Descartes attempted to apply the rational inductive methods of science, and particularly of mathematics, to philosophy. Before his time, philosophy had been dominated by the method of Scholasticism, which was entirely based on comparing and contrasting the views of recognized authorities. Rejecting this method, Descartes stated, "In our search for the direct road to truth, we should busy ourselves with no object about which we cannot attain a certitude equal to that of the demonstration of arithmetic and geometry." He therefore determined to hold nothing true until he had established grounds for believing it true. The single sure fact from which his investigations began was expressed by him in the famous words Cogito, ergo sum,"I think, therefore I am." From this postulate that a clear consciousness of his thinking proved his own existence, he argued the existence of God. God, according to Descartes's philosophy, created two classes of substance that make up the whole of reality. One class was thinking substances, or minds, and the other was extended substances, or bodies. I really love Philosphy its really develops your mind, and makes you think twice about certain topics.Please Register or Log in to view the hidden image!