Aristotle,
The Ethics of Aristotle
“ How can a man know what is good or best for him, and yet chronically fail to act upon his knowledge? Socrates was driven to the paradox of denying the possibility, but the facts are too strong for him. Knowledge of the right rule may be present, nay the rightfulness of its authority may be acknowledged, and yet time after time it may be disobeyed; the will may be good and yet overmastered by the force of desire, so that the act done is contrary to the agent’s will. Nevertheless the act may be the agent’s, and the will therefore divided against itself. ”
