Criticism of the Ontological Argument for God's Existance

As one of the weakest arguments for the existence of God, I thought it would be a good place to start. As stated before, the ontological argument basically says that if we have a concept or definition of God, then God must exist. This is true, Anselm and Descartes would argue, because God's basic traits (the greatest thing imaginable and that thing that cannot deceive) demand that we acknowledge the fact that God exists.

A number of very solid thinkers have pointed out several rather obvious problems with the ontological argument, namely, we can have all sorts of images in our head that do not, nor have ever corresponded with reality. For example, the contemporary of Anselm, Gaunilo asks "Now could it not with equal justice be said that I have in my understanding all manner of unreal objects, having absolutely no existence in themselves, because I understand things if one speaks of them, whatever they may be?" He further accuse Anselm of confusing the mental formation of an object with actually discovering whether it even is real. Gaunilo asks us to image the greatest possible island and compare it with the concept of a being that which nothing greater can be imagined. (What properties of this island would make it the best island after all?) If, according to Gaunilo, this argument works for the existence of God it should work for the existence of the perfect island, which, on the face of it, seems silly. Just because we can image the greatest possible island, for example, does that mean it exists? Does Santa Claus exist because every December I am bombarded with mental constructs of the Jolly ol' Elf?

A more coherent and real critique of the ontological argument comes from Kant. Without going into too much detail (and the much dreaded re-reading of Critique of Pure Reason), Kant says that existence is not a property of objects. Existence is only a property of a concept. Whether the ideas that make up the concept of God (which may or may not manifest themselves in reality) is yet to be determined. Existence (being) is not something we can safely call an attribute. Existence is not a predicate. Consider the following attributes of God:

• God is good
• God is all powerful
• God is the creator of the universe

Each of these predicates (good, all-powerful, creator of the universe) is a real property of God. What Kant is saying, though, is that the ontological argument makes a fundamental mistake by neglecting to have a real predicate. In other words, the ontological argument simply states "God is" (simply because I can construct the concept of God in my imagination). This statement is actually contentless because existence is not a true property of God (or anything else for that matter). Therefore, the ontological argument fails. What Kant seems to be saying, and I think I agree, the ontological argument is really saying: God is, therefore God is. To which, Kant would ask: have you no other premises? (And, after showing that the ontological argument lacks the basic structure of a real agrument, God is what?)

I personally find Gaunilo and Kant persuasive, especially in the absence of other empirical or rational arguments for God's existence. There is just something wrong with the basic ontological argument; I feel like someone is playing some kind of word-game with me. But I cannot exactly pinpoint the problem any better than Hume, Aquinas, Gaunilo, or Kant. In essence, as a metaphysical realist myself, I reject the idea that if something can be imagined, conceptualized or defined then it must exist. All sorts of loony things go on my head that I thank God do not exist! Does this mean that God does not exist? That is yet to be determined (even if, obviously, I suspect He does). A purely a priori argument does not seem to be completely sound to me.