Definition
A person, historically assumed male, who is insane — particularly one experiencing mania or acute mental disorder. Not a term of art in either law or medicine. Courts and legal writers used it loosely to describe a person whose mental condition rendered them legally incompetent to act, contract, stand trial, or be held criminally responsible. Because it lacks a precise clinical or legal definition, the term functioned as a popular shorthand for insanity rather than a distinct legal category. Its legal significance, such as it is, runs entirely through the doctrine of insanity.
Common Language
Modern common usage (Wiktionary): A man who is insane or mentally disturbed; also, colloquially, a person who makes reckless or daring decisions — a daredevil.
Historical common usage (Webster's 1913): A man who is mad; a lunatic; a crazy person. Coleridge defined a madman as one who mistakes his thoughts for persons and things.
The gap between common and legal meaning here runs in the opposite direction from most entries: the legal meaning is actually narrower and more cautious than the common one. Everyday usage has expanded "madman" to cover recklessness or daring behavior having nothing to do with mental illness. Legal usage, while itself imprecise, always anchored the term to genuine mental disorder. A researcher encountering "madman" in a legal source should not read it as mere hyperbole — it signals an underlying insanity question with substantive legal consequences.
Common Confusion
MADMAN vs. IDIOT: These were treated as distinct conditions in older law and medicine. Black's specifically notes that "madman" was held inapplicable to idiots, citing Commonwealth v. Haskell. An idiot, in the historical legal sense, was a person born without ordinary mental capacity — a congenital condition. A madman was understood to have lost or suffered disruption of mental faculties, often episodically. The distinction mattered for guardianship, criminal responsibility, and testamentary capacity. Modern law has largely abandoned both terms in favor of clinical and statutory definitions, but the distinction appears repeatedly in historical sources and must not be collapsed when reading older cases or treatises.
MADMAN vs. LUNATIC: Also technically distinct in historical usage. A lunatic was sometimes understood as a person whose madness was intermittent — lucid intervals were legally significant because acts performed during such intervals could be binding. A madman was sometimes used to suggest a more continuous or acute condition. In practice, courts and writers used the terms interchangeably, and the distinction rarely held in application.
Why It Matters in Research
Researchers will encounter "madman" almost exclusively in historical sources — cases, statutes, and treatises predating the twentieth century's shift toward clinical and statutory language. The term is not used in modern legal writing.
The critical navigational point: "madman" in any legal source is a pointer, not a terminus. Bouvier's entry consists entirely of a cross-reference to insanity, which is the correct instinct. Any legal question touching a person described as a madman — capacity to contract, criminal liability, testamentary capacity, guardianship — must be researched under insanity, mental incompetency, and the specific doctrine at issue. The word itself carries no independent legal freight.
Researchers working in criminal law history should note the overlap with early formulations of the insanity defense. The "wild beast" standard articulated in eighteenth-century English cases used language essentially synonymous with "madman" — a person so disordered as to lack reason altogether. These formulations predate the M'Naghten rules and used popular rather than clinical vocabulary throughout.
In property and probate contexts, historical sources describing a testator or grantor as a "madman" raise capacity questions that turn on the law of insanity at the time of the instrument. The applicable standard varied by jurisdiction and era, and the label alone tells a researcher nothing about whether the legal test for incapacity was met.
One practical trap: older digest systems and indices may not cross-reference "madman" entries to mental incompetency or insanity headings consistently. If a term search in a historical digest or reporter index returns thin results, search the underlying doctrinal terms directly.
Historical Dictionary Support
Black's and Bouvier's agree on the essential point: "madman" is not a technical term and does not carry independent legal meaning. Bouvier dispenses with it in a single cross-reference. Black's is slightly more expansive, noting the connection to mania and flagging the idiot distinction with a citation, but its closing instruction — "See INSANITY" — arrives at the same place.
What both sources do not address is the term's gendered framing. Historical legal sources used "madman" as the default, with "madwoman" appearing occasionally but inconsistently. This linguistic pattern reflects the broader exclusion of women from full legal personhood in the periods when these sources were written, not a substantive legal distinction based on sex.
Black's note that the term "is incapable of being applied with scientific precision" is worth taking seriously as a research caution. Courts that used "madman" in opinions were applying a lay vocabulary to what were ultimately medical and legal judgments. The word signals the presence of an insanity issue; it does not resolve it.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Insanity and Criminal Responsibility; Mental Incompetency and Legal Capacity