How does the law regard and define mental incompetence, when faced with the problem of meting out justice? To what extent has the law relied on extra-legal authorities--be they religious or scientific--to frame its own categories of mental incompetence and madness? Wild Beasts and Idle Humours takes us on an illuminating journey through the changing historical landscape of human nature and offers an unprecedented look at the legal conceptions of insanity from the pre-classical Greek world to the present. Although actual trial records are either totally lacking or incomplete until the eighteenth century, there are other sources from which the insanity defenses can be constructed. In this book Daniel N. Robinson, a distinguished historian of psychology, pores over centuries of written law, statements by legal commentators, summaries of crimes, and punishments, to glean from these sources an understanding of epochal views of responsibility and competence. From the Greek phrenesis to the Roman notions of furiosus and non compos mentis, from the seventeenth-century witch trials to today's interpretation of mens rea, Robinson takes us through history and provides the intricate story of how the insanity defense has been construed as a meeting point of the law and those professions that chart human behavior and conduct: namely religion, medicine, and psychology. The result is a rare historical account of "insanity" within Western civilization. Wild Beasts and Idle Humours will be essential reading for anyone interested in the evolution of thinking not merely about legal insanity but about such core concepts as responsibility, fitness for the rule of law, competence to enter into contracts and covenants, the role of punishments, and the place of experts within the overall juridical context.