C. Objections and their Solution

35. Against the third of these members [n.32] there is a twofold objection:

First as follows: whatever God does immediately in respect of some creature he does in an instant, because (Physics 8.10.266b4-5) an infinite power acts in an instant, for a finite and an infinite power cannot act with equal measure; therefore God cannot, after the instant of guilt, justify the soul through grace in the immediate time.

36. Further, was the justification a motion or was it an alteration? Not an alteration because it would not happen in an instant. Not motion because there would be no succession according to parts of the movable thing, namely of the soul, because the soul is indivisible; nor according to parts of the form, namely of grace; nor according to means between extremes, for there is no mean between privative opposites in respect of a naturally fit subject, just as there is absolutely none between contradictories; nor is one of these opposites acquired or lost part by part; nor is the subject divisible.

37. To the first objection [n.35] I say that if God voluntarily, and not necessarily, acts in an instant of some time, he must wait for the ‘then’ so that he may act in a determinate instant of the time; but he can act in a time in whose first instant he did not act; it is therefore true that God can do in an instant what he does immediately, but it is not necessary for him to act in an instant.

38. To the second [n.36] I say that, when speaking strictly about motion and alteration in the way the Philosopher does [cf. d.2 n.117 supra], passive justification is neither motion nor alteration but has something of both: from alteration it has that it is in a subject as a simple and indivisible form; from time and motion it has that it is in no indivisible measure but is in time, and in this respect it fails of being alteration. But it fails of being motion because it is not a flow according to the parts of the form and of the movable thing, or according to means between extremes, for here there are no means, as was proved [n.36].

39. Here is an example of this: a movable thing passes from the form under which it was in the ultimate instant of rest in such a way that, after that instant, there is a continuous losing of the form according to its parts and a continuous acquiring of the opposite form. If the opposite form were present in the whole time then, since its parts would not be acquired successively, it would be like the issue at hand, because then the acquiring of the form would be neither motion nor alteration, just as the passage now from alteration to motion is neither alteration nor motion.

40. But why is an undergoing caused by a natural agent an alteration or a motion but this is not?

I reply that if a natural agent can introduce a form suddenly, it introduces it through alteration; and if it cannot, it must act in time and so through motion and so by moving. But God, although he can introduce a form in an instant, yet - if he were not to introduce it in an instant - he can introduce the whole of it in time such that he does not introduce it part after part; for being able to act in time is not a mark of imperfection in an agent, although the necessity of acting in time is an imperfection.