In the Third Meditation, Descartes establishes evidence for the existence of God. He begins by laying the foundation for what he claims to know and then offers an explanation of why he previously had accepted various ideas but was no longer sure. Before arriving at the concept of God, Descartes classifies ideas and the possible sources from which they originate. He then distinguishes between the different degrees of reality that an idea can possess, as well as the cause of an idea. Descartes proceeds to investigate the idea of ​​an infinite being, or God, and how he came to acquire that idea with a more objective reality than he himself has. Excluding the possibility that this idea is invented or adventitious, Descartes concludes that the idea must be innate. Therefore, God necessarily exists and is responsible for his perception of a thing beyond a finite being. Descartes claims to be certain that he is a thinking thing. His reasoning, however, appears to be a circular argument. Descartes knows he is a thinking thing because “in this first moment of knowledge there is nothing other than a certain clear and distinct perception of what I affirm” (Descartes, 24). He concludes: "everything that I perceive very clearly and distinctly is true" (Descartes, 24). Descartes could know that what he perceives clearly and distinctly is true only if he could be certain that it was a thinking thing. Throughout this demonstration, Descartes tries to use the existence of God as a way to affirm what he perceives clearly and distinctly. However, he is also trying to prove the existence of God by arguing that the idea of ​​God is a clear and distinct perception. Without investigating the existence of God, “it seems that I am never capable of being completely… middle of paper… that God also exists” (Descartes, 34). Descartes' proof of God's existence comes from his claim that something cannot come from nothing. Since God is a perfect being, the idea of ​​God can be found by exploring different notions of world or imagination ideas; since the world contains material objects, perfection does not exist. Descartes emphasizes the idea that his idea of ​​the existence of God does not originate from his senses, rather than having created the idea himself, he states that God himself imprinted it "So the only option left is that this idea be innate in me just as the idea of ​​myself is innate in me" (Descartes, 34). innate ideas are a truth.