The Ontological Argument for The Existence of God
The Classical Arguments for God's Existence
Among these classical arguments are the Ontological, the Cosmological and the Teleological. I'd like to focus this article on the two main forms that the Ontological Argument take and then make clear the logical fallacies that leave the argument, whatever slight variations exist in it's form, moot.
Anselm and Descartes
St. Anselm of Canterbury in the eleventh century postulated the argument thusly in his work "Proslogion";
1.God can be conceived of in the mind and is by definition a being that than nothing greater than can be conceived.
2. If such a being can be conceived of in the mind then an even greater being must exist in reality because such a being would be more perfect if it existed in both the mind and reality rather than only in the mind.
3.Thus God exists.
Descartes wrote a few versions of this argument and published them in the seventeenth century. (I had a Undergrad professor who theorized that he only published what he knew to be a fallacious argument in order to appease the Catholic Church so he could carry on with his dissection of human cadavers and study of anatomy and physiology, unmolested) His argument ran thusly;
1. God is by definition the most perfect being that can be conceived.
2.Surely existence is more perfect than non-existence.
3.Thus god exists.
Now if these argument leave you scratching your head and feeling as if your were just cleverly duped, well...you were. The ontological argument is a very subtle form of casuistry that has frustrated theological debate for hundreds of year. As Bertrand Russell put it, "It is easier to be convinced that the argument must be fallacious than to find where the fallacy lies."
Logical Flaws within The Argument
I would contend that the fallacies within the arguments are threefold.
The first lies in the idea of conceiving of a perfect being. I'd like to posit that this is not possible to do and so this argument doesn't quite even get off the ground. Or at least it's not possible to imagine a universally perfect being regarded as such by everyone. Colin Mcginn, a contemporary British Philosopher, likened it to trying to imagine the most perfect meal. Not the most perfect meal you've ever had or your idea of the most perfect meal but a universally agreed upon perfect meal. What would such a meal look like, what traits would it possess, what would it be comprised of? A concept cannot even be formulated, such is the case with a universally agreed upon perfect being.
There is also a bit of sophistic slight of hand when we say that a perfect being would be more perfect if it existed than if it did not. This is not necessarily true upon closer inspection. In Platonic thought non-existence was a necessary caveat for any perfect thing. For example the perfect triangle or the perfect chair only exist in the mind but never in reality.
But the main fallacy in the argument is that it begins with the given that it is trying to logically deduce. Namely, "A perfect being exists." Anyone who has studied symbolic logic would recognize this as circular reasoning. While it is true that if god existed he would be a perfect being, this does not necessitate the existence of any perfect being existing a priori (before the fact). It equates to something like a logical whole-cloth fabrication of god.
So to sum up, a perfect being of universally agreed upon characteristics is not conceivable, perfection does not necessitate existence, and you cannot start with the premise you are trying to deduce as an initial given. For these reasons this, albeit insidiously clever, argument falls apart. And it doesn't take a Philosophy major to immediately sense that their is something huckster-ish going on here when you first hear the argument.