A Biographical Dictionary of Modern Rationalists/Alembert, Jean le Rond d'
Alembert, Jean le Rond d', Encyclopedist. B. (Paris) Nov. 16, 1717. He was a foundling, an illegitimate son of the Commissioner of Artillery (who was facetiously known as "Canon" Destouches, so that some have wrongly represented him as a priest), and he received the name of the church, St. Jean le Rond, near which he was found. He afterwards adopted the name of D'Alembert. His father settled an annuity on him, and he made brilliant studies in mathematics, law, and medicine. At college he wrote an essay on the Epistle to the Romans, which moved his clerical masters to declare him a second Pascal. From college he returned to the home of his foster-mother, the wife of a Parisian workman, and lived there in extreme simplicity for thirty years. In his zeal for mathematics he refused to take up a profession, and he soon became one of the most distinguished mathematicians in Europe. His Mèmoire sur le calcul integral (1739) was written in his twenty-third year. Three years later "he published his famous Traite de dynamique, which revolutionized his science. He was admitted to the French Academy in 1741, and won the Prize Medal of the Berlin Academy in 1746. In 1749 he solved the great problem of the precession of the equinoxes, and he explained the nutation of the earth's axis. Frederick of Prussia and Catherine of Russia in vain tried to seduce him from his humble lodging in Paris. He joined Diderot in issuing the Dictionnaire Encyclopedique, for which he wrote the preliminary discourse. In his letters to Voltaire, which j were edited by Condorcet, he says that " scepticism " (or what is now called Agnosticism), not Atheism, is the correct attitude; though he is confident that the "soul" is material and mortal. D'Alembert's character and simple, generous life were as great as his learning, and he sketches a high social morality in his Ếlements de philosophie. D. Oct 29 1783.