Ever since the 1970s the elaboration of a philosophical theory of the subjective basis of criminal liability has been attempted in the Anglo-American world, often in the context of the discussions on the problem of the responsibility of the mentally ill offender. Michael S. Moore's (and others') theory of capacity for rational choice seemed to prevail in the debate. A brief history of the birth and the development of this theory is proposed in this paper, together with an attempt to weight its pros and contras. The basic claim is, despite its great intuitiveness and its good applicability to many moral and legal cases, the theory of capacity for rational choice is not likely to play the role of general theory of personal responsibility its proponents sometimes attribute to it. As it is displayed by the results of many present debates on some particular cases, rational capacity theory is in fact not likely to offer interesting solutions to many significant cases.