Ontological Arguments for God's Existance

Ontology is the study of the most basic or base metaphysical categories. The study of ontology seeks to place categories of reality into simple hierarchies. Therefore, ontological arguments for God's existence are derived from categories of pure logic and a priori reasoning. In this case, they seek to marry what we know with what is real.

There are a number of ways in which this argument for God's existence can be laid out, but I will focus on just a couple. St. Anselm of Canterbury's argument is probably the most famous. Essentially, Anselm's argument can be boiled down to the following:

1. God is a being that which nothing greater can be conceived.
2. Existence in reality is greater than existence solely in human imagination.
3. Therefore, God must exist in reality because if God did not, God would not be a being greater than anything that can be conceived.

Anselm observed that people have an idea of a perfect being, they can imagine a being that is so complete in its perfection that no other perfect thing can compare. How then did such a being come to inhabit human imagination if it did not exist in the first place? It got there because it actually exists. Something that does not exist is somehow lacking in perfection, thus that which nothing greater can be conceived actually exists. It seems to me, and here I agree with Karl Barth, that what Anselm is saying is that God isn't really proven by this argument, but rather that God cannot be denied once we know what He is: the most perfect being.

Later, Rene' Descartes expanded on this idea. He compares the knowledge of geometric shapes and the reality of God, writing,

But if the mere fact that I can produce from my thought the idea of something entails that everything which I clearly and distinctly perceive to belong to that thing really does belong to it, is not this a possible basis for another argument to prove the existence of God? Certainly, the idea of God, or a supremely perfect being, is one that I find within me just as surely as the idea of any shape or number. And my understanding that it belongs to his nature that he always exists is no less clear and distinct than is the case when I prove of any shape or number that some property belongs to its nature.

Clearly, as Descartes alludes, there are things that we know cannot exist--such as three sided squares--and there are things we know exist--three-sided shapes called triangles--without really giving it much thought. Because we have a clear understanding of what God is, according to Descartes, we know God exists. In other words, because the concept of God includes, by definition, the perfect goodness of God, God must exist. Because God, "a being subject to no defects whatever . . . [who] cannot be a deceiver, for it is manifest by the light of nature that all fraud and deception depend on some defect", cannot trick us into believing something that is not so and we can trust our perceptions about the world can be trusted--our perceptions of the world includes a perfect being--God must exist.

If this argument is sound, then it really does not tell us much about God in terms of our relationship with that Being. It only says that God is perfect in any conceivable way. God is all-powerful, all-knowing, eternal and entirely good.

Perhaps, that is all we can really say about God.