Authors/Thomas Aquinas/metaphysics/liber9/lect2

Lecture 2

Latin	English
lib. 9 l. 2 n. 1 Postquam philosophus ostendit quot modis dicitur potentia, hic determinat de potentia per comparationem ad ea quibus inest; et dividitur in duas partes. In prima ostendit differentiam potentiarum adinvicem secundum diversitatem eorum in quibus sunt. In secunda ostendit quomodo potentia et actus sint simul vel non sint in substantia, ibi, sunt autem quidam. Circa primum tria facit. Primo ostendit differentiam potentiarum secundum ea in quibus sunt; dicens, quod cum potentiae sint principia quaedam agendi et patiendi, horum principiorum quaedam sunt in inanimatis, et quaedam in animatis. Et, quia animata componuntur ex corpore et anima, principium autem agendi et patiendi, quae sunt in corpore animatorum, non differunt ab his quae sunt in animatis, ideo addit, et in anima. Quia videlicet principia agendi quae sunt in anima, manifeste differunt ab his quae sunt in rebus inanimatis.	1786. Having explained the different senses in which the term potency is used, here the Philosopher establishes the truth about potency in relation to the things in which it is found. This is divided into two parts. In the first (1786) he shows how these potencies differ from each other on the basis of a difference in their subjects. In the second (1795) he shows how potency and actuality are simultaneous or not in a substance. In regard to the first he does three things. First, he shows how potencies differ on the basis of a difference in their subjects. He says that, since potencies are principles both for acting and being acted upon, some of these principles are in non-living things and some in living ones. And since living things are composed of body and soul, and the principles for acting and being acted upon which are present in the body of living things do not differ from those in non-living ones, he therefore adds “and in the soul,” because the principles of action which are present in the soul clearly differ from those present in non-living things.
lib. 9 l. 2 n. 2 Et iterum animae plures sunt: quarum multae non multum differunt in agendo et patiendo a rebus inanimatis, quae instinctu naturae operantur. Nam partes animae nutritivae et sensitivae, impulsu naturae operantur. Sola autem pars animae rationalis est domina sui actus: in quo differt a rebus inanimatis. Et ideo postquam dixit differentiam in anima, addit, et in anima rationem habente. Quia scilicet illa principia animatorum a principiis inanimatorum specialiter differunt, quae sunt in parte animae rationalis. Unde patet quod potentiarum animae, aliae sunt irrationales, aliae vero cum ratione.	1787. Again, there are several kinds of souls, and many of these do not differ to any great extent both in acting and in being acted upon from non-living things which act by natural instinct; for the parts of the nutritive and sentient soul act by natural impulse. Now only the rational part of the soul has dominion over its acts, and it is in this respect that it differs from non-living things. Therefore, having pointed out the difference between souls, he adds “and in the soul having reason,” because those principles of living things which are found in the rational part of the soul differ specifically from those of non-living things. Hence it is evident that some powers of the soul are irrational and others rational.
lib. 9 l. 2 n. 3 Et quae sunt cum ratione exponit, cum subdit, quod omnes artes factivae, ut fabrilis et aedificativa et ceterae huiusmodi, quarum actiones in materiam exteriorem transeunt, et omnes scientiae, quae scilicet non habent operationem in exteriorem materiam transeuntem, sicut sunt scientiae morales et logicae, omnes inquam huiusmodi artes, potentiae quaedam sunt. Quod exinde concluditur, quia sunt principia permutationis in aliud inquantum aliud est; quod est definitio potentiae activae, ut ex praedictis patet.	1788. He explains what he means by those which are rational, when he adds that (1) “all the productive arts,” as the building and constructive arts and the like, whose actions pass over into (+) external matter, and (2) all sciences which do not perform actions that pass over into (~) external matter, as the moral and logical sciences—all arts of this kind, I say, are powers. And this is concluded from the fact that they are principles of change in some other thing inasmuch as it is other. This is the definition of active power, as is clear from what was said above.
lib. 9 l. 2 n. 4 Secundo ibi, et quae quidem assignat differentiam inter praedictas potentias; dicens, quod potentiae rationales eaedem se habent ad contraria; sicut ars medica quae est quaedam potentia, ut dictum est, se habet ad infirmitatem et sanitatem faciendam. Potentiae autem irrationales non se habent ad opposita, sed una est ad unum effectum tantum, per se loquendo. Sicut calidum solis calefacit per se, etsi per accidens possit esse causa frigiditatis, inquantum aperiendo poros exhalare facit interius calidum; vel consumendo materiam humoris calidi, ipsum calidum destruit, et per consequens infrigidat.	1789. And all those (747). Second, he gives the difference between the above-mentioned potencies. He says that the same rational potencies are (+) open to contrary determinations as the art of medicine, which is a potency, as has been explained (1404-7), can produce both health and sickness. But irrational potencies are not (~) open to contrary determinations, but properly speaking each is determined to one thing; for example, the heat of the sun has as its proper effect to heat, although it can be the cause of coldness inasmuch as by opening the pores it causes the loss of internal heat; or by absorbing the matter of a hot humor it destroys the heat and thereby cools.
lib. 9 l. 2 n. 5 Deinde cum dicit causa autem assignat philosophus causam praedictae differentiae; quae talis est. Nam scientia, quae est potentia rationalis, est quaedam ratio rei scitae in anima. Eadem autem ratio rem manifestat et eius privationem, licet non similiter; quia primo manifestat eam rem existentem, per posterius autem eius privationem. Sicut per rationem visus per se cognoscitur ipsa visiva potentia, ex consequenti vero caecitas; quae nihil aliud est, quam ipsa carentia visus in eo quod natum est habere visum. Unde necessarium est, si scientia est quaedam ratio rei scitae in anima, quod eadem sit scientia contrariorum. Unius quidem per prius et secundum se, alterius vero per posterius. Sicut medicina per prius est cognoscitiva et factiva sanitatis, per posterius autem infirmitatis; quia et hoc, ut iam dictum est, est de ratione rei scitae in anima, quae est unius oppositorum secundum se, et alterius secundum accidens.	1790. And the reason (748). Then the Philosopher gives the reason for the aforesaid difference, and it is as follows: a science, which is a rational potency, is a conception of the thing known existing in the mind. Now the same conception explains both the thing and its privation, although not in the same way, because it first makes known the existing thing and subsequently its privation; for example, the power of sight itself is known properly by means of the notion of sight, and then blindness is known, which is nothing but the very lack of sight in a thing naturally disposed to have it. Hence, if science is a conception of the thing known existing in the mind, the same science must deal with contraries—with one primarily and properly, and with the other secondarily; for example, the art of medicine is cognitive and productive primarily of health and secondarily of sickness, because, as has been pointed out, this art has to do with the conception of the thing known in the mind, and this conception is of one of the contraries directly and of the other indirectly.
lib. 9 l. 2 n. 6 Et, quia quod philosophus supra de privatione dixerat, postmodum ad contrarium transtulit, ostendit quod eadem ratio est de contrario et privatione. Sicut enim per negationem et ablationem manifestatur privatio, ut puta ablatio visus manifestat caecitatem; ita per negationem et ablationem manifestatur contrarium: quia privatio, quae nihil aliud est quam ablatio alterius, est quoddam primum principium inter contraria. Omnium enim contrariorum unum est sicut perfectum, alterum vero sicut imperfectum, et privatio alterius. Nigrum enim est privatio albi, et frigidum est privatio calidi. Sic igitur patet, quod eadem scientia se habet ad contraria.	1791. And since the remarks which the Philosopher had made above about privation he afterwards transferred to contraries, he shows that the same conception applies to a contrary and to a privation; for just as a privation is explained by negation and removal (for example, the removal of sight explains blindness), in a similar fashion a contrary is explained by negation and removal; because privation, which is merely the removal of some attribute, is a sort of first principle among contraries. For in the case of all contraries one stands as something perfect and the other as something imperfect and the privation of the former; black, for example, is the privation of white, and cold is the privation of heat. Thus it is evident that the same science extends to contraries.
lib. 9 l. 2 n. 7 Hoc autem manifestat consequenter, cum dicit quoniam autem accedit ergo ad assignandum causam praedictae differentiae. Manifestum est enim quod res naturales operantur per formas sibi inhaerentes. Non autem possunt eidem inesse formae contrariae. Unde impossibile est quod eadem res naturalis faciat contraria. Sed scientia est quaedam potentia actionis, et motus principium, ex eo quod aliquis habet rationem rei faciendae, et hoc principium motus est in anima. Et quia ita est, sequitur quod res naturales faciant unum tantum; sicut salubre facit solum sanitatem, et calefactivum facit solum caliditatem, et infrigidativum facit solum frigiditatem. Sed ille qui agit per scientiam operatur utrumque oppositorum, quia eadem ratio est utriusque in anima, quia habet principium talis motus, licet non similiter, sicut dictum est.	1792. Moreover, since (749). He next develops this point, and he begins to give the reason for the aforesaid difference. For it is clear that natural things act by reason of the forms present in them. But contrary forms cannot exist in the same subject. Therefore it is impossible for the same natural thing to produce contrary effects. But science is a potency for acting and a principle of motion, because a person has an idea of the thing to be made and this principle of motion is in the mind. And since this is so it follows that natural things produce only one effect; for example, what is healthful produces only health, and what is capable of heating produces only heat, and what is capable of cooling produces only cold. But one who acts by science may be occupied with both contraries, because the conception of both contained in the soul is the same; for the soul possesses the principle of such motion, although not in the same way, as has been explained.
lib. 9 l. 2 n. 8 Et ideo, sicut actio naturalis procedit ad effectum, quasi copulata ad formam, quae est principium actionis cuius similitudo relinquitur in effectu, ita anima movet per suam operationem ad ambo opposita ab eodem principio, idest a ratione quae est una duorum oppositorum, copulans ad ipsum principium utrumque motum, et ad ipsum principium utrumque terminans, inquantum similitudo illius principii in utroque oppositorum in esse productorum salvatur. Manifestum est igitur quod potentiae rationales contrarium faciunt potentiis irrationalibus; quia potentia rationalis facit opposita, non autem potentia irrationalis, sed unum tantum. Et hoc ideo est, quia unum principium oppositorum continetur in ratione scientiali, ut dictum est.	1793. Therefore, just as a natural activity proceeds to bring about its effect as though it were united to its form, which is the principle of action whose likeness remains in the effect, in a similar fashion the soul by its activity proceeds to bring about both opposites “by the same principle,” i.e., by the conception which is one for the two opposites, uniting both motions to this principle and causing both to terminate in it inasmuch as the likeness of this principle is verified in both of the opposites brought into being. Therefore it is evident that rational powers produce an effect opposite to irrational powers, because a rational power produces contrary effects, whereas an irrational power produces only one effect. The reason is that a single principle of contrary effects is contained in the conception belonging to a science, as has been explained.
lib. 9 l. 2 n. 9 Deinde cum dicit palam autem ponit comparationem quorumdam modorum potentiae superius sub eis positorum. Dictum est supra quod aliquid dicitur habere potentiam activam vel passivam, quandoque quidem ex hoc solum quod potest agere vel pati, quandoque vero ex hoc quod potest bene agere vel pati. Dicit ergo quod ad potentiam bene faciendi vel patiendi sequitur potentia faciendi, sed non e converso. Sequitur enim, si aliquis benefacit, quod faciat, sed non e converso.	1794. It is also evident (750). He explains the relationship of some of the senses of potency mentioned above to those which come under them. For it was stated above that a thing is said to have active or passive potency, sometimes only because it can act or be acted upon, and sometimes because it can act or be acted upon well. Therefore he says that the potency for acting or being acted upon well involves the potency for acting or being acted upon, but not the reverse. For it follows that someone acts if he acts well, but the opposite of this is not true.