The question of excusing in law has been the subject of different philosophical theories of responsibility. These theories attempt to shed light on the nature and function of legal excuses and to justify their role in the criminal justice system. This paper examines the issue of excusing in law from two theoretical standpoints: the character theory and the choice theory of responsibility. The two theories differ on the kinds of causes of action they each find to provide the basis for holding people responsible. The character theory focuses on character, the choice theory on choice and the capacity to choose. Following a brief introduction in which the fundamental distinction between justification and excuse is outlined, the character theory of responsibility is explained with special attention being paid to the work of George Fletcher, which has made a significant impact on the field of criminal law philosophy in recent years. Then follows a critical discussion of the choice theory as elaborated by H.L.A. Hart, one of the most influential legal theorists of our times. The paper concludes that the character theory of responsibility, by drawing attention to what lies behind and motivates actual choices, offers a better basis for interpreting the moral significance of human actions and for explaining our actual blaming judgements regarding those actions.