The Royal Road to the Criminal Law’s Concept of the Psychology of Persons

Abstract

One of the most famous excuses from responsibility and defenses to criminal liability is insanity. The doctrines of insanity are the royal road to grasping the nature of personhood presupposed by both morality and the criminal law. This is because the insane are thought to lack that which makes us accountable agents. The doctrines defining legal insanity are thus examined at some length, probing such doctrines for their suppositions about what psychological characteristics sane persons must possess to be responsible agents. Considerable stripping away from standard doctrines of insanity is needed to reveal the defense’s presuppositions about personhood and moral agency. For those standard doctrines treat insanity as if it were an ordinary excuse like mistake or coercion, just one incidentally limited to those offenders who are mentally ill. Whereas in fact insanity excuses independently of both the cognitive excuses of mistake and of the volitional excuses of coercion, and it does so because of the defense’s central focus on mental illness. Because of their mental illness those who are legally insane lack something more basic than the cognitive and volitional defects on which the defenses of mistake and coercion are based; those who are legally insane lack the moral agency possessed by sane adult persons. This is why this sui generis excuse of insanity affords such a unique opportunity to probe law and morality’s suppositions of what persons must be like to be responsible agents.