Descartes Discourse On Method Author:Laurence J. Lafleur, Rene Descartes By calling everything into doubt, Descartes laid the foundations of modern philosophy. He deduced that human beings consist of minds and bodies; that these are totally distinct "substances"; that God exists and that He ensures we can trust the evidence of our senses. Ushering in the "scientific revolution" of Galileo and Newton, Descartes' ideas... more » swept aside ancient and medieval traditions of philosophical methods and investigation.« less