CROUSAZ, Jean Pierre de (1663-1748), professor of philosophy and mathematics, was born at Lausanne, of a noble Protestant family. He was destined by his father for the profession , of arms, but his tastes were literary. Instead of joining the army, he went to study at Geneva, especially devoting himself to mathematics and the Cartesian philosophy, which he adopted. After some time spent in travelling, he returned to his native place, where he was successively appointed pastor, professor of philosophy, and rector of the academy. In 1724 he was called to Groningen to teach mathematics, and appointed governor to the young Prince Frederick of Hesse-Cassel. The king of Sweden also conferred upon him the title of counsellor of embassies.

His works are exceedingly voluminous, but seldom rise above mediocrity. The most important are Système des Reflexions qui peuvent contribuer à la netteté et à l'étendue de nos Connaissances, ou nouvel Essai deLogique; Traitédu Beau, in which he maintains the view that beauty entirely consists of unity in diversity; De l'Edu∙ cation des Enfans; Examen du Traité de la Liberte de Penser d'Antoine Collins; Géométrie des Lignes et des Surfaces rectilignes et circulaires; Examen du Pyrrhonisme ancien et moderne, an attack chiefly on Bayle; Oeuvres diverses; Traité del' Esprit Humain; Réflexions sur la belle IVolfienne; and an attack on the Leibnitzian theory of Pope's Essay on Man.