Abstract

In akrasia, an agent intentionally acts against her own judgment about what it is best to do. This presents many puzzles for the understanding of human motivation. The Socrates of Plato's Protagoras, for example, denies this is possible because he claims that all action is motivated by an agent's belief about what is best. Plato himself seems to reject this view in the Republic, appealing to three distinct sources of motivation. This paper takes Plato's side in the general debate, arguing for a new tripartite moral psychology. Because the akratic acts for a reason but against the conclusion of her practical reasoning, there must be a way of acting for reasons other than through reasoning about them. This way is desire. But once there is a division between reason and desire, a third capacity is needed to solve conflicts that can arise between them, the will.