The Modern Foundation for the Insanity Defense: The Cases of James Hadfield (1800) and Daniel McNaughtan (1843)

Abstract

The modern foundation for the insanity defense was put in place during the first half of the nineteenth century, between the years 1800 and 1843. During this brief period the reaction to the acquittals by reason of insanity of James Hadfield (1800) and Daniel McNaughtan (1843) shaped the present function and administration of the insanity defense in the Anglo-American world. In the case of Hadfield, the reaction of the House of Commons to his acquittal led to the passage of the automatic confinement statutes that now accompany a successful plea of insanity in most jurisdictions. In McNaughtan's case, the reaction of the House of Lords to his acquittal led to the establishment of the famous right-from-wrong test of criminal responsibility that bears his name.