>>14293187It's in the third meditation.
In the first proof, Descartes argues that, by evidence, he is an imperfect being who has an objective reality including the notion that perfection exists and therefore has a distinct idea of a perfect being (God, for example). Further, Descartes realizes that he is less formally real than the objective reality of perfection and therefore there has to be a perfect being existing formally from whom his innate idea of a perfect being derives wherein he could have created the ideas of all substances, but not the one of God.
The second proof then goes on to question who it is then that keeps him — having an idea of a perfect being — in existence, eliminating the possibility that he himself would be able to do. He proves this by saying that he would owe it to himself, if he were his own existence maker, to have given himself all sorts of perfections. The very fact that he is not perfect means he would not bear his own existence. Similarly, his parents, who are also imperfect beings, could not be the cause of his existence since they could not have created the idea of perfection within him. That leaves only a perfect being, God, that would have had to exist to create and be constantly recreating him.
