Intention, Excuse, and Insanity

Culpable intent has been a central element of mens rea in systems of criminal law since early times, but absence of culpable intent has not featured explicitly in most insanity tests since the time of McNaughtan. Most tests since then have been based on two other traditional elements of excuse: ignorance and compulsion (or duress). This chapter briefly reviews the background of this development and the reasons why absence of intent has not figured more prominently as an excusive factor in insanity defenses. Given the character of the offenses, the presence of criminal intent often seems indefeasible. It is argued that although many intentions may appear to be present, it is far from evident that those intentions or reasons that do have an efficacious or motivating role in the defendant’s actions, those reasons for which and those intentions with which the agent actually acted, are in fact criminal. For many relevant cases there is indeed intention that can account for the appearances and characteristics of intentionality in the defendant’s actions, but the efficacious intention is unconscious and nonculpable, and therefore not criminal-both because it is unconscious and because, in most cases, it is not a culpable intention. If the argument can be sustained, then the emphasis in determining absence of mens rea in some cases of insanity should shift from what the agent didn’t know or was (internally) compelled to do to what he intended; a position that seems more aligned with procedure in the ascertainment of legal responsibility elsewhere in the law.