Chapter 19 — That God is of infinite power

From this it is also apparent that God is infinite in power. For power is consequent upon a thing’s essence; for anything whatever is able to act according to the manner in which it exists. Therefore, if God is infinite in his essence, his power must be infinite.

This is also clear if we diligently consider the order of things. For any given thing has a receptive or passive power according as it is in potency, but it has an active power according as it is in act. Hence what is exclusively in potency (namely, prime matter) has an unlimited power of receptivity, but has no part in active power. And in the scale of being above matter, the more a thing has of form, the more it abounds in the power of acting. This is why fire is the most active of all the elements. Therefore, God, who is pure act without any admixture of potency, infinitely abounds in active power above all others.