Although much human action serves as proof that irrational behavior is remarkably common, certain forms of irrationality--most notably, incontinent action and self-deception--pose such difficult theoretical problems that philosophers have rejected them as logically or psychologically impossible. Here, Mele shows that, and how, incontinent action and self-deception are indeed possible. Drawing upon recent experimental work in the psychology of action and inference, he advances naturalized explanations of akratic action and self-deception while resolving the paradoxes around which the philosophical literature revolves. In addition, he defends an account of self-control, argues that "strict" akratic action is an insurmountable obstacle for traditional belief-desire models of action-explanation, and explains how a considerably modified model accommodates action of this sort.