FIRST ARTICLE [I, Q. 25, Art. 1]
Whether There Is Power in God?
Objection 1: It seems that power is not in God. For as primary matter is to power, so God, who is the first agent, is to act. But primary matter, considered in itself, is devoid of all act. Therefore, the first agent—namely, God—is devoid of power.
Obj. 2: Further, according to the Philosopher (Metaph. vi, 19), better than every power is its act. For form is better than matter; and action than active power, since it is its end. But nothing is better than what is in God; because whatsoever is in God, is God, as was shown above (Q. 3, A. 3). Therefore, there is no power in God.
Obj. 3: Further, Power is the principle of operation. But the divine power is God's essence, since there is nothing accidental in God: and of the essence of God there is no principle. Therefore there is no power in God.
Obj. 4: Further, it was shown above (Q. 14, A. 8; Q. 19, A. 4) that God's knowledge and will are the cause of things. But the cause and principle of a thing are identical. We ought not, therefore, to assign power to God; but only knowledge and will.
On the contrary, It is said: "Thou art mighty, O Lord, and Thy truth is round about Thee" (Ps. 88:9).
I answer that, Power is twofold—namely, passive, which exists not at all in God; and active, which we must assign to Him in the highest degree. For it is manifest that everything, according as it is in act and is perfect, is the active principle of something: whereas everything is passive according as it is deficient and imperfect. Now it was shown above (Q. 3, A. 2; Q. 4, AA. 1, 2), that God is pure act, simply and in all ways perfect, nor in Him does any imperfection find place. Whence it most fittingly belongs to Him to be an active principle, and in no way whatsoever to be passive. On the other hand, the notion of active principle is consistent with active power. For active power is the principle of acting upon something else; whereas passive power is the principle of being acted upon by something else, as the Philosopher says (Metaph. v, 17). It remains, therefore, that in God there is active power in the highest degree.
Reply Obj. 1: Active power is not contrary to act, but is founded upon it, for everything acts according as it is actual: but passive power is contrary to act; for a thing is passive according as it is potential. Whence this potentiality is not in God, but only active power.
Reply Obj. 2: Whenever act is distinct from power, act must be nobler than power. But God's action is not distinct from His power, for both are His divine essence; neither is His existence distinct from His essence. Hence it does not follow that there should be anything in God nobler than His power.