René Descartes

René Descartes (1596–1650) was a French philosopher and mathematician, born at La Haye, whose method of systematic doubt marks the beginning of modern philosophy. Educated by the Jesuits at La Flèche, he joined the Dutch army at Breda in 1618. In November 1619, in a heated room at Neuburg, three dreams gave him analytic geometry and the idea of applying mathematics to philosophy.

From 1628 he lived in the Dutch Republic. After Galileo's condemnation in 1633 he abandoned his Treatise on the World, and in 1637 published the Discourse on the Method, whose La Géométrie joined algebra to geometry and which set out cogito, ergo sum. The Meditations followed in 1641.

His young daughter Francine died in 1640, and he wept openly. In 1649 Queen Christina of Sweden called him to Stockholm, where early-morning lessons in a cold castle gave him pneumonia; he died on 11 February 1650.