After documenting the mention of insanity in the Bible and Talmud, the writings of Hippocrates and Plato, and Shakespearean plays such as Hamlet, the author contrasts the viewpoints on the insanity defense of such scholars as Isaac Ray, Karl Menninger, Sigmund Freud, Ralph Slovenko, Thomas Szasz, and Alan Stone. The author then presents his own belief that psychiatric testimony is relevant in the courtroom, but not without limitation. He argues that the clinician's main value to the court is to provide descriptive symptoms that document a patient's severe mental illness and how the illness affected the individual's behavior. He acknowledges the clinician is much less capable to explain the cause of the deviant behavior. He supports the insanity defense as valid for persons whose mental illness was directly related to a criminal action. 54 references.