D'ALEMBERT, JEAN-BAPTISTE LE ROND. – Philosopher and mathematician, born in Paris on 16 November 1717, died there on 29 October 1783. A member of the Academy of Sciences and of the Académie Française, he is remembered both for fundamental works on integral calculus, mechanics, etc., and for that powerful publishing enterprise, the Encyclopédie (for D'A.’s philosophical system, expressed therein, see the treatment contained in the entry ENCICLOPEDIA).
His collaboration in the Encyclopédie, his correspondence with Voltaire and Frederick II, and his minor works all clarify his profile as a straightforward and convinced, but cold and translucent, follower of utilitarian rationalism. In the course of his spiritual development, he eventually came to conceive of a natural morality elevated to the rank of a science, indeed as the matrix of all the sciences, and to delineate revealed religion as a « supplement » to natural knowledge. His « positivism » arose from the attempt to confine the Enlightenment within scientific schemes (F. Venturi, op. cit., p. 84). Among his minor works, Sur la destruction des Jésuites en France (s. l. 1765) should be mentioned; in it he constructs the myth of the « philosophy » that thwarted the Jesuits’ ambitious attempt to dominate the world. As for the Jansenists, he deplores their pointless disputes. Of great interest are D'A.’s various eulogies: of Bossuet, Massillon, Montesquieu, and Fénelon; particularly characteristic is the eulogy of Fénelon for the way it presses the thesis: Fénelon is portrayed as a friend of morality more than of religion itself (v. , for example, D'A., Oeuvres, II, 1, Paris 1821, p. 491).