A legal maxim is an established principle or proposition of law, and a species of aphorism and general maxim. The word is apparently a variant of the Latin maxima, but this latter word is not found in extant texts of Roman law with any denotation exactly analogous to that of a legal maxim in the Medieval or modern definition, but the treatises of many of the Roman jurists on regular definitiones and sententiae iuris are to some degree collections of maxims. Most of the Latin maxims originate from the Medieval era in European states that used Latin as their legal language.

The attitude of early English commentators towards the maximal of the law was one of unmingled adulation. In Thomas Hobbes, Doctor and Student (p. 26), they are described as of the same strength and effect in the law as statutes. Francis Bacon observed in the preface to his collection of maxims: The use of maxims will be "in deciding doubt and helping soundness of judgment, but, further, in gracing argument, in correcting unprofitable subtlety, and reducing the same to a more sound and substantial sense of law, in reclaiming vulgar errors, and, generally, in the amendment in some measure of the very nature and complexion of the whole law".^[1]^[2]

A similar note was sounded in Scotland; and it has been well observed that a glance at the pages of Morison's Dictionary of Decisions or at other early reports will show how frequently in the older Scots law questions respecting the rights, remedies and liabilities of individuals were determined by an immediate reference to legal maxims.

In later times, less value has been attached to the maxims of the law, as the development of civilization and the increasing complexity of business relations have shown the necessity of qualifying the propositions which they enunciate. But both historically and practically, they must always possess interest and value.

The principal collections of legal maxims

Canon law

Regulæ Juris of Boniface VIII (1298)

English law

Francis Bacon, Collection of Some Principal Rules and Maxims of the Common Law (1630);
Noy, Treatise of the principal Grounds and Maxims of the Law of England (1641, 8th ed., 1824);
Wingate, Maxims of Reason (1728);
Francis, Grounds and Rudiments of Law and Equity (2nd ed. 1751);
Lofft (annexed to his Reports, 1776);
Branch, Principia Legis Et Æquitatis (T. A. White, 1824)
Broom, Legal Maxims (7th ed. London, 1900).

Scots law

Lord Trayner, Latin Maxims and Phrases (2nd ed., 1876);
Stair, Institutions of the Law of Scotland, with Index by More (Edinburgh, 1832).

American treatises

John Bouvier, A Law Dictionary: Adapted to the Constitution and Laws of the United States of America and of the Several States of the American Union, Revised Sixth Edition, 1856. A long list of maxims is contained in the section for the letter "M".
Burrill, A New Law Dictionary and Glossary (J. S. Voorhies, 1860)
A. I. Morgan, English Version of Legal Maxims (Cincinnati, 1878);
S. S. Peloubet, Legal Maxims in Law and Equity (New York, 1880).
Anonymous, Latin for without name, Chapter II, "A Collection of over one thousand Latin maxims, with English translations, explanatory notes, and cross-references", Sweet and Maxwell, 1915.

Notes

^ "The Maxims of the Law" is combined with a tract entitled The Use of the Common Law, for preservation of our Persons, goods, and good Names in a book entitled The Elements of the Common Lawes of England.
^ "The Elements of the Common Lawes of England". The Works of Francis Bacon. Murphy. 1887. p. 221.

This article incorporates text from a publication now in the public domain: Renton, Alexander Wood (1911). "Maxims, Legal". In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 17 (11th ed.). Cambridge University Press. pp. 925–926.