Pierre Gassendi

Pierre Gassendi (1592 to 1655) was a French philosopher, Catholic priest and scientific observer from Champtercier in Provence who rebuilt ancient atomism into a modern empiricism. He held a professorship at Aix, rose from canon to provost of the cathedral chapter at Digne, and in his later years worked between Provence and Paris, where he joined the circle around Marin Mersenne and became professor of mathematics at the Collège Royal. He broke with Aristotelian teaching in his Exercitationes Paradoxicae of 1624, objected to Descartes's Meditations, and revived the philosophy of Epicurus, recasting it so it could stand beside Church doctrine. For Gassendi all knowledge of the natural world is limited to what the senses report, so metaphysics is speculation that must answer to observation. He also observed the transit of Mercury in 1631.