Rene Descartes (March 31, 1596 - Feb 111 650), a philosopher, sportsman, physicist French, nicknamed "Abu philosophy of modern," and many Western theses philosophical that came after him, are the implications of theses, which are still taught today, especially the book ( meditations on first Philosophy -1641 m), which remains a standard text for most of the faculties of philosophy. Descartes also a clear impact in mathematics, he invented a system mathematically named after him, a (Cartesian coordinate system), which form the nucleus for (analytic geometry), was that of the main characters in the history of the scientific revolution. Descartes is the main character of the doctrine of rationality in the 17th century, and was well versed in mathematics as well as philosophy, and made a significant contribution to this science, Descartes is the author of the famous statement:
"I think therefore I am'".