A. On the Sense of the Expressions ‘To Act Initially’ and ‘To Act Instrumentally’

119. As to the question, then, since there is a difficulty about ‘to create initially or instrumentally’ [nn.17-18], one needs for this reason to know that ‘to do something initially’ can be understood in two ways: in one way by excluding every acting superior cause, so that ‘to act initially’ in this way is to act independently of an acting superior cause; in another way ‘to act initially’ can be understood to be that an inferior cause acts through its proper and intrinsic form, although it is, in acting through its form, subordinate to an acting superior cause.

120. If an instrument is distinguished from a initial cause said in the first way, then every second cause can be said to be instrumental. But if an instrument is distinguished from a initial cause in the second way then that can be said to be an instrument which does not have in itself a form active in its own order even when depending in its action on something superior, but which only acts through the motion of some other mover, as is plain of the instruments of artisans (as axe, saw, and the like). But if an instrument is posited as a principle properly active for some term, it must have some active intrinsic form: either in its ‘settled being’ before all motion of another agent, or in its ‘becoming’ when it is wholly moved by a superior agent. For if it has an active form in neither way then in no way will it properly act [cf. Ord. II d.3 n.268].

121. For since first act is the principle of second act, what has no first act in itself active in its own order has no power for a second act in that order, otherwise anything could be posited as an instrument for anything, and one could say that God created an angel through a fly as through an instrument, which is nothing. For just as it is repugnant to some nature that it be the active principle of some actions, so it is impossible for it to be, through any power at all, a principle of those actions. For although God could absolutely create cold, yet he could not create it through heat such that heat would be, in its own order, the active principle of cold (or with any other example where there would be this sort of repugnance to acting).

122. From this is plain that if an instrument is posited as effecting some effect, it must, like a second cause, have in itself before motion an active form in its settled being - or at least it receives in the actual motion an active form by which to act in its own order of acting. And this acting must be either for the initial term or for some disposition on the way to the term, so that the following proposition is in this way universally true: ‘every instrument that is properly active either acts for some disposition on the way to the initial term or it reaches the initial term through some intrinsic form, though it does so in virtue of the initial agent’ - and this whether the intrinsic form precedes the motion of the initial agent or is only present in the instrument while it is being actually moved.