D'ALEMBERT, Jean-Baptiste le Rond. — Philosopher and mathematician, b. in Paris on 16 Nov. 1717, d. there on 29 Oct. 1783. Member of the Academy of Sciences and of the French Academy, he is associated both with fundamental works on integral calculus and mechanics, and with that monumental editorial undertaking which was the Encyclopédie (for D’A.’s philosophical system as expressed therein, see the treatment in the article on ENCYCLOPEDIA).
Both through his collaboration on the Encyclopédie and through his correspondence with Voltaire and Frederick II, and also in his minor works, his figure emerges as that of a sincere and convinced, yet cool and transparent, follower of utilitarian rationalism. In the course of his spiritual development he reached a point at which he conceived a natural morality elevated to the rank of a science, indeed as the matrix of all sciences, and sketched revealed religion as a mere “supplement” to natural knowledge. His “positivism” arose from an attempt to confine the Enlightenment within scientific frameworks (F. Venturi, op. cit., p. 84). Among his minor works should be noted Sur la destruction des jésuites en France (n.p. 1765), in which he constructs the myth of “philosophy” as having dispelled the ambitious designs of the Jesuits to dominate the world. As for the Jansenists, he deplored their futile disputes. Of great interest are his various eulogies: on Bossuet, Massillon, Montesquieu, and Fénelon; especially characteristic is the eulogy of Fénelon, in which the thesis is forced: Fénelon is portrayed as more devoted to morality than to religion itself (cf., e.g., D’A., Oeuvres, II, 1, Paris 1821, p. 491).