In Meditation Three of Descartes' Meditations on First philosophy he makes the argument that an omnipotent and infinite god exists. In this paper I'll reconstruct Descartes argument and evaluate its validity based on the soundness of its premises. Descartes' proof for the existence of god is: 1.) I think, therefore I am. 2.) I can not be mistaken about the ideas that I have. 3.) There must be at least as much formal reality (i.e., object of the idea) in the cause of an idea as there is objective reality (i.e., the idea it's self) of a perfect idea. (Otherwise something would come from noth…