when some thing is changed from non-white to white, it is not an unqualified coming to be of the whole thing, but a mere coming to be of its whiteness. Then he gives an example of the first: and he says that generation from non-being to being in the order of substance is generation in an unqualified way, in regard to which we say that a thing comes to be without qualification. And since generation is a change from non-being to being, a thing is said to be generated when it is changed from non-being to being. However, when something passes from non-white to white, it is not being changed from absolute non-being to absolute being. For, speaking strictly, what is being changed is the subject, and the subject of white is an actually existing being. Hence, since the subject remains throughout the whole change, there already was an actually existing being at the beginning of the change, although it was not a being actually existing as white. Consequently, it was not a case of unqualified coming to be but a coming to be white. But the subject of substantial form is not an actual being but a merely potential one, namely, prime matter, which at the beginning of generation is under privation and at the end under forms And so, in the case of a substance being generated, it is said that something comes to be in an unqualified sense. From this it can be concluded that when it is a case of the coming to be of a form that presupposes another form remaining in the matter, it is not unqualified generation but generation in a particular way; because each form makes a being actual.
lib. 5 l. 2 n. 7 Deinde cum dicit: quae vero ex subiecto etc., manifestat aliam partem divisionis. Et dicit quod illa mutatio quae est ex subiecto in non subiectum, vocatur corruptio. Sed quaedam est corruptio simpliciter, quae scilicet est ex esse substantiali in non esse: quaedam vero est in oppositam negationem cuiuscumque affirmationis, sicut de albo in non album, quae est corruptio huius, sicut etiam de generatione dictum est.	655. Then at (481 225 a17) he makes clear the other part of the division and states that that change which is from subject to non-subject is called “corruption”. Rut there is a corruption which is so absolutely speaking and which, namely, is from substantial being to non-being; while there is a certain corruption which is into the opposite negation of any affirmation, as from white to non-white, which is the corruption “of this”, as has already been said of generation.
lib. 5 l. 2 n. 8 Deinde cum dicit: si igitur quod non est etc., ostendit quod neutra praedictarum partium est motus. Et primo quod generatio non sit motus; secundo quod neque corruptio, ibi: neque iam corruptio et cetera. Primum probat duabus rationibus. Quarum prima talis est. Quod simpliciter non est hoc aliquid, non potest moveri; quia quod non est, non movetur: sed quod generatur simpliciter, non est hoc aliquid; est enim non ens simpliciter: ergo quod generatur simpliciter, non movetur: ergo generatio simplex non est motus. Ad manifestationem autem primae propositionis, dicit quod non ens dicitur tripliciter; et duobus modis dictum, non ens non movetur; tertio modo dictum, movetur per accidens. Uno modo dicitur ens et non ens secundum compositionem et divisionem propositionis, prout sunt idem cum vero et falso: et sic ens et non ens sunt in mente tantum, ut dicitur in VI Metaphys.; unde non competit eis motus. Alio modo dicitur non ens quod est in potentia, secundum quod esse in potentia opponitur ei quod est esse in actu simpliciter: et hoc etiam non movetur. Tertio modo dicitur non ens quod est in potentia, quae non excludit esse in actu simpliciter, sed esse actu hoc, sicut non album dicitur non ens, et non bonum: et huiusmodi non ens contingit moveri, sed per accidens, secundum quod huiusmodi non ens accidit alicui existenti in actu, cui competit moveri, sicut cum homo est non albus. Quod autem id quod simpliciter non est hoc aliquid, nullo modo moveatur, nec per se nec per accidens, patet ex hoc, quod impossibile est quod non est moveri. Unde impossibile est generationem esse motum: illud enim quod non est, fit sive generatur. Et quamvis, ut in primo huius dictum est, ex non ente fiat aliquid per accidens, ex ente autem in potentia per se; nihilominus tamen verum est dicere de eo quod fit simpliciter, quod simpliciter non est: unde moveri non potest; et eadem ratione nec quiescere. Unde generatio nec motus est, nec quies. Haec igitur inconvenientia sequuntur, si quis ponat generationem esse motum, scilicet quod non ens moveatur et quiescat.	656. Then at (482 225 a20) he shows that neither of these cases is motion. First that generation is not motion; Secondly, that corruption is not motion, at 658. He proves the first by two arguments. In the first of which he says: What is not unqualifiedly a “this something” cannot be moved, because what does not exist is not moved; but what is unqualifiedly generated is not a “this something” for it is strictly speaking a non-being. Therefore, what is unqualifiedly generated is not being moved. Hence, unqualified generation is not motion. In explanation of the first premise he says that non-being is spoken of in three senses: in the first two senses, non-being is not subject to motion, but in the third it is subject to per accidens motion. In one sense, being and non-being refer to the affirmation and negation of a predicate in a proposition, where they refer to truth and falsity; in which sense being and non-being exist only in the mind, as is said in VI Metaphysics. Hence, they are not subject to motion. In another sense, what is in potency is called non-being insofar as being in potency is the opposite of unqualified being in act. Taken in this sense no motion is possible, In a third sense, that is called “non-being” which is in potency, in such a way as to exclude not unqualified actual existence, but actually being such-and-such; for example, when non-white is called nonbeing and non-good. Such non-being is subject to motion per accidens, inasmuch as such non-being is attached to an actually existing thing subject to motion; as when a man is said to be non-white. Now, why is it that what is not unqualifiedly a “this something” is not subject to motion at all, i,e., neither per se nor per accidens? It is because it is impossible for the non-existent to be moved, Consequently, it is impossible for generation to be a motion; for generation concerns itself with what is not. And although it was said in Book I that something comes to be per accidens from non-being and per se from a being in potency, yet it is true to say of what is absolutely coming to be that, strictly speaking, it is non-being; hence, such a thing cannot be moved and, for the same reasons cannot be at rest. Hence, generation is neither motion nor rest, But if anyone insists that generation is motion, he will be forced to admit the strange proposition that non-being can be moved and can be at rest.
lib. 5 l. 2 n. 9 Secundam rationem ponit ibi: et si omne etc.: quae talis est. Omne quod movetur est in loco: sed quod non est, non est in loco, quia posset de eo dici quod alicubi esset: ergo quod non est, non movetur, et sic idem quod supra. Veritas autem primae propositionis apparet ex hoc, quod cum motus localis sit primus motuum, oportet quod omne quod movetur, moveatur secundum locum, et ita sit in loco. Remoto enim priori, removentur ea quae consequenter sunt.	657. At (483 225 a31) he gives a second reason: Whatever is moved is in a place; but what does not exist is not in a place, otherwise its place could be pointed out, Therefore, what does not exist is not moved. The truth of the first statement is evident from the fact that since local motion is the first of all motions, whatever is moved has to be moved in respect of place and, consequently, must be in a place. But if you remove the previous, you remove whatever depends upon it.
lib. 5 l. 2 n. 10 Deinde cum dicit: neque iam corruptio etc., probat quod corruptio non sit motus, quia motui nihil contrariatur nisi motus vel quies: sed corruptioni contrariatur generatio, quae neque est motus neque quies, ut ostensum est: ergo corruptio non est motus.	658. Then at (484 225 a32) he proves that ceasing-to-be is not a motion, because nothing is contrary to a motion but motion and rest, whereas the contrary of ceasing-to-be is generation, which is neither motion nor rest, as we have shown. Therefore, ceasing-to-be is not a motion.
lib. 5 l. 2 n. 11 Deinde cum dicit: quoniam autem etc., concludit ex praemissis, quod residua pars supra positae divisionis sit motus. Cum enim motus sit quaedam mutationis species, quia in eo est aliquid post aliud, quod supra dixit ad rationem mutationis pertinere; motus autem neque est generatio neque corruptio, quae sunt mutationes secundum contradictionem; relinquitur ex necessitate, cum non sint nisi tres species mutationis, quod motus sit mutatio de subiecto in subiectum. Ita tamen quod per duo subiecta, idest per duo affirmata, intelligamus contraria aut media: quia etiam privatio quodammodo est contrarium, et quandoque significatur affirmative; ut nudum, quod est privatio, et album et nigrum, quae sunt contraria.	659. Then at (485 225 a34) he concludes that the remaining member of the above-given division is motion: for since motion is a definite kind of change, because there is in it something following something (which pertains to the very idea of motion), whereas motion is neither generation nor ceasing-to-be (which are changes between contradictories), it follows of necessity, since there are only three species of change, that motion is from subject to subject. By two subjects is understood two that are affirmative, whether they be contraries or intermediates; because even privation is a kind of contrary that is expressed affirmatively, as nude, which is a privation, and as white and black, which are contraries.