Cabanis was closely associated with the group of thinkers known as the
idéologues, who were active during the French Revolutionary and early Napoleonic periods. Together with figures such as
Antoine Destutt de Tracy, one of the leading theorist of the group, founder of
idéologie and his close friend, Cabanis contributed to an intellectual project that aimed to ground the study of ideas in a systematic, scientific analysis of sensation and human faculties, closely linked to physiology and early psychology. A complete edition of Cabanis's works was begun in 1825, and five volumes were published. His principal work, ''Rapports du physique et du moral de l'homme
(On the relations between the physical and moral aspects of man'', 1802), consists in part of memoirs, read in 1796 and 1797 to the institute, and is a sketch of physiological
psychology. Psychology is with Cabanis directly linked on to
biology, for sensibility, the fundamental fact, is the highest grade of life and the lowest of intelligence. All the intellectual processes are evolved from sensibility, and sensibility itself is a property of the
nervous system. The
soul is not an entity, but a faculty; thought is the function of the
brain. Just as the
stomach and
intestines receive food and digest it, so the brain receives impressions, digests them, and has as its organic secretion, thought. Alongside this
materialism, Cabanis held another principle. He belonged in biology to the vitalistic school of
G.E. Stahl, and in the posthumous work,
Lettre sur les causes premières (1824), the consequences of this opinion became clear. Life is something added to the organism: over and above the universally diffused sensibility there is some living and productive power to which we give the name of Nature. It is impossible to avoid ascribing both intelligence and will to this power. This living power constitutes the ego, which is truly immaterial and immortal. Cabanis did not think that these results were out of harmony with his earlier theory. His work was highly appreciated by the philosopher
Arthur Schopenhauer, who called his work "excellent". He was a member of the masonic lodge
Les Neuf Sœurs from 1778. In 1786, Cabanis was elected an international member of the
American Philosophical Society in Philadelphia. ==Evolution==