Here is my attempt at adding a comment that might add something useful to an ongoing
exchange of opinions.

– There are millions of Christians in the world who really believe that God exists, that He has created the universe (including man) and that the Bible tells us His thoughts and intentions.
– None of these millions of Christians has any means of proving that what they believe is right. In the course of the centuries thousands of theologians have tried the prove that their visions are right, but no one has succeeded in this.
– I think that 99% of all Christians of all sorts of denominations do not mind that their faith is not based on things that have not been proved. They take the existence of God and the truthfulness of the Bible for granted. In most cases because they were brought up that way. They learned these things from their parants and their teachers, their priests and ministers and never felt the need to doubt what these older people taught them when they were children.
– Many people have something in their mind and in their consciousness that makes them feel the need to believe in God and the Bible. They feel a need to be sure that their existence has a purpose. They feel a need to believe that things like suffering, getting old and dying are meaningful and right, if seen in a religious context. Believing in God and the Bible makes their life and the things they experience more bearable.

You actually edge up on this with your “If something is logically consistent in one world, it should be logically consistent in every world. Logical consistency is the same in all worlds.” Yes! Exactly!

If you accept the possibility of a maximally great being as defined, then that being *must* exist. But the possibility of such a being existing is an axiom!

Easy. Consider the empty world (i.e. a universe with absolute nothing in it). This world is logically consistent**.The chance of a maximally great being existing in this universe is positively equal to zero, since there is nothing in it. QED

**Okay, you could argue that the empty world is logically inconsistent. In fact, this is exactly what Plantiga wants to argue, since he’s whole point is that any universe without God must be logically impossible.

So the way I see it now is that either “Empty Universe” is logically inconsistent, or “Maximally Great Being” is logically inconsistent. But even just shedding doubt about the “maximally great being” consistency means you can’t use it in a proof, since a proof should be based on things you know for sure. You could say that even if there is a chance a “Maximally Great Being” is consistent, then it *must* be consistent. But I don’t think that works. Just because there is a chance something is consistent, doesn’t mean there is a possible world out there where it is consistent. If something is logically consistent in one world, it should be logically consistent in every world. Logical consistency is the same in all worlds. Anyway, that’s my take on it.

I have to say I am facsinated by these Ontological proofs, and the twisted, multi-layered issues that arrise. It’s amazing how close you can come to proving something from nothing.

In Plantiga’s argument, I think one problem is his maximally great being is actually logically inconsistent. No such being can exist, because, given any being, I can dream up a possible world where that being doesn’t exist (i.e. the empty world).

I could be wrong, Plantiga’s argument deals with subtle issues of modal logic. But I doubt Plantiga or anyone in the world understands all the subtleties in such a murky subject. Any such argument would have to be very clearly stated and explained before you’d ever get an atheist to buy into it.

BTW, according to Wikipedia, “Although Gödel was religious[citation needed], he never published his proof because he feared that it would be mistaken as establishing God’s existence beyond doubt.” Not really sure what that means, but it sounds like maybe he had doubts of some sort in regards to how far a priori reasoning could get you. http://en.wikipedia.org/wiki/G%C3%B6del’s_ontological_proof

You never state an ontological arument as expressed by, say, a philosopher, just your attempts to parody it. It is easy to see, through this, where you missed the mark. You have conflated a ‘maximally great being’ with ‘a person, creature, or thing that contains great attributes’. Your example of a perfectly beautiful immortal woman is not a description of a maximally great being – just a woman that is pretty. While such a woman could possibly exist, modal reasoning does not demand that she must. But, your admission that a woman with perfect beauty *could* exist is part of the argument that a maximally great being *must* exist – if it is possible for it to exist.

Let’s let Plantinga describe maximally excellent

1) A being is maximally excellent in a world W if and only if it is omnipotent, omniscient, and morally perfect in W; and

2) A being is maximally great in a world W if and only if it is maximally excellent in every possible world.

then we can go on to Plantinga’s actual argument

1) The concept of a maximally great being is self-consistent.

2) If 1, then there is at least one logically possible world in which a maximally great being exists.

3) Therefore, there is at least one logically possible world in which a maximally great being exists.

4) If a maximally great being exists in one logically possible world, it exists in every logically possible world.

5) Therefore, a maximally great being (i.e., God) exists in every logically possible world.

Or, in shorter terms, if it it is possible *AT ALL* that a maximally great being as described does exist, then that maximally great being *must* exist. Or, put yet another way, according to the rules of logic, the only way to claim there is no God is to deny any possibility *whatsoever* that God exists. Any such denial is unscientific as well as being no more or less rational than acceptance of the belief in God’s existence.

As Bertrand Russell the famous philosopher, atheist, and wit once put it, “it is much easier to be persuaded that ontological arguments are no good than it is to say exactly what is wrong with them”. The other arguments are, well, support to the ontological argument, really. If you reject the merest possibility of the existence of a maximally great being you must also reject, for example, the idea of an objective moraltiy (due to the logical implications via the argument from morality). You must also reject the possibility that there can be a cause that things exist rather than nothing exists (note: not reject that we can know the cause, or reject that there was a cause in the instance of our universe – reject that a cause is even *possible*) via implication of the Cosmological Argument.

While you are more than free to make such rejections on any number of grounds, such rejections are neither scientific nor purely logical – they are matters of choice, opinion. Personally, that’s fine by me. Heck, you can even argue with the philosophy involved. But it means that, if you are honest! you can never discount acceptance of the existence of God as, in and of itself, irrational behavior.Nor can you claim that acceptance of a belief in God is unscientific.

Kurt Godel was working on the formal structure of the ontological argument in symbolic logic *because it is much more complex than you think*. His letters reveal that he was concerned others would think him a religious man (he certainly wasn’t) but his 25+ years of study of the logic of the ontological argument convinced him it was sound.

There is actually a sort of joke amongst philosophers and logicians about the ontological argument that runs along the lines of “If you think the ontological argument a word game you don’t understand logical arguments’. Plantinga even references this sentiment in one of his books before spending about 30 pages explaining why its true.

Can you provide a specific reference for Hawking? I wasn’t aware he tried to give a priori proofs for the existence of things.

I suggest you call up Stephen Hawking and inform him that, according to you, he’s useless.If Kurt Godel were alive, you could also inform him that he is ‘laughable’ since he was working on a very comprehensive version of the ontological argument in symbolic logic when he died.

I hate to repeat this, but Anselm’s cosmological argument was less than 4 pages. As Robert Hartman said “the books written about those 4 pages in the intervening 800 years could fill large libraries”.

It is 1:45 at this time. I will write more tomorrow after I teach my classes. Hope you are having a nice weekend.