Chapter 100 — That what God does beside the order of nature is not contrary to nature

It would seem, however, necessary to observe that although God sometimes does something beside the order assigned to things, he does nothing contrary to nature.

For, since God is pure act, but all other things have some admixture of potency, it follows that God must be compared to all things as the mover to the thing moved, and as the active to the potential. Now, when that which in the natural order is in potency with regard to a certain agent is acted upon by that agent, this is not contrary to nature simply, although sometimes it is contrary to that particular form which is corrupted by such action. Thus when fire is generated, and air is corrupted through the action of the fire, both generation and corruption are natural. Consequently, whatever is done by God in created things is not contrary to nature, although it may seem to be contrary to the order proper to a particular nature.

Again. Since God is the first agent, as we have proved, (Bk. 1, ch. 13.) all subsequent agents are likened to his instruments. Now, the purpose of an instrument is to serve the action of the principal agent while it is being moved by it: hence the matter and form of an instrument must be such as to be suitable for the action intended by the principal agent. Hence it is not contrary but most becoming to the nature of an instrument to be moved by the principal agent. Neither, therefore, is it contrary to nature that creatures be moved by God in any way whatsoever, since they were made that they might serve him.

Further. Even in corporeal agents we observe that the movements resulting in inferior bodies from the influence of higher bodies are neither violent nor unnatural, although they may seem unbecoming to the natural movement which the inferior body has as being proper to its form. For we do not say that the ebb and flow of the sea is a violent movement, since it results from the influence of a heavenly body, although the natural movement of water is only in one direction (namely, to the center). Much less, therefore, can whatsoever God does in any creature be described as violent or unnatural.

Besides. The first measure of every essence and nature is God as the first being, who is the cause of being in all other things. Since, then, we judge of everything by its measure, we must regard as natural to a thing that whereby it is conformed to its measure. Hence whatever is implanted in a thing by God is natural to that thing. Therefore, if something else be implanted by God in that same thing, it will not be unnatural.

Moreover. All creatures are compared to God as works of art are compared to the artist, as appears from what we have already said. (Bk. 2, ch. 24.) Hence all nature is the work of the divine art. Now it is not inconsistent with a work of art that the artist make some alteration in his work, even after giving it its first form. Neither, therefore, is it contrary to nature if God does something in natural things other than that which occurs in the ordinary course of nature.

Thus Augustine says: God, the creator and author of all natures, does nothing unnatural, because that is natural to each thing which is caused by him from whom is all measure, number and order in nature. (Augustine, Contra Faustum, bk. 16, ch. 3.)