Gassendi, Pierre (1592-1655), French philosopher and savant, born in Champtercier, near Digne, and educated at Digne and at the universities of Aix-en-Provence and Avignon.
In 1617 he was appointed professor of philosophy at the University of Aix-en-Provence. During the next years he taught, traveled to Flanders and Holland, and worked on studies in science and philosophy. In 1634 he was appointed provost of the cathedral at Digne, and in 1645 he became professor of mathematics at the Collège Royal in Paris. He retired in 1648. As a philosopher he first became known through his attacks on the theories of Aristotle; he also participated in a controversy with the French philosopher René Descartes over the nature of matter.
In 1647 his De vita et Moribus Epicuri (On the Life and Character of Epicurus) was published, followed two years later by two more works on the ancient Greek philosopher Epicurus. Gassendi's theories are considered to have prepared the way for modern empirical methods, anticipating those of the English philosopher John Locke and the French philosopher Étienne Bonnot de Condillac; he was chiefly responsible for reviving interest in the philosophy of Epicureanism in modern times. His scientific work was mainly in the fields of astronomy and cartography.