my personal critique of Anselm's argument

if you haven't heard of it before, the philosopher Anselm of Canterbury has this supposed proof for the existence of God (or, rather, the greatest being conceivable, which has properties similar to God's) that uses pure logic alone, a so-called "ontological argument"

i'll present the original argument first:

1. something we understand exists in our thoughts
2. so, "the greatest thing conceivable" (my words, not his) exists in our thoughts
3. such a thing could exist only in our thoughts, or both in our thoughts and in reality
4. but wait, if it only exists in our thoughts, it can't be the greatest thing conceivable, since we could think of something greater. that is, the same thing, but actually existing
5. therefore, the greatest thing conceivable must exist in reality!

okay, what? i didn't fully understand it the first time, either. but read it again. to me (and apparently to other philosophers through the ages), this seems pretty stupid. but, just saying it doesn't mean it is, so i'll have to show exactly what is stupid about it.

another philosopher, Immanuel Kant, stated that existence is not a "property." that is, something isn't "better" or "different" simply because it exists. therefore, a real "greatest thing conceivable" isn't better than a imaginary one; it is simply that one exists and the other doesn't.

even if we allow existence as a property, there is still another problem: the idea of a really existing thing does not mean the thing is really existing. so, going back to the "proof" (item 4 specifically), the idea of the "greatest thing conceivable" has the "property" of actual existence. sure, but it's still just an idea! it doesn't necessarily exist.

(it can also be noted that "greatness" is highly subjective. what i might regard as the "greatest thing conceivable" might be different from others' ideas)