DESCARTES, RENE (da-kart'), a French philosopher and mathematician. with whom the modern or new philoso phy is often considered as beginning; born in La Haye, in Touraine, March 31, 1596. He was educated at the Jesuit College of La Fleche, where he showed great talent. He entered the military profession and served in Holland and in Bavaria. In 1621 he left the army, and after a variety of travels finally settled in Holland, and devoted himself to phil osophical inquiries. Descartes, seeing the errors and inconsistencies in which other philosophers had involved them selves, determined to build up a system anew for himself, and resolving to ac cept as true only what could stand the test of reason. There was one thing that he could not doubt or divest himself of the belief of, and that was the exist ence of himself as a thinking being, and this ultimate certainty he expressed in the celebrated phrase, "Cogito, ergo sum" (I think, therefore I am). Start ing from this point, Descartes found the same kind of certainty in such propo sitions as these: that the thinking being or soul differs from the body (whose existence consists in space and exten sion) by its simplicity and immateriality and by the freedom that pertains to it; that every perception of the scul is not dis tinct; that it is so far an imperfect finite being; that this imperfection of its own leads it to the idea of an absolutely per fect being; and from this last idea he deduces all further knowledge of the truth. Descartes also contributed great
ly to the advancement of mathematics and physics. His system of the universe at tracted great attention in his time, though long since exploded. His works effected a great revolution in the princi ples and methods of philo'ophizing. In 1647 the French court granted him a pension and two years later, on the in vitation of Christina of Sweden, he went to Stockholm, where he died, Feb. 11, 1650.