Alembert, Jean Le Rond D
Alembert, Jean Le Rond D', a French mathematician and philosopher of the empirical school, was born in Paris, Nov. 16, 1717, and died in the same city Oct. 29, 1783. He was the illegitimate child of the Chevalier Destouches-Canon, and of the celebrated Madame de Tencin, sister of the archbishop of Lyons. His unnatural parents exposed him, soon after his birth, near the church of St. Jean le Rond, and hence his Christian name. After he became eminent, his father recognised him and gave him a pension. In childhood he displayed great precocity of talent, and in 1730 he entered the College Mazarin, where he had a Jansenist tutor, studied mathematics and philosophy, and wrote a commentary on the Epistle to the Romans. After leaving college he attempted to study medicine, and afterward law; but finding his turn for mathematics all-powerful, he determined to live on his small pension of 1200 francs a year and devote himself to free studies. At twenty-three he was admitted a member of the Academy of Sciences, and in 1741 he published his "Treatise on Dynamics," which was followed by successive publications in mathematical science, all of the first rank, but which do not fall within our province to notice. About 1750 he joined with Diderot in the Encyclopoedie, to which he communicated many articles, and also the preliminary "Discourse." In 1754 he became a member of the French Academy; and in 1759 he published his Elements of Philosophy. After the peace of 1763 D'Alembert was invited by Frederick the Great to fill the office of president of the Academy of Berlin, and the empress of Russia had also solicited him to superintend the education of her children. Having refused, however, both these appointments, he was, in 1772, nominated perpetual secretary to the French Academy, a position in which he wrote seventy eloges of deceased members. In the latter part of his life he was attacked with calculus, and died of that disease in his sixty-sixth year. His miscellaneous writings are collected in OEuvres litteraires, edited by Bastien (Paris, 1805, 18 vols. 8vo; new ed. Paris, 1821, 5 vols. 8vo, the best). As a philosopher, D'Alembert was a disciple of Locke, and carried out his principles to their ultimate conclusion in scepticism and materialism. He never wrote as vulgarly or violently against Christianity as Voltaire, but he was quite as far gone in unbelief. As to the existence of God, he thought the "probabilities" were in favor of Theism; as to Christianity, he thought the "probabilities" were against Revelation. —Hoefer, Biog. Generale, 1, 783; Tennemann, Manual Hist. of Philosophy, § 379.