Domat studied the humaniora in Paris, where he befriended Blaise Pascal, and later law at Bourges. After his promotion in 1645, he practised law in Clermont and was appointed a crown prosecutor there in 1655. In 1683, he retired from this office with a pension from Louis XIV to concentrate on his scholarship.
Together with d'Autreserre, Favre and the Godefroy brothers, Domat was one of the few later French scholars of Roman law of international significance. His principal work, Les lois civiles dans leur ordre naturel (1689, 68 later editions) was to become one of the principal sources of the ancien droit on which the Code Napoleon was later founded. In line with earlier Humanist attempts to transform the seemingly random historical sources of law into a rational system of rules, it presented the contents of the Codex Iustinianis in the form of a new system of natural law. After Doneau's more thorough but less consistent Commentarii iuris civilis (1589), the Lois were the first work of this type of pan-European significance.
He was closely in sympathy with the Port-Royalists, and on Pascal's death, he was entrusted with his private papers.
He is principally known from his elaborate legal digest, in three volumes, under the title of Lois civiles dans leur ordre naturel (1689), an undertaking for which Louis XIV settled on him a pension of 2000 livres. A fourth volume, Le Droit public, was published in 1697, a year after his death.
This is one of the most important works on the science of law that France has produced. Domat endeavoured to found all law upon ethical or religious principles, his motto being "L'homme est fait par Dieu et pour Dieu.
The major work of Jean Domat, The civil Laws in their natural order, marked profoundly the doctrine of the ancient French law. It was an attempt to establish a system of French law on the basis of moral principles. Supporter of a Cartesian juridical order, Domat builds a work of private law hard marked by a Jusnaturaliste and Romanist footprint. Domat's grand plan was to set out a scheme of Christian law for France in a rationalist view.
He performed the bold and extraordinary feat of recasting the entire mass of existing Roman law and restating it concisely in what he believed to be a rational system. Having organized and condensed the principles of civil law, this work, well-known by the fathers of Code, brings a big part of the structure of the Napoleonic code.
By its will to display law, to rationalize it, following Grotius, Domat brings an intellectual tool necessary to codify. The thought of Domat is the second authority, in importance, of the Civil Code of Lower Canada beside the work of Pothier.
Besides the Lois Civiles, Domat made in Latin a selection of the most, common laws in the collections of Justinian I, under the title of Legum delectus (Paris, 1700; Amsterdam, 1703); it was subsequently appended to the Lois civiles. His works have been translated into English. Domat died in Paris on the 14th of March 1696.
In the Journal des savants for 1843 are several papers on Domat by Victor Cousin, giving much information not otherwise accessible.
- IGLESIAS, A. "Philosophy and Law in Jean Domat" (Spanish), Ph.D. Legal history and philosophy-human rights, Thesis, 2009, U. Carlos III de Madrid.
- D. Gilles, Jean Domat's juridical thought. From Grand siècle to civil french Code, (in French), Ph. D. Law, Thesis, Aix-Marseille III, 1994.
- D. Gilles, « Les Lois civiles de Jean Domat, prémices des Codifications ? Du Code Napoléon au Code civil du Bas Canada », Revue juridique Thémis, Montréal, n. 43-1, 2009, pp. 2–49.
- Holthöfer, Ernst (2001). "Domat, Jean". In Michael Stolleis (ed.). Juristen: ein biographisches Lexikon; von der Antike bis zum 20. Jahrhundert (in German) (2nd ed.). München: Beck. p. 180. ISBN 3-406-45957-9.