Last reviewed: June 2018
French mathematician and philosopher
March 31, 1596
La Haye en Touraine, France
February 11, 1650
René Descartes (day-kahrt), born on March 31, 1596, was the third child of Joachim Descartes, a fairly prosperous member of the minor noblesse de robe (nobility of the robe); he was a counselor in the Parlement (or law court) of Rennes. From 1604 to 1612, René Descartes studied at the College of La Flèche at Anjou, where he received from the Jesuits a firm grounding in every aspect of scholastic philosophy, which he subsequently challenged. After La Flèche, he continued his studies at the University of Poitier, where he sharpened his analytic and geometric methods. His brilliance was quickly recognized, and since he was of very frail health, he was granted relief from morning duties; it was during this time that he acquired his lifelong habit of reflection in bed. It was also during this period that Descartes began to develop his distrust of tradition and authority. René Descartes
In 1612, when he was sixteen, Descartes left school to return home. He completed his preparation for life by studying fencing and horsemanship before he set out for Paris. For two years, he enjoyed the life of the capital and made a number of intellectual friends. Then, in 1614, he abandoned his social life and withdrew for two years of study and contemplation in a house in the suburbs of Paris. In 1617, his privacy having been invaded by friends, Descartes left Paris for the Netherlands, where he enlisted as a volunteer in the army of Prince Maurice of Orange. During a lull in the war, he made the acquaintance of various Dutch intellectuals.
After two years in Holland, Descartes went to Germany in 1619 to enlist in the wars between the Catholic House of Austria and the Protestant German princes. He joined the Catholic army; he was present at the battle of Weisser Berg in 1620. It was during this tour of duty in Germany that Descartes underwent his philosophic “conversion” on the eve of St. Martin’s Day during the winter of 1619. He established in his own mind what were to be the principles of his famous method. He spent the next year serving in Hungary and in the summer of 1621 made a peaceful tour of Eastern Europe. He returned to France in 1622.
After a stay in Paris, Descartes toured Italy and Switzerland and finally returned to Paris in 1625. During the previous several years, he had ceaselessly devoted himself to observation and pure mathematics. In Paris, in the company of his learned friends, he began to devote himself to practical problems of optics and to more abstract and philosophical considerations. Descartes soon left Paris once more for the wars. He participated in the siege of La Rochelle and entered the town with the troops in October of 1628. After this last stint of military service, Descartes decided to devote himself wholly to philosophic pursuits, and in the spring of 1629 he traveled to Holland, where he stayed until 1649, the year before his death. He never married but fathered a child, Francine, whose death in 1640 at the age of five pained him greatly.
Descartes’s philosophical works, especially his Meditations on First Philosophy, established him as the founder of modern analytic philosophy. His declaration Cogito, ergo sum (I think, therefore I am) is the fundamental assumption from which he attempts to prove his mind-body dualism and the existence of God. His method of investigation is scientific, geometrical, and skeptical.
During his years in the Netherlands, Descartes published his great works, most notably Discourse on Method in 1637. He quickly became a controversial figure, and his fame spread throughout Europe. Being both a loyal Catholic and an advanced and revolutionary thinker who refused to accept anything on faith or tradition alone, Descartes avoided open conflict with the Church and the civil authorities. He handily weathered all the storms that arose around his works and around the rapidly spreading Cartesian philosophy, which was influenced by his scientific and mathematical discoveries.
His new mathematics revolutionized the fields of geometry, algebra, and the physical sciences. His Cartesian coordinate system and curves are the foundations of modern analytic geometry. In the sciences, he made a few important contributions to the fields of optics and meteorology, but some of his theories in physics have been completely rejected and are now considered bizarre.
As his fame spread abroad and as his philosophy became fashionable, Descartes was asked by young Queen Christina of Sweden to come to her country to give her instruction in philosophy and to draw up a code of regulations for the establishment of a Swedish Academy of Sciences. He accepted the invitation in 1649. He died of pneumonia in Stockholm on February 11, 1650. He was at first buried in Sweden, but several years later his ashes were returned to France.
Descartes' principal works have remained in print and been translated into French, English, and other major world languages. His correspondence and unedited fragments of his early writings have since been published as well.