French philosopher who became famous for his thesis on the rights of property in connection with taxation, which he held to be arbitrary and therefore illegal. For the thesis he was censured by the French Parlement.

After the French Revolution he was appointed professor of logic at the École Normale and spent the rest of his life in various teaching posts. He became a member of the Académie des Sciences Morales et Politiques in 1833.

Although he was essentially a follower of Étienne Bonnot de Condillac, who held that the source of all knowledge is sense perception, he took issue with several points of Condillac's doctrine, maintaining that some functions of the mind originate from within the mind itself. His major works include Projet d'éléments de métaphysique (1793; “Elements of Metaphysics”), Les Paradoxes de Condillac (1805; “The Paradoxes of Condillac”), and Leçons de philosophie (1815–18; “Lessons on Philosophy”), an extremely popular work in his day. He also edited the works of Condillac (1795).