Chapter 22 — That God can do all things

Hence it is clear that the divine power is not determined to one particular effect.

For if it belongs to God alone to create, it follows that whatever things cannot be produced by their cause save by way of creation must be immediately produced by him. Now such are all separate substances (which are not composed of matter and form, and the existence of which we will suppose for the present), (See below, ch. 46.) and likewise all corporeal matter. These things then, being distinct from one another, are the immediate effect of the aforesaid power. Now no power that produces immediately a number of effects not from matter is determined to one effect. I say “immediately,” because if it produced them through intermediaries, the diversity might be owing to the intermediary causes. And I say “not from matter,” because the same agent by the same action causes different effects according to the diversity of matter; thus the heat of fire hardens clay and melts wax. Therefore, God’s power is not determined to one effect.

Again. Every perfect power extends to all those things to which its essential and proper effect can extend: thus the art of building, if perfect, extends to whatever can have the nature of a house. Now God’s power is the essential cause of being, and being is its proper effect, as stated above. (Ch. 21.) Therefore, it extends to all that is not incompatible with the notion of being: for if his power were confined to one effect alone, it would be the cause of a being, not as such, but as this particular being. Now the opposite of being, which is non-being, is incompatible with the notion of being. Therefore, God can do all things but those which include the notion of non-being, and such are those that imply a contradiction. It follows, therefore, that God can do whatever does not imply a contradiction.

Again. Every agent acts insofar as it is actual. Therefore, the mode of an agent’s power in acting follows its mode of act: for man begets man, and fire begets fire. Now God is perfect act, possessing in himself the perfections of all things, as was proved above. (Bk. 1, ch. 28.) Therefore, his active power is perfect, and extends to all things whatsoever that are not incompatible with the notion of act. But these are only those which imply a contradiction. Therefore, God can do everything except these things.

Moreover. To every passive potency there corresponds an active potency, since potency is for the sake of act, as matter for the sake of form. Now a being in potency cannot come to be in act save by the power of something in act. Thus potency would be without purpose were there no active power of an agent that could reduce it to act, and yet nothing in the things of nature is void of purpose. Thus we find that all things that are in the potency of matter in things subject to generation and corruption can be reduced to act by the active power which is in the heavenly body, which is the first active force in nature. Now just as the heavenly body is the first agent in regard to lower bodies, so God is the first agent in respect of all created being. Therefore, God can do everything is in the potency of created being by his active power. And all that is not incompatible with created being is in the potency of created being, just as whatever does not destroy human nature is in the potency of human nature. Therefore, God can do all things.

Further. That some particular effect is not subject to the power of some particular agent may be due to three things. First, because it has no affinity or likeness to the agent: for every agent produces its like in some way. Hence the power in human seed cannot produce a brute animal or a plant, and yet it can produce a man who surpasses the things mentioned. Second, on account of the excellence of the effect, which surpasses the capacity of the active power: thus the active power of a body cannot produce a separate substance. Third, because the effect requires a particular matter on which the agent cannot act: thus a carpenter cannot make a saw, because his art does not enable him to act on iron, of which a saw is made.

Now in none of these ways can any effect be withheld from the divine power. For nothing can be impossible to him on account of unlikeness in the effect, for everything is like him insofar as it has being, as we have proved above. (Cc. 6, 15.) Nor again on account of the excellence of the effect, since it has been proved (Bk. 1, cc. 28, 41.) that God is above all beings in goodness and perfection. Nor again on account of a defect in matter, since he is the cause of matter, which cannot be caused except by creation. Moreover, he needs no matter in acting, since he brings a thing into being without anything preexistent. (Ch. 16.) Therefore, lack of matter cannot hinder his action from producing its effect.

It remains, therefore, that God’s power is not confined to any particular effect, but is able to do simply all things: and this means that he is almighty.

Hence also divine Scripture teaches this as a matter of faith. For it is said in the person of God: I am God Almighty; walk before me, and be perfect (Gen 17:1); and: I know that you can do all things (Job 42:2); and in the person of the angel: with God no word will be impossible (Luke 1:37).

By this is refuted the error of certain philosophers who asserted that only one effect was immediately produced by God, as though his power were confined to the production of it; and that God can only act according to the course of natural things. Of these it is said: who looked upon the Almighty as if he could do nothing (Job 22:17).