Precisely so—for the hand’s movement is not what brings the key’s movement into existence; the two simply coincide. It has been demonstrated elsewhere that an agent must precede his effect in time, quite apart from whether he acts by choice.

That He acts by will furnishes a further proof. Whenever an act proceeds from His power and will, the act itself cannot be necessary to His Essence. Hence no specific act is essential to Him, none of the effects is essential to Him, and therefore none of them is eternal—which is exactly what had to be shown.

This argument is perfectly sound and cogent.

Should someone object, “A particular effect that is essential to the Essence could still be within His power and the object of His will,” we reply: In that case His very power and will would themselves have to be within power and will. If they are subject to the same power and will, causation and agency collapse into a vicious circle; if they are subject to another power and will, an infinite regress ensues in the chain of causes of the same type.

Both possibilities are flatly impossible according to plain reason and the agreement of the rational. The Essence would then require an eternal power and an eternal will, which could exist only through yet another eternal power and will, and those only through still another, ad infinitum. The agent would thus do nothing of powers and wills until He had already produced some powers and wills, leading to the conclusion that He would never act at all. This is the vicious circle at the very root of action and causation.