Descartes\' Fifth Meditation and God\'s

Descartes' Fifth Meditation and God's Existence

In the Fifth Meditation, Descartes turns to consider what kind of certainty he can attain regarding ideas of objects that may exist materially outside the mind. He finds within himself "countless ideas of things which even though they may not exist anywhere outside me still . . . have their own true and immutable natures" (at VII: 64). This leads him to a contemplation of the triangle. The idea of a triangle as an object of thought is an analogy used in the meditation to support an ontological proof for God's existence. This paper will discuss this argument critically and present counterarguments that suggest that Descartes' ontological position fails. He shows only that an idea of God is possible, not that God actually exists.

Descartes sees that the triangle has an essence that is immutable and eternal, whether or not it exists outside his thought. A triangle and its properties -- for example, its shape with three sides whose interior angles necessarily add up to 180 degrees -- do not depend on a mind for their essence. He can clearly and distinctly perceive a triangle even without having had sense experience of it. Therefore, it is certainly true since clear and distinct perception is his definition of truth. This does not, however, solve the problem of whether the triangle actually exists outside the mind (realism) or is just purely inside the mind (psychologism). It simply means that a triangle with its essential properties is clearly and distinctly conceivable.

When he applies this same reasoning to the idea of God, he finds that he has the idea of a supremely perfect being in his mind already, clearly and distinctly, as a mental perception. This clear and distinct idea he has of this object (God) is the true nature or essence of God. It includes that God is singular, always exists, and, most significantly, necessarily exists outside the mind. He asserts realism. Descartes makes this argument because "it is quite evident that existence can no more be separated from the essence of God than the fact that its three angles equal two right angles can be separated from the essence of a triangle" (VII: 66). In his view, it is contradictory to think of a supremely perfect being that lacked existence. In other words, one cannot think of God as perfect without supposing God's existence.

If someone objected that God does not necessarily possess perfection -- pointing for example to the Greek gods who were almighty but not perfect -- Descartes would reply that the idea in him (Descartes) is of a perfect God, not an imperfect one. Descartes cannot conceive of God without God possessing all perfections (singularity, eternity, and real existence). Descartes' response does not answer the objection. All it does is reaffirm the idea that he insists on holding of God. The word "God" does not necessarily imply a supremely perfect being.

For another thing, existence is not necessarily a perfection. It is merely the precondition for the presence of perfections. If God is actually real, he would need existence. But that reality is exactly what is under dispute. There is no reason based on the idea itself to assume that real existence is implied in the idea. Necessary existence need not be implied by any concept. Descartes wants to avoid saying that the idea of God comes from experience. But how could one know that the true and immutable nature of a being is to exist purely on the basis of an idea? In fact, this argument works better for a triangle, since its essence is implied in the definition. It does not hold, however, for God, whose definition is contestable. Descartes would resort to saying that any other concept of God would be self-contradictory. This is not necessarily true. One's definition of God's attributes does not make it the case.

Descartes recognizes the major objection to this position: that his thinking the idea of God does not make God exist. What a person thinks does not create the thing. He says, "For my thought does not impose any necessity on things; and just as I may imagine a winged horse even though no horse has wings, so I may be able to attach existence to God even though no God exists" (VII: 66). But his response is flawed. He flips the priority around: it is not that his thinking determines God's existence, but that God's existence necessarily determines his thinking. He is "not free to think of God without existence" (VII: 67), even though he could with a winged horse. This argument presupposes the existence of a perfect God, and does not imply it. It is not the result of his argument, but its assumption. To believe that one's thinking is determined by the thing in reality is to assume its prior existence, not to prove it before existence. All it does is replicate the truth of his idea. It proves that he has a particular idea of the essence of God, not that a perfect God with existence exists outside his mind. His flaw is to mistake his idea for reality itself, when all it does is prove the reality of the idea.

He raises another question regarding memory: if one is unaware of God, one may doubt God. Here another important point arises, which he does not consider: one might never actually have an idea of God. Descartes proof for God's existence relies on necessarily having an idea of God. But what if one never had the idea in the first place? Or if one's idea of God was not clear, but indistinct? Descartes ontological proof does not address this issue. It merely presumes that any natural person will necessarily have an idea of God.