Summa summae S. Thomae, Tomus II

D. Thomas, q. 10.

I say 1°: The will is moved naturally and necessarily, by a necessity of specification, to the good in common, because it is its object¹. But the power naturally tends to its object, so that it cannot tend to the opposite; likewise to the ultimate end, or beatitude, as apprehended under its common notion; because the ultimate end stands to things desirable just as first principles stand to things speculative. But the intellect knows first principles naturally. Therefore the will wills the ultimate end naturally. Add that on the part of the opposite of the good in common and of beatitude in common no reason of good can be apprehended.

I say 2°: The will can be moved by necessity with respect to specification by no particular good; because there is none which under any consideration, whether by reason of itself or by reason of something annexed to it, cannot be apprehended as not good, or as deficient from some good, since none is so perfect that nothing is wanting to it². Nor with respect to exercise; because anyone, whatever particular good it be, can not think of it, and consequently not will it³.

I say 3°: The will is not moved by God of necessity, neither with respect to exercise nor with respect to specification, except in those things to which it is moved naturally⁴

It is proved.⁵ It does not belong to the divine providence, as Dionysius says, c. 4 of the De Divin. nomin., to corrupt the nature of things, but to preserve it. Hence he moves all things according to their condition, so that from necessary causes necessary effects follow through the divine motion, but from contingent causes contingent effects follow. Since therefore the will is an active principle not determined to one thing, but standing indifferently toward many things, God moves it in such a way that he does not determine it of necessity to one thing, but its motion remains contingent and not necessary, except in those things to which it is moved naturally.

You will object 1°: Every agent that cannot be resisted moves of necessity. And who resists God's motion upon his will? Therefore.

I answer.⁶ The divine will extends not only that something be done through the thing it moves, but also that it be done in that manner which suits its nature. And therefore it would repugn the divine motion more if the will were moved of necessity, which does not suit its nature, than if it were moved freely, as suits its nature.