Book excerpt: Lawrie Reznek addresses these questions and more in his controversial investigation of the insanity defense in Evil or Ill? Drawing from countless intriguing case examples, he aims to understand the concept of an excuse, and explains why the law excuses certain actions and not others. In his easily accessible and elegant style, he explains that in law, there exists two excuses derived from Aristotle: the excuses of ignorance and compulsion. Reznek, however proposes a third excuse - the excuse of character change. In introducing this third excuse, Reznek raises a controversial possibility - the abolition of the insanity defence.