Authors/Thomas Aquinas/metaphysics/liber9/lect4

Lecture 4

Latin	English
lib. 9 l. 4 n. 1 Postquam philosophus exclusit falsas opiniones circa potentiam et actum, hic determinat veritatem; et circa hoc duo facit. Primo ostendit quomodo actus praecedat potentiam in subiecto. Secundo quomodo potentia praecedens actum, ad actum reducatur, ibi, quoniam autem possibile. Dicit ergo primo, quod cum potentiarum quaedam sint inditae his quorum sunt, sicut sensus animalibus; quaedam vero per consuetudinem acquirantur, sicut ars tibicinandi et aliae huiusmodi artes operativae; quaedam vero acquirantur per doctrinam sive disciplinam, sicut medicina et aliae huiusmodi artes: dictarum potentiarum quaecumque per consuetudinem et rationem nobis insunt, necesse est primum agere et praeexercitari in eorum actibus antequam acquirantur; sicut tibicinando, aliquis fit tibicinator; et considerando medicinalia, aliquis fit medicus. Sed aliae potentiae, quae non acquiruntur per consuetudinem, sed insunt a natura et sunt in patiendo, sicut patet de potentiis sensitivis, non procedunt a suis actibus. Non enim aliquis videndo acquirit sensum visus; sed ex eo quod potentiam visivam habet, fit actu videns.	1815. Having rejected the false opinions about potency and actuality the Philosopher now establishes the truth about them; and in regard to this he does two things. First, he shows how actuality is prior to potency in the same subject; and second (1816), how potency, when it is prior to actuality, is brought to a state of actuality. He accordingly says, first, that, since (1) some potencies are innate in the things of which they are the potencies, as the sensory powers in animals; and (2) some are acquired by practice, as the art of flute-playing and other operative arts of this kind; and some are acquired by teaching and learning, as medicine and other similar arts; all of the abovementioned potencies which we have as a result of practice and the use of reason must first be exercised and their acts repeated before they are acquired. For example, one becomes a harpist by playing the harp, and one becomes a physician by studying medical matters. But (1) other potencies which are not acquired by practice but which belong to us by nature and are passive, as is evident in the case of sensory powers, are not a result of exercise; for one does not acquire the sense of sight by seeing but actually sees because he has the power of sight.
lib. 9 l. 4 n. 2 Deinde cum dicit quoniam autem ostendit quomodo potentiae praecedentes actum reducuntur ad actum; et circa hoc duo facit. Primo enim ostendit quomodo in hoc differunt diversae potentiae adinvicem, scilicet rationales et irrationales. Secundo ostendit qualiter rationales potentiae ad actum reducantur, ibi, necesse ergo. Circa primum tria facit. Primo praemittit quaedam necessaria ad praedictam differentiam considerandam: quorum unum est, quod in ratione possibilis oportet multa considerare. Non enim dicitur possibile respectu cuiusque, sed respectu alicuius determinati. Unde oportet possibile, esse aliquid possibile, utputa ambulare vel sedere. Et similiter quod potest aliquid facere vel pati, non potest illud quocumque tempore facere aut pati; sicut arbor non potest fructificare nisi determinato tempore. Et ideo cum dicitur aliquid esse possibile, oportet determinare quando sit possibile. Et similiter oportet determinare quomodo sit possibile. Non enim possibile, quocumque modo potest agere aliquid vel pati; sicut aliquis sic potest ambulare, scilicet tarde, non autem velociter. Et simile est de aliis circumstantiis quae consueverunt determinari in definitionibus rerum; sicut quo instrumento, quo loco, et alia huiusmodi.	1816. Now that which (762). Here he shows how those potencies which are prior to actuality are brought to actuality; and in regard to this he does two things. First, he shows how different potencies—rational and irrational potencies—differ from each other in this respect. Second (1820), he shows how rational potencies are brought to a state of actuality (“Therefore, there must”). In regard to the first he does three things. First, he lays down certain conditions required for the study of the aforesaid differences, and (1) one of these is that it is necessary to consider several qualifications in the definition of the capable or potential. For the capable does not refer to just anything at all but to something definite. Hence the capable must be capable of something, such as to walk or to sit. And similarly what can act or be acted upon cannot act or be acted upon at any time whatever; for example, a tree can bear fruit only at some definite time. Therefore, when it is said that something is capable, it is necessary to determine when it is capable. And it is also necessary to determine in what way it is capable, for that which is capable can neither act nor be acted upon in every way; for example, one can walk in this way, namely, slowly, but not rapidly. And the same thing is true of the other qualifications which they are accustomed to give in the definitions of things, for example, by what instrument, in what place, and the like.
lib. 9 l. 4 n. 3 Aliud quod praetermittit est, quod quaedam sunt possibilia secundum rationem, et potentiae horum possibilium sunt rationales. Quaedam vero possibilia sunt irrationalia, et potentiae irrationales. Et quidem potentiae rationales non possunt esse nisi in rebus animatis; sed potentiae irrationales possunt esse in ambobus, scilicet in rebus animatis et inanimatis. Et non solum in plantis et brutis animalibus, quae ratione carent, sed etiam in ipsis hominibus, in quibus inveniuntur quaedam principia actionum et passionum quae sunt sine ratione, ut potentia nutritiva et augmentativa, et gravitas, et alia huiusmodi.	1817. Another qualification which he lays down is that (a) some things are capable of something because of a rational plan, and the potencies for these capabilities are rational. (b) But some capabilities are irrational, and the potencies for these are irrational. Again, rational potencies can exist only in living things, whereas irrational potencies can exist in both, i.e., in both living and nonliving things. And they exist not only in plants and in brute animals, which lack reason, but also in men themselves, in whom are found certain principles both of acting and of being acted upon which are irrational; for example, the powers of nutrition and growth, and weight, and other accidents of this kind.
lib. 9 l. 4 n. 4 Secundo ibi, tales quidem ponit differentiam praedictarum potentiarum; dicens, quod in potentiis irrationabilibus necesse est, quando passivum appropinquat activo, in illa dispositione qua passivum potest pati et activum potest agere, necesse est quod unum patiatur et alterum agat; ut patet quando combustibile applicatur igni. In potentiis vero rationalibus, non est necessarium: non enim necesse est aedificatorem aedificare quantumcumque sibi materia appropinquaret.	1818. And since (763). (2) Second, he gives the difference between the potencies in question. He says that in the case of irrational potencies when the thing capable of being acted upon comes close to the thing which is capable of acting, then in accordance with that disposition whereby that able to be acted upon can be acted upon and that capable of acting can act, it is (+) necessary that the one be acted upon and that the other act. This is clear, for instance, when something combustible comes in contact with fire. But in the case of rational potencies this is not necessary; for no matter how close some material may be brought to a builder, it is not (~) necessary that he build something.
lib. 9 l. 4 n. 5 Tertio ibi, hae quidem assignat causam praedictae differentiae; dicens, quod potentiae irrationales ita se habent, quod una est factiva tantum unius; et ideo praesente passivo necesse est quod faciat illud unum cuius est factiva. Sed una et eadem potentia rationalis est factiva contrariorum, ut superius habitum est. Si igitur necessarium esset, quod praesente passivo faceret illud cuius est factiva, sequeretur quod simul faceret contraria; quod est impossibile. Sicut si medicus induceret sanitatem et aegritudinem.	1819. For the latter (764). (3) Third, he gives the reason for the difference pointed out. (a) He says that irrational potencies are such that each is productive of only one effect, and, therefore, when such a potency is brought close to something that is capable of being acted upon, it must produce the one effect which it is capable of producing. (b) But one and the same rational potency is capable of producing contrary effects, as was said above (1789-93). Therefore, if, when it is brought close to something capable of being acted upon, it would be necessary for it to bring about the effect which it is capable of producing, it would follow that it would produce contrary effects at the same time; but this is impossible. For example, it would follow that a physician would induce both health and sickness.
lib. 9 l. 4 n. 6 Deinde cum dicit necesse ergo ostendit quid requiratur ad hoc quod potentiae rationales exeant in actum, ex quo non sufficit propinquitas passi. Et circa hoc tria facit. Primo ostendit per quid potentia rationalis reducatur in actum: concludens ex dictis, quod cum potentia rationalis se habeat communiter ad duo contraria, et ita cum a causa communi non procedat effectus determinatus, nisi sit aliquid proprium quod causam communem ad hunc effectum magis determinet quam ad illum, sequitur quod necesse est, praeter potentiam rationalem, quae est communis ad duo contraria, poni aliquid, quod appropriet eam ad alterum faciendum ad hoc quod exeat in actum. Hoc autem est appetitus aut prohaeresis, idest electio quorumcumque, idest electio quae pertinet ad rationem. Quod enim aliquis considerat, hoc facit; ita tamen si existit in dispositione, qua est potens agere, et passivum adsit. Unde sicut potens potentia irrationali necessario agit, passivo appropinquante; ita omne potens secundum rationem, necesse est quod faciat quando desiderat illud cuius habet potentiam, et eo modo quo habet. Habet autem potentiam faciendi cum passivum praesens fuerit, et ita se habeat quod possit pati; aliter facere non posset.	1820. Therefore there must (765). He then shows what is necessary in order for rational potencies to begin to act, seeing that closeness to the thing capable of being acted upon is not sufficient. In regard to this he does three things. First, he reveals the principle by which a rational potency is made to act. He concludes from the above discussions that since a rational potency has a common relationship to two contrary effects, and since a definite effect proceeds from a common cause only if there is some proper principle which determines that common cause to produce one effect rather than the other, it follows that it is necessary to posit, in addition to the rational power which is common to two contrary effects, something else which particularizes it to one of them in order that it may proceed to act. And this “is appetite or choice,” i.e., the choosing of one of the two, or the choice which involves reason; for it is what a man intends that he does, although this occurs only if he is in that state in which he is capable of acting and the patient is present. Hence, just as an irrational potency which is capable of acting must act when its passive object comes close to it, in a similar fashion every rational potency must act (a) when it desires the object of which it has the potency, and (b) in the way in which it has it. And it has the power of acting when the patient is present and is so disposed that it can be acted upon; otherwise it could not act.
lib. 9 l. 4 n. 7 Secundo ibi, nullo namque respondet tacitae quaestioni. Posset enim aliquis quaerere, quare, cum dixerit quod omne potens secundum rationem quando desiderat, necessario agit passivo praesente, non addit, si nihil prohibet exterius. Sed ipse respondet, quod illud, scilicet nullo exteriorum prohibente, non oportet addere. Dictum est enim quod necesse est agere si habeat potentiam, quae est sufficiens ad faciendum. Sed hoc non est quolibet modo; sed quando illud quod habet potentiam, aliquo modo se habet: et in hoc excluduntur ea quae exterius prohibent. Nam ea quae exterius prohibent, removent aliqua eorum quae posita sunt superius in determinatione communi possibilis; ut scilicet vel non sit possibile tunc, vel non possibile hoc modo, vel aliquid huiusmodi.	1821. For it is unnecessary (766). Second, he answers an implied question. For since he had said that everything capable of acting as a result of a rational plan, when it desires something of which it is the potency, acts of necessity on the patient before it, someone could ask why he did not add this qualification, namely, “when nothing external hinders it”; for it has been said that it must act if it has sufficient power to act. But this does not occur in any and every way, but only when the thing having the potency is disposed in some particular way; and in this statement external obstacles are excluded. For the things which hinder it externally remove some of it desires, and assuming that some the qualifications laid down in the common definition of the capable or possible, so that it is not capable at this time or in this way or the like.
lib. 9 l. 4 n. 8 Tertio ibi, propter quod docet evitare inconveniens, quod primo sequebatur, scilicet quod potentia rationalis simul faceret contraria. Non enim sequitur quod, si necesse est quod faciat potentia rationalis quod desiderat, et dato quod aliqui simul velint secundum rationem, aut cupiant secundum appetitum sensitivum, facere duo diversa aut contraria, quod propter hoc faciant. Non enim sic habent potentiam contrariorum, quod simul contraria faciant; sed sic faciunt, sicut habent potentiam, ut dictum est.	1822. And for this (767). Third, he instructs us to avoid the absurd conclusions which he first said would follow, namely, that a rational potency would produce contrary effects at the same time. For if it is necessary that a rational potency should do what it should wish either by reason or by sense appetite, and granted that it should wish to do two different or contrary things at the same time, it does not follow for this reason that they will do them. For they do not have power over contrary effects in such a way that they may do contrary things at the same time; but they act according to the way in which they have a potency, as has been explained (1816-20).