Abstract
Some philosophers have argued that the psychopath serves as the ultimate test of the limits of moral responsibility. They hold that the psychopath lacks a deep knowledge of right and wrong, and that Kant’s ethics arguably offers the most plausible account of this moral knowledge. On this view, the psychopath’s lack of moral understanding is due to a cognitive failure involving practical reason. I argue that the deep knowledge of right and wrong consists of emotional and volitional components in addition to a cognitive one. Hence it is mistaken to claim that the psychopath’s moral deficiency is due solely to a cognitive failure, or that his lack of the deep knowledge of right and wrong can be explained entirely in terms of a defect of practical reason. I refer to empirical research to show that the Kantian model of practical reason does not provide a satisfactory account of responsibility of the psychopath in particular or of moral agents in general. On the basis of both philosophical and empirical considerations, I argue that the psychopath is at least partly responsible for his behaviour.