The argument than which nothing greater can be conceived

I will stop posting on the philosophy of religion soon. (logical psychologism and conceptual analysis and intuitions are probably next. Of course such discussion will be interspersed with local color!)

Anyone who’s taken an introductory philosophy course probably has been introduced to St. Anselm’s ontological argument for God’s existence and Gaunilo’s objections “on behalf of the fool” (or Kant’s objection). The general consensus is that the argument fails. But, if the argument fails, then is it an ontological argument for God’s existence?

Let me explain by re-introducing a version of St. Anselm’s ontological argument. I’ll schematize it to make it easier to understand.

1. “God”  is the being than which nothing greater can be conceived.
2. Suppose that God exists only in the understanding.
3. We can conceive of God existing in reality, even if we don’t think it actually obtains.
4. A being that exists in reality is greater than one that exists only in the understanding.
5. So, there is a being greater than the one than which nothing greater can be conceived, namely the one that exists in reality.
6. But that’s contradictory.
7. Therefore, God doesn’t exist only in the understanding; God must exist in reality.

Numerous objections have been raised against Anselm’s argument. Gaunilo’s objection is one. The problem, he says, is that we can use the construction of the argument to prove things that we have no reason to believe is true. For instance, he uses the example of the existence of a perfect island. But, since we have no reason to think that the perfect island exists and since the argument seems to replicate the ontological argument, we have no reason to think that God exists in reality.

The argument than which none greater can be conceived must have as its subject matter God. What else would it have as its target? Suppose that the argument exists only in the understanding. Since we can conceive of the greatest conceivable argument existing in reality, the greatest conceivable argument that exists in reality is greater than one that exists only in the understanding. So, there’s an argument greater than the one than which none greater can be conceived, namely the one that exists in reality. But, as with the ontological argument, that’s contradictory. Therefore, the greatest conceivable argument doesn’t exist only in the understanding; it must exist in reality.

The greatest conceivable argument would surely not have any legitimate objections to it. If it did, then the argument wouldn’t be the greatest conceivable argument. For the greatest conceivable argument would be foolproof. Since Anselm’s argument isn’t foolproof, it isn’t the greatest conceivable argument and couldn’t have God as its subject matter.

So, there’s an argument than which nothing greater can be conceived whose subject matter is God, though we may not know what the premises of that argument are.