Jean-Baptiste Le Rond d'Alembert

Profession: Enlightenment Philosopher

Biography: Jean-Baptiste Le Rond d'Alembert was a French mathematician, physicist, and philosopher. He was one of the leading figures of the French Enlightenment and is best known for his work in mathematics and his contributions to the famous Encyclopédie.

Born in Paris, d'Alembert was born an illegitimate child and abandoned by his parents on the steps of the Saint-Jean-le-Rond de Paris church, from which he derived his surname. He was ultimately cared for by the wife of a glazier and received a good education, with his father secretly providing for him while avoiding any official paternity.

D'Alembert first gained recognition for his work in mathematics and mechanics, particularly fluid dynamics and the theory of probability. In 1743, he published Traité de dynamique, in which he introduced d'Alembert's principle, a fundamental theorem in physics that provides a dynamic formulation of Newton's laws of motion. This work was crucial in the development of classical mechanics.

He was also deeply involved in the intellectual movement of the Enlightenment. Along with Denis Diderot, d'Alembert was a leading figure in the creation of the Encyclopédie, one of the most significant accomplishments of the Enlightenment era. This vast compilation of knowledge aimed to disseminate the scientific and philosophical ideas of the Enlightenment and challenge the dogmas of the religious and political establishment. D'Alembert wrote the work's famous Preliminary Discourse, which served as an introduction and overview of the project's goals and principles.

Born: November 16, 1717
Birthplace: Paris, France
Star Sign: Scorpio

Died: October 29, 1783 (aged 65)
Cause of Death: Urinary bladder illness