Alembert, Jean le Rond d' (zhäN lərôN` däläNbĕr`), 1717–83, French mathematician and philosopher. The illegitimate son of the chevalier Destouches, he was named for the St. Jean le Rond church, on whose steps he was found. His father had him educated. Diderot made him coeditor of the Encyclopédie Encyclopédie (äNsēklôpādē`), the work of the French Encyclopedists, or philosophes.
..... Click the link for more information. , for which he wrote the "preliminary discourse" (1751) and mathematical, philosophical, and literary articles. Discouraged, however, by attacks on his unorthodox views, he withdrew (1758) from the Encyclopédie. A member of the Academy of Sciences (1741) and of the French Academy (1754; appointed secretary, 1772), he was a leading representative of the Enlightenment Enlightenment, term applied to the mainstream of thought of 18th-century Europe and America.

Background and Basic Tenets

The scientific and intellectual developments of the 17th cent.
..... Click the link for more information. . His writings include a treatise on dynamics (1743), in which he enunciated a principle of mechanics known as D'Alembert's principle D'Alembert's principle (dăl`əmbârz')
..... Click the link for more information. ; a work on the theoretical and practical elements of music (1759); and a valuable history of the members of the French Academy (1787).

Alembert, Jean Le Rond d'

(born , Nov. 17, 1717, Paris, France—died Oct. 29, 1783, Paris) French mathematician, scientist, philosopher, and writer. In 1743 he published a treatise on dynamics containing “d'Alembert's principle,” relating to Isaac Newton's laws of motion. He developed partial differential equations and published findings of his research on integral calculus. He was associated with the Encyclopédie of Denis Diderot from c. 1746 as editor of its mathematical and scientific articles; he contributed articles on music as well, and he also published treatises on acoustics. He was elected to the Académie Française in 1754.