French philosopher and physiologist noted for Rapports du physique et du moral de l'homme (1802; “Relations of the Physical and the Moral in Man”), which explained all of reality, including the psychic, mental, and moral aspects of man, in terms of a mechanistic Materialism.

Cabanis' early interest in poetry and medicine and a budding political career were eventually abandoned in favour of philosophical science. Nevertheless, he attended the Comte de Mirabeau in his final illness as friend and private physician. He also moved in the company of Diderot, d'Alembert, Condorcet, Condillac, and d'Holbach and knew Benjamin Franklin and Thomas Jefferson during their stay in Paris.

For Cabanis, life was merely an organization of physical forces; thought was the result of “secretions” in the brain analogous to the liver's secretion of bile; behaviour depended upon the arrangement of natural elements. The soul was superfluous since consciousness was merely an effect of mechanistic processes, and sensibility, the source of intelligence, was a property of the nervous system. At the end of his life, Cabanis viewed the ego as immaterial and immortal but saw in this view no incompatibility with his earlier theories.