Godel's Ontological Proof

[eponymous]

Is anyone familiar with Kurt Godel's ontological proof for the existence of God? I read about it a few years back, but I can't quite remember the particular thrust of his argument. Any sources for the argument itself and additional critiques/analyses (by anyone) would be appreciated.

[JeffB]

Hmmm, I'd never heard of Godel's ontological argument before, even though I've studied this topic. I found this web site (http://www.stats.uwaterloo.ca/~cgsmall/ontology.html) discussing it. I haven't had a chance to read it yet, but it looks like it might be interesting. (I ran a search on Google with "kurt godel god" and got bunches of hits.)

I find it interesting that Godel would attempt such a proof. He is best known as a mathematician and author of Godel's proof, which basically states that any mathematical system contains unprovable propositions. I'd argue that the same holds for any religious system, with "God" being one of those unprovable propositions.

[bibliophage]

You might have better luck searching if you spell his name the way it's meant to be spelled: Gödel. Or maybe not, since it is very often spelled Godel, or Goedel.

[JeffB]

"Godel" seems to work find -- it picks up "Gödel" pages. I couldn't remember how to get the ö and was too lazy look it up. In this post, I just copied and pasted from bibliophage's post. :)

[Alessan]

IIRC, it's something like:

1. Existance is good
2. God is good
3. Therefore, God exists

I've probably messed up the order a bit.

[Timothy Campbell]

Hmmm, let me try Tim's Ontological Proof...

1. Cheese is good
2. God is good
3. Therefore God exists ... or he's cheese (I'm not sure which)

[MEBuckner]

The ontological proof (or argument) for the existence of God goes back at least to St. Anselm (1033-1109).

The Catholic Encyclopedia (http://www.newadvent.org/cathen/06608b.htm#IBf) sums it up thusly:
This argument undertakes to deduce the existence of God from the idea of Him as the Infinite which is present to the human mind; but as already stated, theistic philosophers are not agreed as to the logical validity of this deduction.

As stated by St. Anselm, the argument runs thus: The idea of God as the Infinite means the greatest Being that can be thought of, but unless actual existence outside the mind is included in this idea, God would not be the greatest conceivable Being since a Being that exists both in the mind as an object of thought, and outside the mind or objectively, would be greater than a Being that exists in the mind only; therefore God exists not only in the mind but outside of it.

Descartes states the argument in a slightly different way as follows: Whatever is contained in a clear and distinct idea of a thing must be predicated of that thing; but a clear and distinct idea of an absolutely perfect Being contains the notion of actual existence; therefore since we have the idea of an absolutely perfect Being such a Being must really exist.

To mention a third form of statement, Leibniz would put the argument thus: God is at least possible since the concept of Him as the Infinite implies no contradiction; but if He is possible He must exist because the concept of Him involves existence.
I suppose if I told everyone what I think of all this it would be getting into Great Debates territory (or maybe even the Pit), so I shall refrain.

[Erika]

I did some research on this last year some time, and if you're really interested, I could eventually dig up the sources. Basically, Godel took Anslem's argument, gussied it up in Modal Logic (a verison of symbolic logic that, among other things, lets you talk about necessity and possibility). To flesh it out a little more, you define God as having all the properties that are "good", and then prove the necessity of the existance of such a being.

The math is pretty sound, but the philosophy needs a bit of work--starting with his definition of "good"--it's decidedly sketchy and imprecise. But it's interesting reading, if nothing else.

I just checked JeffB's link, and that's the site I ended up relying on pretty heavily. There were others, but that one's definitely a good start.

[eponymous]

Everyone, especially, JeffB and Erika, thanks...

I was aware of Anselm's ontological proof - I just couldn't remember how Godel approached the problem.

originally posted by MEBuckner

I suppose if I told everyone what I think of all this it would be getting into Great Debates territory (or maybe even the Pit), so I shall refrain.

Hmm...I'd be interested in hearing what you think. I have some problems with it as well. Want to start a new thread in GD?

[MEBuckner]

Ah, why not?

Ontological argument for the existence of God (http://boards.straightdope.com/sdmb/showthread.php?threadid=53169)