‘Weakness of the will’ is often used as a shorthand expression to describe a situation in which a person acts against his/her better judgement. This well-known phenomenon poses a serious philosophical problem because it questions deeply our self-understanding as rational agents. This volume offers the first comprehensive investigation into the roots of the present discussion of this subject. Four principal areas constitute the basic framework of the history of this problem: (1) the debate on akrasia in classical Greece; (2) the Christian understanding of weakness of will in late Antiquity; (3) the understanding of involuntary actions in the monastic period; (4) the scholastic controversy between ‘intellectualists’ and ‘voluntarists’ about the roots of human freedom. The book reconstructs the development of the problem within these frameworks and shows how the Greek and the Christian understanding of weakness of the will are intertwined. The final part offers an outlook on the present debate in view of these historical findings.