This book challenges the assumptions of modern criminal law that insanity is a natural, legally and medically defined phenomenon (covering a range of medical disorders). By doing so, it paves the way for a new perspective on insanity and can serve as the basis for a new approach to insanity in modern criminal law. The book covers the following aspects: the structure of the principle of fault in modern criminal law, the development of the insanity defense in criminal law, tangential in personam defenses in criminal law and their implications for insanity and the legal mechanism of reproduction of fault. The focus is on the Anglo-American and European-Continental legal systems. Given the attention consistently drawn by international and domestic events in this context, the book will be of interest to a broad and growing international audience.