Descartes' Third Meditation

Descartes' Third Meditation

Descartes' argument for God's existence in the third meditation is more like the ontological then the cosmological argument. His meditation is about what is real and how to prove it is. He mainly wants to prove the existence of God, which would prove all other things to be true. Anselm's ontological argument is that the greatest thing that can be thought of is the existence of God. St. Aquinas' cosmological argument is that God was the first to exist and he created everything the way it is today.

Descartes' Third Meditation is all of his ideas and thoughts on what is considered to be real. He is doubtful of bodily things but is certain that he exists and that he is a thinking thing that doubts, understands, imagines, and senses. Descartes says that you can only be certain of something if it is clear and has distinct perceptions; this is known as natural light. At first he thought he was certain on all sorts of different things. Then he realized that he hasn't been perceiving things as themselves, but only the ideas or thoughts of those things. He's also not certain about anything because he thinks that God could be deceiving him and to assure this isn't happening he must understand God (Descartes, 24-36).

He starts off by classifying his ideas into different categories. The first category is made up of simply ideas, such as images and pictures of his thoughts. Next category consists of emotions, violations, and judgments towards an object of thought. Through this he reasons that he cannot be mistaken with regard to ideas on their own, nor with regard to volitions or emotions. He can only make mistakes towards these ideas through his judgment of them (Descartes, 24-36).

Descartes wants to escape the problem involving clear and distinct perceptions by relying on God's existence to make them true. The problem is that he wants to prove God's existence by claming it as a clear and distinct perception; this is known as the Cartesian Circle. Next he talks about how all ideas have a formal and objective reality. All ideas are modes of thought, so in that sense they are all equal. All ideas have some formal reality, the actual being of a thing as the thing it is. However, their objective reality, ideas in their representative form, differs greatly. Another step leading to God's existence is the idea that no effect can have a greater amount of reality than its cause. Meaning that nothing coming into existence can be greater then what it came from. For example you can't chip off a piece of rock that is bigger then the piece you chipped it from, can only have a smaller rock or one of equal size. Since everything came from God and nothing can be greater then what it came from, God is the greatest idea possible. From the reasoning of the Wax Argument, Descartes concludes that he can only clearly and distinctly perceive properties like size, extension, shape, motion, duration, number, and substance when examining bodily things (Descartes, 24-36).

Once Descartes considered God as a substance that is infinite, eternal, independent, supremely intelligent, supremely powerful, and which created both him and everything else he realized that the idea of God must have far more objective reality than he has formal reality. Although he can doubt the existence of other things, he cannot doubt the existence of God, since he has such a clear and distinct perception of God's existence. The idea of God has infinite objective reality, and is therefore more likely to be true than any other idea. Descartes then begins to think of where the idea of God came from. He begins to compare how God came about to how he came about. However he soon realizes that the idea of God can not come from a finite being. This is part of the idea that you can't get something greater out of something of lesser value. After concluding that God exist he wonders how the idea of God came to him and all other beings. He says the idea cannot be adventitious nor could it have been invented by himself. Thus, the idea must be innate, and that he was created by God with the idea of God already in him. Finally Descartes now clearly and distinctly perceives that God is not a deceiver, since all deception relies on some defect or other, and God is perfect with no defects (Descartes, 24-36).

Anselm's ontological argument for God's existence is somewhat similar to Descartes' argument. The first part of Anselm's argument is that the greatest possible attribute God can have is existence. He states that God is the greatest thing that can be conceived, God is "something greater which cannot be thought." The next part of Anselm's argument is that it is illogical to consider God as not existing. If God does not exist then there must be something greater than