History of Western Philosophy Modern Period

He explained that the fact that one is thinking a particular idea means that there is an equal or greater thing being represented. For instance, if a person is thinking of a chair, the fact that he has an idea of what a chair is means that there is an actual chair equal to what he is picturing in his head or that there is an even greater reality of a chair that the person cannot perceive completely by just using his senses. Descartes then concluded that “it will necessarily follow that I am not alone in the world, but that some other thing which is the cause of this idea also exists” (7:42). Hence, if he has an idea of the existence of God, then there must be an equal or higher reality which causes him to think about it—and that is none other than God Himself, “a substance that is infinite, independent, supremely intelligent, supremely powerful, and which created both myself and everything else (if anything else there be) that exists,” and is supremely good (7:45).
Descartes’ second proof is derived from this: that God is all-powerful and all-good. So, if by any chance what he clearly and distinctly perceives, which leads to ideas and knowledge, is false, there is a way to correct it by using our minds and meditating to get clearer and more distinct perceptions. However, if the clearest and most distinct perception of all—that of the idea of God—is false, then that cannot be corrected. It can then be concluded that God is a deceiver because He chose to deceive the meditator. But it has already been established that God is all-good. So, if God is all-good, then it is not possible for God to be a deceiver.
Here lies the Cartesian Circle or the circular argument presented by Descartes in proving the existence of God: in order to prove God’s existence, there must be a clear and distinct perception. However, the veracity of this clear and distinct