A French mathematician and philosopher, born in Provence; declared against scholastic methods out of deference to the empirical; controverted the metaphysics of Descartes; became the head of a school opposed to him; adopted the philosophy of Epicurus and contributed to the science of astronomy, and was the friend of Kepler, Galileo, and Hobbes; was a great admirer of Bayle, the head of his school, a school of Pyrrhonists, tending to materialism (1592-1655).