Descartes, René

Descartes, René (1596–1650), French philosopher and mathematician. His main works are: Discours de la méthode (printed as an introduction to the conclusions of his scientific research in 1637), Méditations philosophiques (originally published in Latin in 1641), Principia philosophiae (1644), and Traité des passions de l'âme (1649). They have exerted a unique influence on European thought. Philosophically his starting point is the problem of certainty posed by Montaigne's radical sceptism. Rejecting the accumulated preconceptions of the past (‘systematic doubt’), he proposes to reconstruct the whole of philosophy on the basis of a few self-evident intuitions, such as the existence of the self in consciousness (‘cogito ergo sum’) and of elementary logical truths, such as the principle of non-contradiction. From these premisses he attempts to deduce the existence of God as guarantor of the reliability of the perceptible world, and thus of its susceptibility to scientific analysis. As a mathematician he considered mathematical reasoning to be applicable to the whole of science. His reduction of matter to the quantifiable has remained fundamental to science. In epistemology and ethics, his rigorous dualism (between mind and body) has been immensely influential. He is generally regarded as the founder of modern philosophy.