A mathematical proof of God's existance . . .

[Sparko]

No need to repeat your argument for the umpteenth time, I got it the first time. What you keep missing is that while there is a chance God may exist, there's also a chance he may not. Or put slightly differently: your argument assumes there's always a possibility God may exist, but there's is a situation where this is not true, namely if in fact God does not exist. In your reasoning you ignore this possibility, and use your conclusion to justify this dismissal of possibility only afterwards, which is bad reasoning. Basically you're using the conclusion of your argument to turn the premiss "God may exist" into "God must exist", and then come to the conclusion it is true. Well, surprise!

The way you reason can be used to prove about anything exists (or can not exist!), for instance: there's always a world possible in which a Unicorn necessarily exists (you can not dismiss this possibility completely). But then such an animal must exist in all possible worlds, therefore Unicorns exist in our world.

And btw I have shown where Gödel's argument fails, for instance in post #21 (or about any other post of mine). Don't you read or understand them? Strange, since they copy your own argument.

Unicorns are not all powerful creators of the Universe, they don't necessarily exist or not exist.

I see arguing with you is a waste of time, since you don't even seem to grasp the original proof in the first place. I might as well argue philosophy with a chimp.

I am done here.

[wolper]

Unicorns are not all powerful creators of the Universe, they don't necessarily exist or not exist.

Necessarily existing Unicorns are by definition not contingent. They may be imaginary, but if they exist, they do so necessarily. And they don't have to be all powerful or creating; the reasoning you propose applies to anything that may exist necessarily, no matter how improbable, as long as it's not impossible. And since the existence of a necessary Unicorn, all powerful or not, can not be a priori disproven....

I see arguing with you is a waste of time, since you don't even seem to grasp the original proof in the first place. I might as well argue philosophy with a chimp.

Too bad. I maintain that I have understood the proof; I just don't agree with it - that's not the same thing. Any proof that uses its conclusion to support a premiss of that proof is by definition invalid (that goes for my Unicorn proof too).

Best,
wolper

[ChuckInSuburbia]

I know I'm a late comer to this party, but I feel the need to throw in my two cents...

My problem with this argument is that it starts off, right at the beginning, with an unsupported statement.

1. God can either necessarily exist, or necessarily not exist.

I actually have more than one problem with this statement. First off, what definition are we using for "god"? Without further expansion, we could get into some fuzzy, pantheistic non-explanation, like "god is love", or "god is the universe", or some other such nonsense. I have to assume that we are talking about the god of Abraham, but this is only conjecture based on knowledge of western culture.
Secondly, why are these the only two options? What examples do we have of any object which necessarily exists or necessarily does not exist? The only other "things" which can be argued to possess this quality of "necessary existence" (as far as I know) are numbers/mathematics, which are human constructs. The whole concept of necessary existence seems (to me) to have absolutely no basis in reality, and reads like pseudo-logical self satisfaction.

The only way I can see to revise this statement in such a way that it actually makes sense is this:
1. God exists, or, god does not exist.

Unfortunately, the rest of the argument is based on the concept of necessity, and thus has no basis. And, we're still stuck without a definition of "god" to work with.

What surprises me about logical arguments, like this one, is that they have been around as long as they have and the philosophical community seems to have no problem taking them seriously.

[Chrs]

First off, what definition are we using for "god"?

I believe the argument uses "All-powerful being".

Secondly, why are these the only two options?

Law of the excluded middle. (X V ¬X)

[ChuckInSuburbia]

Law of the excluded middle. (X V ¬X)

The issue here is not with the law of the excluded middle, but with the "necessary" part. While (X V ¬X) may be valid, (□X V □¬X) has problems because the two arguments are not direct opposites. If you want to add the necessity of X to the statement, you could say (□X V ¬□X). In English, either X is necessary or X is not necessary. The statement "X does not necessarily exist" is very different from "X necessarily does not exist". I hate to be a stickler, but word order does matter.

Besides this, the concept of "necessary existence" has no basis in physical reality, and has been used to demonstrate all kinds of nonsense, including the proposition that everything does, in fact, exist. Necessary existence only has merit if it can be demonstrated that other possible worlds exist as physical realities, not just concepts.

[Chrs]

The statement "X does not necessarily exist" is very different from "X necessarily does not exist".

Correct. But the necessarily not existing thing comes from Ax. 2 as a result of a property of a god. See Ax. 1 and Ax. 2

[Chrs]

Besides this, the concept of "necessary existence" has no basis in physical reality, and has been used to demonstrate all kinds of nonsense, including the proposition that everything does, in fact, exist. Necessary existence only has merit if it can be demonstrated that other possible worlds exist as physical realities, not just concepts.

Eh. The thing is is that Existence is not a property. At least, that's the generally argued thing. You're not too far off.

[ChuckInSuburbia]

Eh. The thing is is that Existence is not a property. At least, that's the generally argued thing. You're not too far off.

This sounds counter-intuitive, but let me see if I'm getting this right...
Since we're dealing with conceptual objects, we can't just state that P(x) entails the property of existence, at least not in the physical sense. Otherwise, invisible pink unicorns and such would just pop into existence all over the place.

If this is the case, how can we say that the property of "godliness" entails all positive properties, including necessary existence? And how would this differ from an assertion that the property of "fairie-ness" entails the property of existence?

And if existence is not a property in modal logic, then (it seems to me) modal logic can only be used to describe concepts, not physical objects. If this is the case, how is modal logic even useful in any practical way?

Maybe we are getting hung up in the fuzziness of the word "exists". Simply by using the word "god", or "leprechaun", or "bigfoot", I am granting conceptual existence to these beings/objects. But, that doesn't have any bearing at all on physical reality.

[Chrs]

And if existence is not a property in modal logic, then (it seems to me) modal logic can only be used to describe concepts, not physical objects. If this is the case, how is modal logic even useful in any practical way?

Existence not being a property is pretty much the only counter to some ontological arguments. The argument tends to go (about existence not being a property) is that it's redundant and the claim is be "God." and not "God exists."

I'm not a theist, you may've got this wrong, and I don't think this is a valid argument. You were just wrong

[ChuckInSuburbia]

The argument tends to go (about existence not being a property) is that it's redundant and the claim is be "God." and not "God exists."

I think I'm getting closer, or at least I hope so. I guess I was getting tied up with the multiple meanings of "exists".

I think I see what you're saying about existence as a property being redundant. When we're talking about conceptual objects, they will always have a property of conceptual existence, just by virtue of the fact that we're talking/thinking about them. However, a concept is just that, and can never "gain" physical existence, even if it is based on a real, physical object.

I have no problem with the ontological argument being used as a "proof" of god's existence as a concept. Of course god exists as a conceptual reality. The question of interest is whether such a being exists as a physical reality, and I don't see any logical arguments being useful in this regard.