Ontological Argument
 

Does anyone subscribe to this philosophical idea as proof that a god must exist?

Ontological Argument:
It is self contradictory to deny that there exists a greatest possible being ie. god

Well, the more complete argument would be something like the following:

1. God is, by definition, the greatest possible being.
2. As the greatest possible being, he has all perfections. (That is, all properties which it is better to have than not to have -- power, goodness, etc.)
3. It is better to exist than not to exist.
4. Therefore, God has the property of existence, and has it necessarily.
5. Objection -- Actually, all that proves is that if God exists, he exists necessarily.
6. God possibly exists. Let's cash this out as "There is a possible world in which God exists."
7. But then God exists necessarily in that possible world.
8. So God exists in all possible worlds.
9. The actual world is a possible world.
10. Therefore, God exists in the actual world.

I'm not sure if it works or not. The most common objection (after "Hey! That can't possibly work! -- which isn't actually a valid objection :)) is that existence isn't a property, which I don't think I buy. Another possible objection is to dispute the use made of possible worlds, but that's outside of my competency.

(NB: This version of the argument can be found, in a better form, in Alvin Plantinga's book "God, Freedom, and Evil".)

6. God possibly exists. Let's cash this out as "There is a possible world in which God exists."
7. But then God exists necessarily in that possible world.
8. So God exists in all possible worlds.

8 is wrong. god only exists in the possible worlds in which he he does exist, because, if he doesn't exist, it is not necessary that he exist

Firefly, that's not quite right. If something exists necessarily, it exists in all possible worlds. That's just what it means to exist necessarily. (If you buy possible world semantics, which most (analytic) philosophers do).

but according to those arguments god only exists necessarily under the assumption that he exists and he is perfect, and those are not reasonable assumptions

I think the largest objection, if I may call it that, to the argument comes, as asaris pointed out, do we accept existence as a perfection/property?

Since no one else has picked at it, number three bothers me. Why, pray tell, is it better to exist than not to exist?

The human mind has some rather biased opinions on this. Just because we exist doesn't mean that its better than not existing. This is the same faulty logic that assumes god is sentient and has an ego and consciousness. Its just divine anthropomorphism. The Greek pantheon applied to a monotheistic idea.

Simply cause existence presupposes all else, remove existence from any doctrine and you are left with nothing. Without existence, the ideas of better and worse have no meaning.

Wow! Talk about a circular argument: To sum up those ten points: If God exists, he exists.

Philosophical arguments for God are good, but they don't replace proof (to which I do not believe there is any). I think it's all a matter of faith.

I always smile when I think of the babel fish though....


:D

I agree, scientific proof would be rather difficult, far as I can tell, it would require the ability to sense something other than energy that can do things. In other words, something outside of the laws that control this universe. The Babel fish proof is damned good though, too bad this planet doesn't have one...

Since those are beyond us right now, looks like it's philosophical proof, and the only way to do that is have everyone agree on the precedents, not an easy thing to do.

This argument has been refuted hundreds of years ago. Bringing it up in a philosophical discussion nowadays is like drawing a sword against a tank. It is a circular argument, and therefore worthless.

It's a notoriously difficult argument to refute -- as nietzsche pointed out, the most used 'refutation' is Kant's -- that existence is not a property. But it keeps coming up. The Plantinga book I cited was written in the 1970s. The problem with claiming existence is not a property is it's then hard to say exactly what it is.

It's certainly not circular, or, at least, not obviously so. "God exists" nowhere shows up as a premise, so if you're going to claim it's circular, you have a bit more work to do.

Firefly wrote:
No, the assumption is that he exists in some possible world. That's not the same thing as assuming he exists. The other 'assumption' you accuse the argument of (that he's perfect) is closer -- what it claims is that if God exists, he is perfect. It can assume that, because that's just what we mean by the word 'God'. If there was a really, really powerful being floating around somewhere, who did most of the things traditionally attributed to God, he still wouldn't be God, since he wasn't perfect. God means, by definition, the perfect being.

it's ridiculous how obviously circular that argument is. i really can't believe you can't see it.

7. But then God exists necessarily in that possible world.
8. So God exists in all possible worlds.

how can you make that leap from 7 to 8? god only exists in the possible worlds in which he exists, and those are also the only possible worlds in which it is NECESSARY that he exists. watch what happens if i change number 6 and do the same crap you did..

6. God possibly does not exist. Let's cash this out as "There is a possible world in which God does not exist."
7. But then God does not exist in that possible world.
8. So God does not exist in any possible world.
9. The actual world is a possible world.
10. Therefore, God does not exist in the actual world.

Hmmm. I have problems with:

3. It is better to exist than not to exist

I guess existence can be a property; after all we talk of fictional characters all the time:

Holmes is a detective.
Holmes does not exist (? add "in the real world")

I think the arguments about "surely God could exist in some possible worlds and not others" are answered by the fact that the "proof" is a priori and hence if it works in one possible world, it works in all - ie necessary.

However, I prefer to stick with the Douglas Adams approach:

"I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."
"But," says Man, "the Babel fish is a dead giveaway isn't it? It proves you exist, and so therefore, you don't. Q.E.D.."

what's the point of having multiple possible worlds if they're all exactly the same?

If God was perfect, he wouldn't have made humans because his perfection means that he has no desires because he is already perfect. Therefore, God doesn't exist.

They're not all the same -- in fact, if two possible worlds are the same, they're the same possible world. But if a fact is necessarily (like, relatively uncontroversially, 2 + 2 = 4), it's true in all possible worlds. So, for example, there's a subset of possible worlds in which I exist. There are some possible worlds where I don't exist. But in all possible worlds, the statement "For all x, if x is a man, x is mortal" is true. Similarly, the Ontological Argument attempts to prove that the statement "God exists" is necessarily true.

My roommate suggested that I should point out that the original intention of the Ontological Argument (found in the Monologion by St. Anselm) was not to prove the existence of God, but to explore what he's like.

EXACTLY, they aren't all the same. it is only necessary that he exist in the possible worlds in which you have already established that he exist. IT IS NOT NECESSARY THAT HE EXIST IN THE OTHER POSSIBLE WORLDS.

They're only exactly the same for theorems you can prove a priori - ie those which are necessarily true.
ie in all possible worlds, 2+2=4 (assuming we are taking all to be 'all logically possible'). You can prove that without any reference to the world itself - it is 'a priori' and therefore necessarily true; true in all the worlds.
A fact like "grass is green" cannot be proven by simply using the axioms of the system - you must refer to the possible world itself; ie "grass is green" is true iff grass is green. It is only true in a limited subset of possible worlds.
So "necessary" statements are true in all possible worlds, whereas "possible" ones are only true in some - so they're not all the same.

The bit I like about the ontological argument is its ability to prove almost anything:

eg define a Unicorn as "the most perfect horse", and start at step 3. Hence unicorns exist, and do so necessarily!

so.. in your words, the ontological argument says "god exists iff god exists"

wow! How did such a riduculous line of reasoning ever manage to get such a fancy name?

I can't really add anything since I'm not a philosophy buff, but I can note that this is one of the more interesting theological debates I've read on here to date. Thanks, guys! :thumbsup:

Anyway, I'd say that as a philosophical argument, it fails to regard the naturalist fallacy (I hope this is the universal name for it), in that it relies on theory (i.e. God is perfect because that is most desirable -- which it may very well not be), to base an argument. In essence, it's using a theory that can't discriminately be disproved to prove another point.

This is a terribly constructed thought, so I will simplify.

"Man cannot see Planet X without optical aids."

You can't disprove that, so it must be correct. In essence, this is exactly what I see the Ontological Argument doing in terms of Divine Existence.

Blah. I hope after a 9-hour workday this makes a shred of sense.

Firefly--

You don't understand the argument. Steps 4 and 5 are what you take to be the conclusion of the argument. The rest of the argument deals with your objection.

Cliche--
That objection doesn't really work. The 'most perfect horse' would have to have all perfections. Since these perfections include omnipotence and omniscience, the 'most perfect horse' would actually be God. Or, assuming you mean rather a horse that exemplies 'horseness' perfectly, it would not exist, since having all perfections is not required by our concept of horse.

CSflim--
Well, because people keep trying to refute or resurrect it. In addition to Anselm, famous philosophers who have made use of some version of it include John Duns Scotus, Descartes, and Plantinga. Famous philosophers who have tried to refute it include Gaunilo and Kant. But, while it certainly looks ridiculous on the face of it, it's notoriously hard to refute.

There's an apocryphal anecdote about the atheist philosopher Betrand Russell. One day, as he was going for a walk, thinking about how to refute the Ontological Argument, he exclaimed, "It works!" and dropped his pipe. Apparently later he figured that that conclusion was a mere mental aberration.

well, god being perfect isn't theory, it's definition. with that in mind, i have no problem with that part of the argument

asaris, I don't understand the jump from 7 to 8. It seems to me to say "If something could exist, it does exist. Perhaps you could try to elaborate on how to go from

7. But then God exists necessarily in that possible world.

to

8. So God exists in all possible worlds.

1. SOME MEN have BLACK hair.
2. JOHN is a MAN
THEREFORE:
3. JOHN has BLACK hair.
:confused:

Time to nitpick, but why would the "most perfect horse" have omniscience and omniptence? What does a horse need with said characteristics? To me, and Plato, the most perfect version of some concept is the idealized version. In essence, an omniscience and omnipotent horse would be an imperfect horse simply because it outsteps what a horse should be capable of.

There is another argument as to the redundancy of saying omniscient and the following it with omnipotent. By default, if one knows everything, then one is going to be able to accomplish anything. In other words, if you wish to commit some act and are omniscient, you will, by default, know how to perform said act given your circumstances. Thus adding omnipotent to omniscient is a tad redundant.

i think it's possible to be omniscient without being omnipotent, but not to be omnipotent without being omniscient

CSFlim the jump is because you've made the proof from axioms only: ie the proof is valid in all possible worlds because it does not refer to facts about the world itself. Therefore, if it holds in one (which personally, I reckon it does not) it would hold in all - ie necessary.

asaris I like your objection to my horse. Perhaps I need to define something like: A unicorn (OK, probably not really a unicorn any more) is the most foo horse, where foo is a property denoting having-horn-ness and existence ;)

(seriously)
We're basically saying it works for any property where 'existence' increases that property in some way. So we can define ourselves any number of arbitrary properties which include existence in some way, and prove that something exists with that property... ?

moonduck - a brain-in-a-vat (I love philosophy!) could be omniscient without having the power to actually do anything about it, surely?

maybe because of people like you who just don't seem to listen to what CSFlim and i are saying..

actually, after a short google search, it's because what you wrote isn't the ontological argument... and what you wrote is obviously wrong

here's the real one (at least according to http://www.utm.edu/research/iep/o/ont-arg.htm ):

1. It is a conceptual truth (or, so to speak, true by definition) that God is a being than which none greater can be imagined (i.e., the greatest possible being that can be imagined).

2. God exists as an idea in the mind.

3. A being that exists as an idea in the mind and in reality is, other things being equal, greater than a being that exists only as an idea in the mind.

4. Thus, if God exists only as an idea in the mind, then we can imagine something that is greater than God (i.e., a greatest possible being that does exist).

5. But we cannot imagine something that is greater than God (for it is a contradiction to suppose that we can imagine a being greater than the greatest possible being that can be imagined.)

6. Therefore, God exists.

Well, now that appears to be an argument! at leats it sort of makes sense on some level! Not that I agree with it mind, but at least it puts forward something which has the appearance of being logically sound.

More later...

well, the fallacy i see in that argument is that it works on the assumption that the a being than which none greater can be imagined exists

What we are proposing is first of all a concept of god. We shall refer to this as Conceptual God...as opposed to Real God.
This Conceptual God "exists" within our minds. The word "exists" is used in the argument to take on far too literal a meaning. For to me a conceptual existence and an actual (?) existence are qualitatively different things.
To elaborate, this conceptual existence seems to imply a reality completely encapsulated by our (collective?) thoughts. It is reminiscent of the "Platonic Reality" of mathematical abstractions (does a perfect circle really exist somewhere?). We are "placing" Conceptual God into a "place", namely the Conceptual reality.
However, we are not in any way confining this Conceptual God in any way by placing it into the Conceptual Reality. This is where the argument hinges on. By placing the Conceptual God into this conceptual reality, we are confining its "powers". as such a Conceptual God cannot allow itself to be constrained by its Conceptual reality, and must "break out" into the real reality, and become the Real God (or simply cease to exist!)
However, there is no confinement in the Conceptual reality, as it doesn't literally "exist", in a similar way that mathematical abstractions do not literally. This conceptual reality is an abstraction of our real reality. In effect we can "place" anything from Real Reality into this Conceptual Reality. So Conceptual God can indeed be perfect and omnipotent and omnipresent within the framework of our defined reality. But we must always remember that this reality does not literally exist!
As such, we may "project" our Conceptual Reality onto The Real Reality, but it will always remain the Conceptual Reality. Similarly, though we may project our Conceptual God onto a Real God, it does not validate the existence of Real God, as the projection remains within the conceptual reality! :crazy:

eeerrrkkk...I was right about it being difficult to put into words! But that is what you get when you come up against tightly formed arguments composed of anti-logic. Maybe I’ll try again later!

"moonduck - a brain-in-a-vat (I love philosophy!) could be omniscient without having the power to actually do anything about it, surely?"

Not really. Let's say our Brain-in-a-vat wanted a cold one. Sans hands, our BIAV could surely not get one for itself. If said BIAV was omniscient, then it would surely know some technique to, say, use untapped potential in the human brain of telekinesis. Thus knowing how to do telekinesis, the BIAV could simply use the power of its' mind to obtain the necessary cold one and, well, pour it into the top of the Vat.

If you know everything, you are everything.

umm.. not if that untapped potential for telekinesis doesn't exist... but i guess once the BIAV stepped in, this argument became less than serious

Pretty much my point, glad you caught it. Still, I would say that once omniscience and omnipotence were brought up, the argument became less than serious. When such absolutes are introduced into arguments, one begins to turn down the path of irrelevance.

moonduck- as firefly mentions, you're kind of assuming the human mind is capable of telekinesis.

And surely pouring a cold one right on top of some poor BIAV is going to cause all sorts of hassle for the evil demons ;)