II. How Practical Knowledge is Extended to Action

236. From this article [nn.228-235] the second [n.227] is plain, for this extension consists in a double aptitudinal relation, namely of conformity and of natural priority; as to priority, it is plain from what has already been adduced from the Ethics [nn.231, 233]; about conformity there is what is contained in the same place, when he says: “truth in practical consideration is conformity to correct appetite.”

237. I said ‘aptitudinal’ because neither relation is required to be actual. For the fact that an action in conformity with consideration actually follows the consideration is altogether accidental to the consideration and is contingent;Interpolation: “On the contrary: of necessity an act of intellect is prior to an act of will actually, which you set down as the first action. - True, but it does not necessarily follow thereon about the act of will actually that is action.” ⁷⁵ for if it were called action from actual extension, no action would necessarily be practical, but the same action would sometimes be practical, sometimes theoretical, which nothing is; therefore a double aptitudinal extension or aptitude for extension is enough.Interpolation: “On the contrary: in that case any knowledge would be practical, because on any knowledge there is aptitudinally apt to follow in the will the right volition conform to them which you set down as first action. - One must say that it is not true of volition of a knowable, but of volition of knowledge, and this idea is action. - On the contrary: an aptitude that agrees with one nature and is repugnant to another is not seen save through something intrinsic to it; therefore it is necessary to explain why this conformity to action agrees with this habit and is repugnant to a second. - One must say that this is from its object” [n.252]. ⁷⁶

A clarification of this is that practical knowledge is commonly conceded to be extended to action as director to directed or as regulator to regulated. But knowledge’s being naturally prior to action and conformed to it is not its being conformed to action as to something prior but its making action to be conformed to it as something posterior, or its being what action is to be conformed to, which is what it is for knowledge to direct and rule in action. But as to whether directing and conforming action to itself like this is a certain efficacy in knowledge with respect to action, see 2 Suppl. 25 q. un.

238. From this second article it is plain that the practical and speculative are not essential differences of habit or science or knowledge in general, because ‘practical’ asserts a double aptitudinal respect of knowledge, which knowledge is as it were something absolute, being toward action as toward its term, and the speculative takes away this double respect; but neither the respect nor its privation are of the essence of what is absolute, but are as it were a division of the genus through the proper features of the species, as would be the case if number were divided into odd and even and line into curved and straight. For to one of the knowledges the practical per se belongs in the second mode of per se, from the predicate’s intrinsic cause in the subject, and to the other knowledge the speculative so belongs.Text cancelled by Scotus: “A confirmation of this reason is that some practical knowledge agrees more by essential agreement with some speculative knowledge than one speculative knowledge agrees with another. - On the contrary: the distinction of knowledges by their objects is essential. - I reply: the first distinction, which is according to essential differences, is essential and from the objects as from extrinsic causes, but there can from the same differences be some posterior non-essential distinction.” ⁷⁷