Jeffrey Dahmer tried to turn victims into sex slaves by injecting acid into their brains, strangled 17 men, had sex with the dead bodies, boiled their skulls, and ate their flesh. Despite this bizarre behavior, a jury did not accept a plea of not guilty by reason of insanity and sentenced him to 957 years in prison. With this anecdote, Lawrie Reznek introduces his philosophical quest to understand the difference between evil and illness, the insanity defense, and the role of psychiatrists in the courts. He examines the standard legal defenses of Durham and M’Naghten as well as that proposed by the American Law Institute. Using a multitude of case examples, he looks at specific excuses (such as automatism and intoxication) presented to the courts and explains how they do or do not fit into the standard defenses. He also distinguishes between legal and medical insanity.

This book is not a primer on forensic psychiatry, however. Reznek goes back to his roots as a philosopher to understand why, under certain circumstances, we excuse criminal behavior. He notes that one can perform an evil act such as murder without being an evil person, e.g., in self-defense. He demonstrates that the essential components of most excuses (i.e., that a person is not responsible if he was not in control of his actions or was ignorant of what he was doing) originate in the writings of Aristotle about ignorance and compulsion. Reznek clearly and cogently leads the reader to the conclusion, not previously addressed by philosophers or the law, that our judgment should be based on whether the offender is someone whose actions are consistent with his basically good character. Interestingly, after philosophically arriving at this conclusion, he demonstrates that, despite the legal rules, juries, using "folk psychology," already tend to ascribe responsibility to and punish those with evil characters and excuse good characters.

The book is divided into 13 short chapters plus an introduction and a conclusion. Each chapter is subdivided into sections addressing an issue and raising a question to be answered by the next section. Each chapter is succinctly summarized in a paragraph, and the conclusion pulls all of the ideas into a cohesive whole. In attempting to construct this thesis clearly, and perhaps to avoid scaring off readers with "heavy" philosophy, some of the sections seem a little repetitive. However, fascinating case examples and discussions of such issues as multiple personality disorder, the biology of evil, sexual sadism, and psychopathic personality disorder more than compensate. This is a fascinating book that requires us to question our ideas of causality and responsibility. I plan to suggest it to a patient who is still making excuses for abusive parents. I believe this will help her understand that when people choose to act in pursuit of their own selfish interests in a way that is indifferent to others, they are evil characters and are responsible for their behavior.