The wicked legal system, one whose laws have been made the instrument of a repugnant moral ideology, has played an important part in recent jurisprudential debate. This factor seems clearly to support the argument of legal positivists, who insist on a distinction between law and morality, and to be an insurmountable obstacle to critics of positivism, who reject that distinction. In evaluating this debate, Hard Cases in Wicked Legal Systems provides a detailed study of judicial interpretations of the apartheid laws of South Africa and a brief study of recent English Judicial decisions, mainly on statutes and executive decisions dealing with matters of state security. Dyzenhaus' study is highlighted by the surprising conclusion that positivism does not produce healthy legal practice. This penetrating study will be of particular interest to jurists and legal philosophers, political theorists, and administrative and constitutional lawyers.