( 1596 - 1650 )
Cogito ergo sum "I think, therefore I am."
Regarded as the founder of modern philosophy, René Descartes applied the newly developed scientific method to philosophy. He conceived of a new approach which could bring together all of human knowledge and make philosophy a universal science based in reason. Descartes' rationalism was applied not only to the nature of the physical universe but also to the nature of the human soul and to the existence of God.
Descartes made a clear distinction between Body, which is composed of the same sort of atomic matter as all else on earth, and Mind, which has no physical substance. Descartes conceived of these as as two separate but interacting entities. It is Mind that distinguishes man as a rational being from all other life on earth. Through a process of reasoning which involved a systematic stripping away of all doubts, Descartes proves to himself and others that he must exist because he is a rational being - "I think, therefore I am." He uses the same thought processes to prove the existence of God.
Descartes' God presides over a mechanical universe which he has created and organised according to strict scientific laws. It is the task of science to find out what these laws are.