Legal Insanity and Moral Knowledge
Katrina L. Sifferd
Abstract
This chapter argues that a successful plea of legal insanity ought to rest upon proof that a criminal act is causally related to symptoms of a mental disorder. Diagnosis of a mental disorder can signal to the court that the defendant had very little control over relevant moral ignorance or incompetence. Must we draw the same conclusion for defendants who lack moral knowledge due to miseducation or other extreme environmental conditions, unrelated to a mental disorder? Adults who were brainwashed as children, for example, might seem “insane” due to their lack of moral knowledge. However, since legal culpability rests on the capacity to understand the criminal law’s moral demands, to reflect on these demands across time, and to control one’s behavior in light of them, simple ignorance of morality’s demands does not excuse.