In Mediation's III, Descartes's presents an elaborate argument for the existence of an infinite being, as well as it's thought to be circular. In Descartes argument for an infinite being he uses God to prove the truth of clear and distinct perceptions and also uses clear and distinct perceptions to prove the existence of God. So how can he use clear and distinct perceptions to prove God's existence, if he needs God in order to prove that clear and distinct perceptions to tell us the truth? So I believe that Descartes' is using a circular method to prove his argument that there is a infinite being known as God.
This argument that he gives is the second argument for an infinite being or God. This argument rests on the distinction between two forms of reality. First formal reality, this is the reality that anything has a virtue of existing. Formal reality comes in three types of grades, which are infinite, finite, and mode. God is the only existing thing with infinite formal reality. Substances all have finite formal reality. Finally, modes have modal formal reality, like an idea. To the extent that is considered to an concurrent piece of thought. Ideas, however, also have another kind of reality. This is where we come to the other form or reality. Ideas can be said to have objective reality and like wise to formal reality there is also three grades of objective reality. Exactly mirroring the three grades of formal reality. The amount of objective reality contained in an idea is determined solely on the basis of the amount of formal reality contained in the object represented by the idea. His argument then begins by making the claim that we all have an idea of God as an infinite being. He believes that we cannot fail to have this idea because he thinks it's innate, since our idea of God is of an infinite being, it must have infinite objective reality. Next, Descartes appeals to an innate logical principle that something cannot come from nothing....