The Ontological Argument for The Existence of God can be traced back to St. Anselm. Although refuted by several philosophers since, such as St. Thomas Aquinas, it was reinstated by Rene Descartes in his “Meditations on First Philosophy”. The Ontological Argument goes as such: The nature of God is that of a supremely perfect being. Existence is necessary to perfection. To deny any perfection of God is to misunderstand the term “God”. It follows then, anyone who can comprehend the idea of God can be led to see that God exists. Descartes Ontological Argument for the existence of God has been accused of circular reasoning, this is often known as the “Cartesian Circle”. However, in this paper, I will outline Descartes’ Ontological Argument for the existence of God and I will show that Descartes is not in fact guilty of circular reasoning.
Descartes’ reasoning is in the form of a reductio ad absurdum. He begins by doubting everything in the first meditation. He supposes that an evil genius has coaxed him into regarding reality as true, when in fact all external things are “bedeviling hoaxes of (his) dreams” (p.16). Descartes then arrives at the famous conclusion of the cogito ergo sum “I think, therefore I am”. Thus he arrives at the conclusion that while he may be able to doubt all other things he cannot doubt that he is a thinking thing: “let anyone who can do so deceive me; so long as I think that I am something, he will never bring about that I am nothing” (p.16). This is the first thing that the Meditator can perceive clearly and distinctly.
The Meditator continues on his journey to remove doubt: “in order to remove even this slight reason for doubt, as soon as the opportunity arises I must examine whether there is a God, and, if there is, whether he can be a deceiver”(p.25). If there is a supreme deceiver, then it can be shown that everything we know is false except “the cogito”. However, if God’s existence is proven, then we know our ideas are not deceptive. God cannot be deceitful for that is not a characteristic of a “supremely perfect being.” In this way Descartes relies on God’s existence to establish clear and distinct perceptions as verified. This is how the “Cartesian Circle” begins to be drawn. Further difficulties come to light, however, if we examine God as self-caused. He infers this by examining the nature of ideas and thoughts. In the following section of this paper I will illustrate how the God’s objective reality leads to the conclusion of his being a first cause.
Descartes distinguishes between different sources of thoughts. The first type are innate ideas which come from within us. The second type are adventitious ideas, these come from our sensory perceptions. The third type are those which we invent. Descartes realizes that all ideas are modes of thought and in this sense they have equal “formal reality”. However, what these thoughts represent are not in any sense equal and therefore different types of thoughts have a different “objective reality”. For example a human being has much more “objective reality” than a lead. Thus it follows that the idea of God has much more objective reality than the idea of a human being. Descartes then points out that all ideas must be born out of something with a greater objective reality than itself. This cannot go on forever though: “although one idea can perhaps issue from another, nevertheless no infinite regress is permitted here; eventually some first idea must be reached whose cause is a sort of archetype…”(p.28). Thus the idea of a first cause, or an “unmoved mover”, comes into effect.
The Meditator establishes that the idea of God is the most clear and distinct idea of all, and that it contains more objective reality than any other idea. He asserts that the idea of God cannot be adventitious or invented, and that therefore, it must be innate. The meditator must have been created by God with the idea of God in him. Descartes writes that it is “the mark of the craftsman impressed upon his work…”(p.28). This is made so, according to the Meditator, since we have already established that what is more perfect cannot come into being out of what is less perfect. Descartes does not just immediately accept this, however.
What if, asks the Meditator, the idea of God did in fact come from within me? What if I am a perfect being who can conceive an idea with the colossal objective reality that is God and I have just not yet reached my full potential? The Meditator addresses these doubts by showing that potentiality contradicts perfection. Perfection indicates something that is actual and complete. Therefore, the Meditator is not “a potentially perfect being” because this leads us to a contradiction. The idea of God must be caused by something that is infinite and actual…not something potential. Only God is such a being. Not only is God the original cause of all ideas, but God is the original cause of God himself.
Despite the prima facie soundness of Descartes’ argument, this proof of God runs the risk of circular reasoning. Descartes claims that whatever one clearly and distinctly perceives must be true because God is not a deceiver. He claims also that God must exist because we can clearly and distinctly perceive the conception of God. In other words, if God is the cause of all ideas, and God is not a deceitful being because he is perfect, than all ideas must be true. Therefore if we have a clear and distinct idea of God his existence must be, since God would not deceive us into thinking that there is a God at all. This appears to be a very circular argument indeed.
Antoine Arnauld is among the first scholars to point out the fault in Descartes’ reasoning. In the “Fourth Set of Objections,” he states:
“I have one further worry, namely how the author avoids reasoning in a circle when he says that we are sure that what we clearly and distinctly perceive is true only because God exists. But we can be sure that God exists only because we clearly and distinctly perceive this. Hence, before we can be sure that God exists, we ought to be able to be sure that whatever we perceive clearly and evidently is true.” However we may question as to whether this is the correct reading of Descartes. Several scholars believe that it is error-some and that the correct reading of Descartes does not wind him up in the Cartesian circle.
Descartes himself replies to Arnauld’s critique and says that he makes “a distinction between what we in fact perceive clearly and what we remember having perceived on a previous occasion.” This forces one to re-evaluate Descartes’ epistemology. Perhaps we ought to read The Meditations in a way which God is not the confirmation of clear and distinct ideas, but rather a safeguard against doubt. Thus the argument would look more like this: We know God exists because we clearly and distinctly perceive the idea of God. And we can re-affirm our clear and distinct ideas in retrospect once we prove that God exists. Therefore instead of reading the meditations as God being the source of all knowledge, we ought to read it as clear and distinct perceptions as the source of knowledge. This reformulation of Descartes’ epistemology offers a buffer against The Cartesian Circle argument.
In the preceding paper I have outlined Descartes’ Ontological Argument for the existence of God. By doubting everything, Descartes arrives at the “Cogito”. He then establishes what can be considered as “clear and distinct ideas”. He shows that God is the most clear and distinct idea of all as He has the greatest objective reality. Therefore to have an idea of God as perfection it must be true that he exists for perfection is a characteristic of existence. I have pointed out critiques of Descartes’ reasoning and provided a defense for Descartes. Those readers who accuse him of circular reasoning may perhaps need to read Descartes Meditations under a new light.
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Cambridge University Press, 1984. pp.142-246. Print.
 Descartes, Rene. The Philosophical Writings of Descartes. 2. Great Britian: Cambridge University Press, 1984. 142. Print  Descartes, Rene. The Philosophical Writings of Descartes. 2. Great Britian: Cambridge University Press, 1984. 246. Print.