Diminished Capacity

Document Type

Book Chapter

Publication Date



Stress, intense emotion, mental disorder and defect, intoxication, trauma, and other causes of abnormal mental states can impair rationality and self-control, abilities which are thought crucial to ascriptions of moral responsibility. In addition to insanity, diminished capacity in its many incarnations is the major legal doctrine that responds to mental abnormality. After first briefly outlining preliminary assumptions about responsibility and criminal justice, this chapter defines diminished capacity's two variants: the mens rea and partial-responsibility variants. It then addresses in depth the justifications and implementation problems for each variant, with special attention to partial responsibility and the problematic issue of ‘internal coercion’ or ‘compulsion’. It concludes with a discussion of difficult special issues.


moral responsibility, insanity, means rea, partial-responsibility, internal coercion, compulsion, criminal law

Publication Title

Action and Value in Criminal Law