Condillac, Étienne Bonnot de Mably de

Born Sept. 30, 1715, in Grenoble; died Aug. 3, 1780, in Beaugency. French Enlightenment philosopher; member of the Académic Françhise (1768). Brother of G. de Mably. Tutor to the grandson of Louis XV, the Duke of Parma, in Parma (1758–67).

Condillac began his literary activity in the mid-1740’s. He became acquainted with Diderot’s circle, and later he contributed to the Encyclopedia. Under the direct influence of the English philosopher J. Locke, he developed a sensationalist theory of knowledge. In his chief philosophical work, A Treatise on Sensations (1754; Russian translation, 1935), Condillac endeavored to find in sensations the roots of all man’s knowledge and spiritual abilities (thought, will, feelings, imagination, memory, and ability to concentrate, for example). Rejecting the Cartesian theory of innate ideas, he believed that the development of man’s abilities is determined exclusively by experience and lessons— that is, by upbringing and education. He was one of the founders of associational psychology. In political economy he developed a critique of the Physiocrats.

Although Condillac was not a materialist, his sensationalism and his critique of 17th-century idealist metaphysics (for example, the teachings of N. Malebranche and G. Leibniz) directly influenced the development of French materialism. His logic was extremely popular from the end of the 18th century through the early 19th. Condillac included mathematics in the discipline of logic, which he defined as the general grammar of all signs (The Language of Calculus, 1798).