South African criminal law has accepted that it is only fair to punish those who - if they do wrong - are responsible for doing wrong. Responsibility - that the accused must be blameworthy - finds expression in several specific requirements of South African criminal law: voluntariness, fault, and, in particular, capacity, into which the `insanity' defence falls. The Responsible Mind in South African Criminal Law critically analyses these requirements, and includes an empirical component in this analysis. The book also identifies and critically analyses the underlying model of responsibility adopted in our law and considers the alternatives. The conclusion from the empirical component and critical analysis is that the specific requirements are unclear and even incoherent, and that this is a function of the underlying model of responsibility, which identifies random capricious and arbitrary conduct as responsible conduct. Alternative models of responsibility are discussed, and a `compatibilist' model of reason sensitivity is selected as a better foundation for criminal responsibility. The Responsible Mind in South African Criminal Law discusses the implications of adopting this model for the various specific requirements of South African criminal law and proposes appropriate modifications. Ultimately a new model of criminal responsibility and a revised set of specific requirements are proposed, together with a proposed new statutory test for responsibility.