In his Meditation Descartes provides two arguments for the existence of God. One argument is a causal argument while the other one is an ontological argument for the existence of God. The ontological argument for the existence of God that he proposed in fifth Meditation is a straightforward one. Descartes claims that our idea of God is the idea of a perfect being. Perfection entails lack of nothing so, if something is perfect, then it must exist because something that does not exist cannot be perfect. But, God is perfect; therefore, he has to exist. The perfection of God demands that He exist as it is perfect to exist than not exist. In the words of Descartes, “There is not any less repugnance to our conceiving a God (that is, a Being supremely perfect) to whom existence is lacking (that is to say, to whom a certain perfection is lacking), than to conceive of a mountain which has no valley.” (Descartes, Meditations on First Philosophy) So, in Descartes view God’s existence is linked to God’s essence as the idea of a mountain is linked to the idea of a valley, one cannot be without the other. Similarly, one cannot, simultaneously, believes in the idea of a perfect God and then deny His existence. In simple words, God cannot be perfect without the existence, but God is perfect, therefore, God exists.
The second argument, the so-called causal argument, is present in the third meditation. This argument deals with the clear and distinct ideas and with the cause of ideas. Descartes contends that ideas have an objective reality that is our ideas represent objects that are the cause of those ideas. He observes in third Meditation, “Of my thoughts some are, so to speak, images of the things, and to these alone is the title “idea” properly applied; examples are my thought of a man or of a chimera, of heaven, of an angel, or [even] of God.” (Descartes, Meditations on First Philosophy) Descartes causal argument regarding the existence of God runs as follow. We have an innate idea of a perfect Being, but ideas cannot be more perfect than the objects causing them. We are capable of conceiving the idea of a perfect Being and the idea of a perfect Being can only be caused by a perfect Being. However, we human beings are not perfect so we cannot create this idea of a perfect Being. There must be something formally perfect to cause the idea of a perfect God. Only God is a formally perfect thing. But, to create the idea of a perfect being in our mind God has to exist. As the idea of a perfect being is present in our mind, therefore, God exists. The causal claim of God’s existences hinges upon Descartes following basic assumption, “There is at least as much reality in the efficient and total cause as in the effect of that cause. And, “What is more perfect cannot arise from what is less perfect.” (Descartes, Meditations and Other Metaphysical Writings)
The main problem, in Descartes both arguments, is that he claims that we all have an innate idea of a perfect God. The claim that we all possess the idea of a perfect being that we cannot help, but to think about a perfect being is not a very persuasive one. It is not very clear that the idea of a perfect being is an innate one. It is certainly possible that instead of having the idea of a perfect being we might have an idea of an approximate perfect being. In that case, the idea would not be completely perfect, and hence, the existence of a perfect being would not be required to create that idea. Likewise, Cartesian cycle is a very strong objection against Descartes arguments of God’s existence. According to this objection, Descartes arguments are based upon circular reasoning as in the beginning of the third meditation Descartes proves the existence of clear and distinct ideas on the basis of God’s existence, and then he uses clear and distinct ideas to prove the existence of God. The argument does look like a circular one.
Descartes argument of God’s existence leads him to believe that God is perfect and a perfect Being does not deceive. This conclusion begs the question that if God does not deceive us, and if He has granted us with faculties perfectly capable of discerning the truth why we so often make mistakes? What, then, is the reason of our errors? The issue, Descartes believes, lies in our faculty of judgment. Descartes considers that our faculty of judgment arises from two distinct abilities namely, understanding and will. He further claims that neither our understanding nor our will alone can lead us to errors, but it is the combination of will and understanding that make us err. Understanding is our ability to form ideas and perception about the world. The faculty of understanding is constrained and limited because we are finite beings and can form only limited number of ideas in our finite existence. While the will, notwithstanding, is as impeccable as it could be. God has given us the faculty to judge between truth and falsehood and we are free to give our judgments on all the matters. But, our understanding of the world is limited we do not know about all the things. We make mistakes when we try to give judgments on the matters which are beyond our understanding or the things about which we have not acquired enough knowledge. When we exceed from our limits of understanding and utilize our faculty of will without clear understanding, we make mistakes and establish false beliefs. Hence, Descartes concludes, blunders of judgment happen when the will consents to things which are beyond the extent of the comprehension. (Descartes: God and Human Nature)
Then again, there still remains the inquiry of why God does not confine the will, make the comprehension all the more effective, or even provide us an inclination to withhold judgment from indistinct observations. Once more, Descartes finishes the debate without a logical explanation by simply saying, God has great explanations behind making people the way they are despite the fact that we may not comprehend them. Besides, since our will is sufficiently immaculate to withhold judgment from things which we don't comprehend, we can't accuse God of the slip-ups we make. In the light of the above discussion, I would be inclined to conclude that although Descartes tries to give an account of our errors, the logical reasoning of the argument is not a very persuasive one. Descartes account leaves us with as many philosophical problems as it solves.
Descartes, Rene. Meditations and Other Metaphysical Writings. Penguin Classics, 1999.
—. Meditations on First Philosophy. 1641.
"Descartes: God and Human Nature." n.d. Philosophypages.com. Web. 22 Nov. 2014.