The Insanity Defense

Document Type

Book Chapter

Publication Date



This entry addresses the defense of legal insanity in Western law, with special reference to Anglo-American Law. The theoretical background of the defense and the tests and procedures used to adjudicate it are all covered. The entry argues that an insanity defense is morally required for justice in any fair system of criminal law and that lack of rational capacity is the most important justification for the defense.

Publication Title

The International Encyclopedia of Ethics

Publication Citation

In International Encyclopedia of Ethics, 2nd ed. (Hugh LaFollette et al. eds., Wiley-Blackwell 2019)

Full text not available in Penn Law Legal Scholarship Repository.