Thread: Anselm's Ontological Argument for the Existence of God

5 follows as the result of a very simple logical inference from 2 and 4 (which has been explained a couple of times now). 4 follows trivially from 3. The argument does not say anything about, and does not assume anything about, beings which are greater than we can conceive. I left most of the reasoning behind the steps tacit because I thought things like "X or Y and not Y implies X" were simple enough to follow, but apparently it's less lucid than I thought so I'll explicate them now:

1. The idea of God exists in the mind (we can conceive of God by definition).
2. God exists in reality or God does not exist in reality.
3. Thus, God either exists in the mind alone, or, in the mind and reality (from 1 and 2).
4. It is greater to exist in the mind and reality rather than the mind alone.
5. If God exists in the mind alone, we can conceive a greater being than God, which exists in the mind and reality (from 4).
6. This is a contradiction of the definition of God.
7. Therefore God does not exist in the mind alone (from 5 and 6).
8. Thus, God exists in the mind and reality (from 3 and 7).
9. Thus, God exists in reality (from 8).

Originally Posted by Photolysis

#3 This assumes that existence is an intrinsic property of greatness.

Isn't it? At the very least there are various elucidations of greatness which make the argument sound, as I detailed previously. "Occupying larger domains of existence", for instance, or "being able to effect larger change in reality".

Originally Posted by Alric

You already admitted that it isn't true, and we already proved that it is a flawed way of thinking with the fukshit example. You keep saying the definition doesn't matter, but that is totally untrue. An argument is only valid if the premise is also valid and in this case the premise is an ambiguous definition.

This is nonsense, definitions are not premises. A premise is a proposition used to give a conclusion through a syllogism. A proposition is something of which truth or falsity can be asserted.

Which is my point, if you place in a non-ambiguous definition it stops working, because the argument relies on the ambiguity of the definition.

People don't even know what you are talking about when you say greatest. Are you talking about greatest in size? It seems to be, because it says an idea is greater in size if it takes up both the mind and reality. However, that makes no sense when talking about an idea that is being conceived and that has no size.

I've already responded to this, including providing several definitions which make premiss 3, "it is greater to exist in the mind and reality rather than the mind alone", sound, and thus the argument sound as a whole.

Originally Posted by Xei

1. The idea of God exists in the mind (we can conceive of God by definition).
2. God exists in reality or God does not exist in reality.
3. Thus, God either exists in the mind alone, or, in the mind and reality (from 1 and 2).
4. It is greater to exist in the mind and reality rather than the mind alone.
5. If God exists in the mind alone, we can conceive a greater being than God, which exists in the mind and reality (from 4).
6. This is a contradiction of the definition of God.
7. Therefore God does not exist in the mind alone (from 5 and 6).
8. Thus, God exists in the mind and reality (from 3 and 7).
9. Thus, God exists in reality (from 8).

Fine, to use this modified version.

#1 Begs the question (but as was originally presented it can't be challenged).
#6 There is no contradiction; all it actually means is that if a god existed as defined, then it would have to exist, instead of being imaginary. Of course this tells you nothing useful. At no point does this ever allow anyone to make the leap to "therefore god exists".

To annotate it:

Originally Posted by Xei

1. The idea of God exists in the mind (we can conceive of God by definition). We can imagine god
2. God exists in reality or God does not exist in reality. God is real or not
3. Thus, God either exists in the mind alone, or, in the mind and reality (from 1 and 2). God is either real or not, and can be imagined
4. It is greater to exist in the mind and reality rather than the mind alone. Real things are better than imaginary things
5. If God exists in the mind alone, we can conceive a greater being than God, which exists in the mind and reality (from 4). To be the greatest, a god would have to exist
6. This is a contradiction of the definition of God. This is incorrect. It's still conditional on there being a god in the first place. This would only be a contradiction if god existed but was imaginary, which is already self-contradicting on the basis of existence, before one considers 'greatness'.
7. Therefore God does not exist in the mind alone (from 5 and 6). This does not follow as true, it only follows if a god exists, telling you nothing
8. Thus, God exists in the mind and reality (from 3 and 7). Invalid conclusion
9. Thus, God exists in reality (from 8). Invalid conclusion

Isn't it? At the very least there are various elucidations of greatness which make the argument sound, as I detailed previously. "Occupying larger domains of existence", for instance, or "being able to effect larger change in reality".

I didn't read anything other than the OP. You could define greatness in such a way for whatever little it's worth (nothing in my opinion), but the original argument doesn't define it.