The American Journal of Psychiatry

L ong before there was psychiatry, there was the insanity defense. The idea that the insane should not be punished for otherwise criminal acts began to develop in the twelfth century as part of the more general idea that criminal punishment should be imposed only on persons who were morally blameworthy. In the thirteenth century, Bracton, the first medieval jurist to deal with the subject of insanity and crime’ stated, “For a crime is not committed unless the will to harm be present.” The earliest documented case of a jury acquittal on grounds of unsound mind occurred in 1505 (1). In his treatise on the History of the Pleas of the Crown (2) published posthumously in 1736, England’s Lord Mathew Hale explained that the insanity defense was rooted in the fundamental moral assumptions of the criminal law: