GABRIEL BONNOT DE, a French abbé, and brother of Condillac, was born at Grenoble on 14th March 1709. After receiving his education from the Jesuits in Lyons, he repaired to Paris, and, at the instance of his kinsman, the Cardinal De Tencin, entered the theological college of St Sulpice. No sooner, however, had he reached the rank of sub-deacon, than he threw aside the studies proper to his order, and devoted all his time to profane literature. His first work, Parallele des Romans et des Français par Rapport au Gouvernement (Paris, 1740), met with great success, and led to his being appointed secretary to the Cardinal De Tencin, at that time minister. In the discharge of his new office, Mably collected the greater part of that political information which he afterwards embodied in his Droit Public de l'Europe fondé sur les Traités, published in 1748, and reprinted with additions and improvements in 1754 and 1764. In 1743, after a series of secret negotiations, he concluded with the Prussian ambassador at Paris a treaty against Austria; and in 1746 he drew up the instructions for the French minister at the congress of Breda. Soon afterwards a quarrel with the cardinal induced Mably to retire into private life, and devote his time entirely to study. He died at Paris in 1785. His principal works are,—Observations sur l'Histoire de la Grèce, and Observations sur les Romains, 1751; Principes des Négociations, La Haye, 1757; Entretiens de Phocion sur le Rapport de la Morale et de la Politique, 1763; Observations sur l'Histoire de France, Genève, 1765, reprinted, with notes by Guizot; De la Legislation, ou Principes des Lois, Amsterdam, 1776; De la Maniere d'écrire l'Histoire, 1782; and Observations sur le Gouvernement et les Lois des Etats-Unis d'Amérique, 1784. His entire works were published by Abbé Brizard, in 15 vols. 8vo, 1794. Mably was an advocate for equality in rank and community in property. Sparta, under the legislation of Lycurgus, was his model of a government.