REASON

10 definitions found across Law Mind sources

REASONAuthored
The Law Mind • 1198 words
Definition
In law, "reason" operates primarily as a foundational cognitive concept rather than a term of art. It refers to the faculty of the mind by which a person distinguishes truth from falsehood, right from wrong, and draws inferences from facts or propositions. This capacity for rational thought underlies a vast range of legal doctrines — from criminal responsibility to contract formation to standards of care. Reason functions in legal discourse in two principal registers: 1. As a mental faculty. The presence or absence of reason determines legal capacity. A person deprived of reason — whether by mental illness, intoxication, or developmental incapacity — may lack the ability to form criminal intent, enter into binding contracts, or execute a valid will. This is reason in the cognitive or psychological sense. 2. As a standard of justification. Courts and legislatures routinely invoke "reason" (and its derivative, "reasonable") as a normative benchmark — a standard against which conduct, belief, or judgment is measured. In this register, reason does not mean the private mental faculty of any particular person, but rather the generalized rational judgment of a legally hypothesized actor: the reasonable person, reasonable care, reasonable doubt, reasonable notice.
Common Language
Modern common usage (Wiktionary): A cause, motive, or explanation offered in support of an opinion or action; also the capacity for rational thought. Historical common usage (Webster's 1913): A thought or consideration offered in support of a determination or opinion; a just ground for a conclusion or action; an efficient or final cause; principle. The common and legal uses of "reason" are not sharply divergent — law inherited the term from ordinary English and from classical philosophy. The meaningful gap lies in degree and consequence: in daily speech, reason is a loose synonym for explanation or motive. In law, the presence or absence of reason is a threshold determination that triggers or forecloses entire doctrines. Equally important, law has transformed reason's adjective form — "reasonable" — into one of the most heavily litigated words in the legal lexicon, carrying normative and objective weight that the common usage does not.
Common Confusion
"Reason" should not be confused with "motive" or "intent," though all three concepts intersect in criminal law. Motive is the underlying impulse or goal that prompts action. Intent is the conscious purpose to bring about a particular result. Reason, in the mental faculty sense, is the broader cognitive prerequisite for either — a person must possess reason before the law will attribute motive or intent to them at all. Separately, researchers should not conflate "reason" as a noun (the faculty, a justification) with "reasonable" as a legal standard. The adjective form has developed its own extensive body of doctrine almost entirely independent of the noun.
Why It Matters in Research
This term is a gateway, not a destination. Researchers who search for "reason" in historical corpus sources will encounter it in at least three distinct legal contexts that require separate treatment: First, in competency and capacity doctrine. Historical sources use "reason" as a near-synonym for legal sanity. Pre-20th-century cases and treatises routinely ask whether a defendant "possessed his reason" rather than whether he met a modern competency standard. The vocabulary has shifted; the underlying inquiry persists. Researchers tracing insanity defenses, testamentary capacity, or contractual incapacity should be alert to this usage in sources from the 18th and 19th centuries. Second, as a source of law. The maxim "ratio in jure aequitas integra" — reason in law is complete equity — reflects a tradition in which reason itself was treated as a source of legal authority, particularly in equity and natural law argument. Bouvier and early American treatise writers invoke this directly. Researchers working in early republic legal thought or natural law traditions will find "reason" functioning as a jurisprudential category, not merely a cognitive description. Third, as the root of the "reasonable" standard. Nearly every conditional section in this dictionary that involves reasonableness — reasonable care, reasonable doubt, reasonable person, reasonable notice — traces back to this noun. The corpus connections are dense. Researchers following a doctrine of reasonableness should treat this entry as an orienting node and then move immediately to the specific "reasonable" term at issue. The historical sources are sparse on this term precisely because it was considered foundational and self-evident. That sparseness is itself informative: "reason" was treated as a philosophical given, not a contested legal definition. Modern litigation over what is "reasonable" has in effect redistributed all the analytic weight that earlier law placed in the noun.
Historical Dictionary Support
The historical sources converge on the mental faculty definition but diverge in emphasis and ambition. Black's (1st Ed.) defines reason primarily through its forensic application — specifically, its connection to the standard of reasonable doubt, quoting a New Jersey case for the proposition that the jury must be brought to "moral certainty of the truth of the charge." This is characteristic of Black's approach: defining a foundational term by reference to its most litigated derivative. Bouvier offers the fullest treatment. He grounds the definition in Enlightenment epistemology ("that power by which we distinguish truth from falsehood and right from wrong"), cites the Encyclopédie, and explicitly invokes the natural law tradition with the maxim "Ratio in jure aequitas integra." His entry links reason directly to criminal responsibility and contractual capacity — noting that a person deprived of reason is not criminally responsible and cannot enter a contract. He also preserves the celebrated formulation that "reason is the soul of the law," a phrase that appears in Coke and recurs throughout early Anglo-American jurisprudence. Anderson's is the most candid of the sources: "Presents no meaning peculiar to jurisprudence." This is accurate as far as it goes. Anderson redirects readers to "Reasonable" and to "Ratio" — a useful cross-referencing instinct. His note that "reasonable" means "conformable to the requirements of law, sufficient, proper" signals that the real legal work is being done by the adjective. Black's (2nd Ed.) does not appear to carry a dedicated entry for "reason" as such; the source material provided pertains to adjacent headwords. This absence in the 2nd edition, compared to the 1st, may reflect editorial choices about which foundational terms warranted independent treatment. What the historical sources collectively miss is the transformation of "reasonable" into a freestanding, heavily structured legal standard during the late 19th and 20th centuries. The historical entries treat reason as a stable philosophical concept. They do not anticipate the doctrinal elaboration — the reasonable person standard in tort, the reasonableness review in constitutional law, the reasonable doubt instruction — that would occupy courts for the following century.
Encyclopedia Cross-Reference
The Law Mind Torts & Personal Injury Encyclopedia — Negligence: The Reasonable Person Standard The Law Mind Remedies & Equity Encyclopedia — The Lodestar Method: Reasonable Hours x Reasonable Rate The Law Mind Intellectual Property Encyclopedia — Reasonable Measures to Maintain Secrecy
Related Terms
Reasonable person standard — Reasonable doubt — Reasonable care — Sanity — Legal capacity — Competency — Intent — Motive — Natural law — Ratio (maxim) — Sound mind — Due care — Objective standard
REASONmain
Black's Law Dictionary • 1891
A faculty of the mind by which it distinguishes truth from falsehood, good from evil, and which enables the pos- sessor to deduce inferences from facts or from propositions. Webster. ing conviction to a moral certainty of the truth of the charge. 26 N. J. Law, 601, 615. A reasonable doubt is deemed to exist, within the rule that the jury should not convict unless satis- fied beyond a reasonable doubt, when the evidence is not sufficient to satisfy the judgment of the truth of a proposition with such certainty that a prudent man would feel safe in acting upon it in his own important affairs. 23 Ind. 170.
REASONmain
Black's Law Dictionary (2nd Ed.) • 1910
records, the burden is said to be real. Bell.— Real chymin. [L. Fr. In old English law. The royal way; the king's highway, (regia via.) —Real injury. In the civil law. An injury arising from an unlawful act, as distinguished -from a verbal injury, which was done by words. Hallifax, Civil Law, b. 2, c. 15, nn. 3, ‘4.—Real things, (or things real.) In common law. Such things as are permanent, fixed. and immovable, which cannot be carried out of their pace as lands and tenements: 2 BI. Comm. 5. Things substantial and immovable, and the rights and profits annexed to or issuing out of them. 1 Steph. Comm. 156. As to real “Action,” “Assets,” “Chattels,” “Composition,” “Contract,” “Covenant,” “Estate,” “Evidence,” “Issue,” ‘Obligation,” “Party,” “Poinding,” “Privilege,” ‘Property.” “Representative,” “Right,” “Security,” “Servitude,” “Statute,” “Warrandice,” and “Wrong,” see those titles. A faculty of the mind by which it distinguishes truth from falsehood, good from evil, and which enables the possessor to deduce inferences from facts or from propositions. Webster. Also an inducement, motive, or ground for action, as in the phrase “reasons for an appeal.” See ‘Nelson v. Clongland, 15 Wis. 398; Miller v. Miller, 8 Johns. (N. Y.) 77.
REASONmain
Anderson's Dictionary of Law • 1890
Presents no meaning peculiar to jurisprudence. Reasonable. Agreeable to sound reason, just, rational; also, conformable to the requirements of law, sufficient, proper: as, reasonable care, diligence, skill; reasonable cause, doubt, notice, part, time, qq. v. Compare RATIO; SANE.
REASONn.
Websters Unabridged Dictionary (1913) • 1913
A thought or a consideration offered in support of a determination or an opinion; a just ground for a conclusion or an action; that which is offered or accepted as an explanation; the efficient cause of an occurrence or a phenomenon; a motive for an action or a determination; proof, more or less decisive, for an opinion or a conclusion; principle; efficient cause; final cause; ground of argument. I'll give him reasons for it. Shak. The reason of the motion of the balance in a wheel watch is by the motion of the next wheel. Sir M. Hale. This reason did the ancient fathers render, why the church was called "catholic." Bp. Pearson. Virtue and vice are not arbitrary things; but there is a natural and eternal reason for that goodness and virtue, and against vice and wickedness. Tillotson. The faculty of capacity of the human mind by which it is distinguished from the intelligence of the inferior animals; the higher as distinguished from the lower cognitive faculties, sense, imagination, and memory, and in contrast to the feelings and desires. Reason comprises conception, judgment, reasoning, and the intuitional faculty. Specifically, it is the intuitional faculty, or the faculty of first truths, as distinguished from the understanding, which is called the discursive or ratiocinative faculty. We have no other faculties of perceiving or knowing anything divine or human, but by our five senses and our reason. P. Browne. In common and popular discourse, reason denotes that power by which we distinguish truth from falsehood, and right from wrong, and by which we are enabled to combine means for the attainment of particular ends. Stewart. Reason is used sometimes to express the whole of those powers which elevate man above the brutes, and constitute his rational nature, more especially, perhaps, his intellectual powers; sometimes to express the power of deduction or argumentation. Stewart. By the pure reason I mean the power by which we become possessed of principles. Coleridge. The sense perceives; the understanding, in its own peculiar operation, conceives; the reason, or rationalized understanding, comprehends. Coleridge. Due exercise of the reasoning faculty; accordance with, or that which is accordant with and ratified by, the mind rightly exercised; right intellectual judgment; clear and fair deductions from true principles; that which is dictated or supported by the common sense of mankind; right conduct; right; propriety; justice. I was promised, on a time, To have reason for my rhyme. Spenser. But law in a free nation hath been ever public reason; the enacted reason of a parliament, which he denying to enact, denies to govern us by that which ought to be our law; interposing his own private reason, which to us is no law. Milton. The most probable way of bringing France to reason would be by the making an attempt on the Spanish West Indies. Addison. Ratio; proportion. [Obs.] Barrow. By reason of, by means of; on account of; because of. "Spain is thin sown of people, partly by reason of the sterility of the soil." Bacon. In reason, In all reason, in justice; with rational ground; in a right view. When anything is proved by as good arguments as a thing of that kind is capable of, we ought not, in reason, to doubt of its existence. Tillotson. -- It is reason, it is reasonable; it is right. [Obs.] Yet it were great reason, that those that have children should have greatest care of future times. Bacon.
REASONv.
Websters Unabridged Dictionary (1913) • 1913
To exercise the rational faculty; to deduce inferences from premises; to perform the process of deduction or of induction; to ratiocinate; to reach conclusions by a systematic comparison of facts. Hence: To carry on a process of deduction or of induction, in order to convince or to confute; to formulate and set forth propositions and the inferences from them; to argue. Stand still, that I may reason with you, before the Lord, of all the righteous acts of the Lord. 1 Sam. xii. 7. To converse; to compare opinions. Shak.
REASONv.
Websters Unabridged Dictionary (1913) • 1913
To arrange and present the reasons for or against; to examine or discuss by arguments; to debate or discuss; as, I reasoned the matter with my friend. When they are clearly discovered, well digested, and well reasoned in every part, there is beauty in such a theory. T. Burnet. To support with reasons, as a request. [R.] Shak. To persuade by reasoning or argument; as, to reason one into a belief; to reason one out of his plan. Men that will not be reasoned into their senses. L'Estrange. To overcome or conquer by adducing reasons; -- with down; as, to reason down a passion. To find by logical process; to explain or justify by reason or argument; -- usually with out; as, to reason out the causes of the librations of the moon.
reasonnoun
Wiktionary (English) • 2026
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A cause: | That which causes something: an efficient cause, a proximate cause. | A cause: | A motive for an action or a determination. | A cause: | An excuse: a thought or a consideration offered in support of a determination or an opinion; that which is offered or accepted as an explanation. | A cause: | A premise placed after its conclusion. | Rational thinking (or the capacity for it); the cognitive faculties, collectively, of conception, judgment, deduction and intuition. | Something reasonable, in accordance with thought; justice. | Ratio; proportion.
Reasonname
Wiktionary (English) • 2026
Wiktionary contributorsCC BY-SA 4.0 • via Kaikki
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A surname.
reasonverb
Wiktionary (English) • 2026
Wiktionary contributorsCC BY-SA 4.0 • via Kaikki
Extracted and formatted for display by Law Mind. Source link opens the current Wiktionary page and its contributor history; it is not a frozen copy of this extract.
To deduce or come to a conclusion by being rational. | To perform a process of deduction or of induction, in order to convince or to confute; to argue. | To converse; to compare opinions. | To arrange and present the reasons for or against; to examine or discuss by arguments; to debate or discuss. | To support with reasons, as a request. | To persuade by reasoning or argument. | To overcome or conquer by adducing reasons. | To find by logical process; to explain or justify by reason or argument.

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