Nicene and Post-Nicene Fathers: Series I/Volume I/Confessions/Book VIII/Chapter 9
Chapter IX.—That the Mind Commandeth the Mind, But It Willeth Not Entirely.
21. Whence is this monstrous thing? And why is it? Let Thy mercy shine on me, that I may inquire, if so be the hiding-places of man’s punishment, and the darkest contritions of the sons of Adam, may perhaps answer me. Whence is this monstrous thing? and why is it? The mind commands the body, and it obeys forthwith; the mind commands itself, and is resisted. The mind commands the hand to be moved, and such readiness is there that the command is scarce to be distinguished from the obedience. Yet the mind is mind, and the hand is body. The mind commands the mind to will, and yet, though it be itself, it obeyeth not. Whence this monstrous thing? and why is it? I repeat, it commands itself to will, and would not give the command unless it willed; yet is not that done which it commandeth. But it willeth not entirely; therefore it commandeth not entirely. For so far forth it commandeth, as it willeth; and so far forth is the thing commanded not done, as it willeth not. For the will commandeth that there be a will;—not another, but itself. But it doth not command entirely, therefore that is not which it commandeth. For were it entire, it would not even command it to be, because it would already be. It is, therefore, no monstrous thing partly to will, partly to be unwilling, but an infirmity of the mind, that it doth not wholly rise, sustained by truth, pressed down by custom. And so there are two wills, because one of them is not entire; and the one is supplied with what the other needs.