Descartes dreamed up a new philosophy in a stove-heated room one winter night
On a freezing November night in 1619, a young soldier named René Descartes shut himself in a room warmed by a stove and had three vivid dreams. He emerged convinced that mathematics could rebuild philosophy from the ground up. The result gave us analytic geometry, Cartesian coordinates and I think, therefore I am.
Descartes was born on 31 March 1596 in La Haye en Touraine, a town now named after him. His mother died when he was one, and he was raised by his grandmother and great-uncle. Sickly, he started late at the Jesuit college of La Flèche, where he met mathematics and physics, then took a law degree at Poitiers in 1616 to please his father. In 1618 he enlisted as a mercenary in the Dutch army of Maurice of Nassau, studying military engineering and befriending the scholar Isaac Beeckman.
The dream night of 10 to 11 November 1619 came while he was serving the Duke of Bavaria at Neuburg on the Danube; one theory suggests the loud noise of his second dream was exploding head syndrome. He left the army in 1620, sold his property for bonds that kept him comfortable for life, and after Cardinal Bérulle urged him to write beyond the Inquisition's reach, settled in the Dutch Republic, where he wrote all his major works. With the servant Helena Jans van der Strom he had a daughter, Francine, who died of scarlet fever at five; he wept openly, rejecting the idea that tears unman a man.
Galileo's condemnation in 1633 made him shelve his Treatise on the World. Instead, in 1637, he published the Discourse on the Method, introducing essays on optics, weather and geometry. Its method was radical doubt: discard every belief that can be doubted, then rebuild on what survives, like clearing soil before laying foundations. La Géométrie joined algebra to geometry, the step that paved the way for calculus. The Meditations of 1641 and the Principles of 1644 followed, and a long correspondence with Princess Elisabeth of Bohemia produced The Passions of the Soul.
Condemned at Utrecht in 1643, Cartesian ideas still made him famous. In 1649 Queen Christina invited him to Stockholm, where he took early barometer readings to test weather forecasting. Lessons at 5 a.m. in a cold castle went badly; they disliked each other. He died on 11 February 1650, probably of pneumonia, and his skull's whereabouts remain uncertain.
Source: René Descartes
