D’Alembert wrote many and important works on physics and mathematics.  One of these, ‘Memoir on the General Cause of Winds,’ carried away a prize from the Academy of Sciences of Berlin, in 1746, and its dedication to Frederick II. of Prussia won him the friendship of that monarch.  But his claims to a place in French literature, leaving aside his eulogies on members of the French Academy deceased between 1700 and 1772, are based chiefly on his writings in connection with the ‘Encyclopedie.’  Associated with Diderot in this vast enterprise, he was at first, because of his eminent position in the scientific world, its director and official head.  He contributed a large number of scientific and philosophic articles, and took entire charge of the revising of the mathematical division.  His most noteworthy contribution, however, is the ‘Preliminary Discourse’ prefixed as a general introduction and explanation of the work.  In this he traced with wonderful clearness and logical precision the successive steps of the human mind in its search after knowledge, and basing his conclusion on the historical evolution of the race, he sketched in broad outlines the development of the sciences and arts.  In 1758 he withdrew from the active direction of the ‘Encyclopedie,’ that he might free himself from the annoyance of governmental interference, to which the work was constantly subjected because of the skeptical tendencies it evinced.  But he continued to contribute mathematical articles, with a few on other topics.  One of these, on ‘Geneva,’ involved him in his celebrated dispute with Rousseau and other radicals in regard to Calvinism and the suppression of theatrical performances in the stronghold of Swiss orthodoxy.

His fame was spreading over Europe.  Frederick the Great of Prussia repeatedly offered him the presidency of the Academy of Sciences of Berlin.  But he refused, as he also declined the magnificent offer of Catherine of Russia to become tutor to her son, at a yearly salary of a hundred thousand francs.  Pope Benedict XIV. honored him by recommending him to the membership of the Institute of Bologne; and the high esteem in which he was held in England is shown by the legacy of L200 left him by David Hume.

All these honors and distinctions did not affect the simplicity of his life, for during thirty years he continued to reside in the poor and incommodious quarters of his foster-mother, whom he partly supported out of his small income.  Ill health at last drove him to seek better accommodations.  He had formed a romantic attachment for Mademoiselle de l’Espinasse, and lived with her in the same house for years unscandaled.  Her death in 1776 plunged him into profound grief.  He died nine years later, on the 9th of October, 1783.

His manner was plain and at times almost rude; he had great independence of character, but also much simplicity and benevolence.  With the other French deists, D’Alembert has been attacked for his religious opinions, but with injustice.  He was prudent in the public expression of them, as the time necessitated; but he makes the freest statement of them in his correspondence with Voltaire.  His literary and philosopic works were edited by Bassange (Paris, 1891).  Condorcet, in his ‘Eulogy,’ gives the best account of his life and writings.