This book examines core issues related to legal insanity, integrating perspectives from psychiatry, law, and ethics. Various criteria for insanity are analyzed and recommendations for forensic psychiatric and legal practice are offered. Many legal systems have an insanity defense, in one form or another. Still, it remains unclear exactly when and why mental disorders affect a person’s moral or criminal responsibility. Questions addressed in this book include: Why should insanity be a component of our legal system? What should be the criteria for an insanity defense? What would be the reasons for abolishing it? Who should bear the burden of proof? Furthermore, the book discusses the impact neurosciences may have on psychiatric and psychological evaluations of defendants as well as on legal decisions about insanity.