1 Objection 1: It would seem that there is no order among the powers of the soul. For in those things which come under one division, there is no before and after, but all are naturally simultaneous. But the powers of the soul are contradistinguished from one another. Therefore there is no order among them.
1 Ad quartum sic proceditur. Videtur quod in potentiis animae non sit ordo. In his enim quae cadunt sub una divisione, non est prius et posterius, sed sunt naturaliter simul. Sed potentiae animae contra se invicem dividuntur. Ergo inter eas non est ordo.
2 Objection 2: Further, the powers of the soul are referred to their objects and to the soul itself. On the part of the soul, there is not order among them, because the soul is one. In like manner the objects are various and dissimilar, as color and sound. Therefore there is no order among the powers of the soul.
2 Praeterea, potentiae animae comparantur ad obiecta, et ad ipsam animam. Sed ex parte animae, inter eas non est ordo, quia anima est una. Similiter etiam nec ex parte obiectorum, cum sint diversa et penitus disparata, ut patet de colore et sono. In potentiis ergo animae non est ordo.
3 Objection 3: Further, where there is order among powers, we find that the operation of one depends on the operation of another. But the action of one power of the soul does not depend on that of another; for sight can act independently of hearing, and conversely. Therefore there is no order among the powers of the soul.
3 Praeterea, in potentiis ordinatis hoc invenitur, quod operatio unius dependet ab operatione alterius. Sed actus unius potentiae animae non dependet ab actu alterius, potest enim visus exire in actum absque auditu, et e converso. Non ergo inter potentias animae est ordo.
4 On the contrary, The Philosopher De Anima ii, 3) compares the parts or powers of the soul to figures. But figures have an order among themselves. Therefore the powers of the soul have order.
4 Sed contra est quod philosophus, in II de anima, comparat partes sive potentias animae figuris. Sed figurae habent ordinem ad invicem. Ergo et potentiae animae.
5 I answer that, Since the soul is one, and the powers are many; and since a number of things that proceed from one must proceed in a certain order; there must be some order among the powers of the soul. Accordingly we may observe a triple order among them, two of which correspond to the dependence of one power on another; while the third is taken from the order of the objects. Now the dependence of one power on another can be taken in two ways; according to the order of nature, forasmuch as perfect things are by their nature prior to imperfect things; and according to the order of generation and time; forasmuch as from being imperfect, a thing comes to be perfect.
Thus, according to the first kind of order among the powers, the intellectual powers are prior to the sensitive powers; wherefore they direct them and command them. Likewise the sensitive powers are prior in this order to the powers of the nutritive soul. In the second kind of order, it is the other way about. For the powers of the nutritive soul are prior by way of generation to the powers of the sensitive soul; for which, therefore, they prepare the body.
The same is to be said of the sensitive powers with regard to the intellectual. But in the third kind of order, certain sensitive powers are ordered among themselves, namely, sight, hearing, and smelling. For the visible naturally comes first; since it is common to higher and lower bodies. But sound is audible in the air, which is naturally prior to the mingling of elements, of which smell is the result.
5 Respondeo dicendum quod, cum anima sit una, potentiae vero plures; ordine autem quodam ab uno in multitudinem procedatur; necesse est inter potentias animae ordinem esse. Triplex autem ordo inter eas attenditur. Quorum duo considerantur secundum dependentiam unius potentiae ab altera, tertius autem accipitur secundum ordinem obiectorum. Dependentia autem unius potentiae ab altera dupliciter accipi potest, uno modo, secundum naturae ordinem, prout perfecta sunt naturaliter imperfectis priora; alio modo, secundum ordinem generationis et temporis, prout ex imperfecto ad perfectum venitur. Secundum igitur primum potentiarum ordinem, potentiae intellectivae sunt priores potentiis sensitivis, unde dirigunt eas et imperant eis. Et similiter potentiae sensitivae hoc ordine sunt priores potentiis animae nutritivae. Secundum vero ordinem secundum, e converso se habet. Nam potentiae animae nutritivae sunt priores, in via generationis, potentiis animae sensitivae, unde ad earum actiones praeparant corpus. Et similiter est de potentiis sensitivis respectu intellectivarum. Secundum autem ordinem tertium, ordinantur quaedam vires sensitivae ad invicem, scilicet visus, auditus et olfactus. Nam visibile est prius naturaliter, quia est commune superioribus et inferioribus corporibus. Sonus autem audibilis fit in aere, qui est naturaliter prior commixtione elementorum, quam consequitur odor.
6 Reply to Objection 1: The species of a given genus are to one another as before and after, like numbers and figures, if considered in their nature; although they may be said to be simultaneous, according as they receive the predication of the common genus.
6 Ad primum ergo dicendum quod alicuius generis species se habent secundum prius et posterius, sicut numeri et figurae, quantum ad esse; licet simul esse dicantur inquantum suscipiunt communis generis praedicationem.
7 Reply to Objection 2: This order among the powers of the soul is both on the part of the soul which, though it be one according to its essence, has a certain aptitude to various acts in a certain order) and on the part of the objects, and furthermore on the part of the acts, as we have said above.
7 Ad secundum dicendum quod ordo iste potentiarum animae est et ex parte animae, quae secundum ordinem quendam habet aptitudinem ad diversos actus, licet sit una secundum essentiam; et ex parte obiectorum; et etiam ex parte actuum, ut dictum est.
8 Reply to Objection 3: This argument is verified as regards those powers among which order of the third kind exists. Those powers among which the two other kinds of order exist are such that the action of one depends on another.
8 Ad tertium dicendum quod ratio illa procedit de illis potentiis in quibus attenditur ordo solum secundum tertium modum. Illae autem potentiae quae ordinantur secundum alios duos modos, ita se habent quod actus unius dependet ab altera.