Encyclopedia of Philosophy: THE LIFE OF DESCARTES

Among those who fought on the Catholic side in the Thirty Years War was the most important philosopher of the seventeenth century, René Descartes. Descartes was born in 1596, in a village which is now called La-Haye-Descartes. He was educated by the Jesuits and remained a Catholic throughout his life; but he chose to spend most of his adult life in Protestant Holland. He was a man of the world, a gentleman of leisure living on his fortune; he never lectured in a university and commonly wrote for the general reader. His most famous work, the Discourse on Method, was written not in academic Latin, but in good plain French, so that it could be understood, as he put it, ‘even by women'.  While serving in the Emperor's army, Descartes acquired a conviction of his mission as a philosopher. On a winter's day in 1619 he conceived the idea of undertaking, single-handed, a reform of human learning that would display all disciplines as branches of a single wonderful science. When he went to sleep, full of ardour for his project, he had three dreams that he regarded as prophetic signs of divine vocation.