Anselm's ontological argument is a priori proof of God's existence. Anselm begins his
argument with ideas that do not depend on experience and progress to a throughly logical
explanation that God necessarily exists. Anselm's goal is to prove to the "fool" that God has to
exist. He says that anyone who has an understanding of the existence of God can and logically
has to believe that God really does exist.
Anselm starts off with a statement that is slightly simple and straight forward; God is that
thing which nothing greater can be conceived. Even to an atheist this idea is clear. Anyone, even
if they do not believe this statement, has it in their understanding that if their was a God, it
would be that thing which nothing greater can be conceived. The created cannot be greater than
the creator because the idea of the created was created by the creator and only by the creator. So
if one thinks about the possibility of a thing which nothing greater can be conceived and thinks it
possible, than that idea is in their understanding. Anselm says that it exists only in the
understanding or it exists there and in reality. That means that since everyone can conceive of the
idea of a thing which nothing greater can be conceived, than the only other group, is of people
who believe it to be true.
Suppose then, that it exists just in the understanding, then one can really conceive of it
actually existing. As Anselm asserts, " And surely than that which a greater cannot be conceived
cannot exist just in the understanding. If it were to exist just in the understanding, we could
conceive it to exist in reality too, in which ...