The Ontological Argument - valid or debunked?

[RoadRunner79]

Oh no my post wasn't worthless, Esq, your brilliant post didn't point out the particular error Roadrunner made that I tried to point out.

I'll try to make it clearer, I write badly:

@ Roadrunner:

In Merriam Webster and a few other dictionaries, "being" "exist" are somewhat circular (referencing each other), so I would say that according those definitions your reference to a non-existing being; is incoherent.

My bolding and underlining. Bolded parts are referring to existence in general, underlined parts to a living being.

Roadrunner these two definitions of "being" are not the same:

existence.
"the railway brought many towns into being"

a real or imaginary living creature or entity, especially an intelligent one.
"alien beings"

So, these are the two definitions of "being" (existence and a living entity) you equivocated, try not to do it again as it is clearly a mistake. Being =/= a being.

@ Esq

I hope my contribution was not entirely without merit?

ETA: I say this because you're by far the superior debater of us two, and I feel like I have almost nothing left to contribute when you're involved in a debate sometimes... due to your awesomeness

I can see your point, but I see the definitions going from the general to the specific.  Interestingly, dictionary.com comes up differently for me.

[Edwardo Piet]

Consistent specifics are important if we are to consistently avoid equivocation. Equivocation is an especially fallacious of example of one of many possible recipes of misunderstanding.

[wiploc]

I think the most you can get from the argument is that God either necessarily exists or necessarily doesn't exist.

So long as you're clear that we're talking about necessary gods, then, yes, that's all the MOA proves. 

But if we go outside the MOA, and look at the definition of "possible world," then we see which of those is true. 

Since possible worlds include godless worlds, it cannot be true that necessary gods exist.  Because gods cannot exist in godless worlds.  Therefore, no existing god is necessary.  All gods defined as necessary are nonexistent.

[wiploc]

We know that there's something wrong with that logic because it can "prove" that gods do not exist just as easily as it "proves" that they do:

Premise 1: It's possible that a 'maximally great being' does not exist. 
Premise 2: If it's possible that a maximally great being does not exist, then a maximally great being does not exist in some possible world.
Premise 3: If a maximally great being does not exist in some possible world, then it does not exist in every possible world. 
Premise 4: If a maximally great being does not exist in every possible world, then it does not exist in the actual world. 
Premise 5: Therefore a maximally great being does not exist in the actual world.
Premise 6: Therefore a maximally great being does not exist.
Conclusion: Therefore God does not exist.

This second version is exactly as strong as the first version, yet it proves the exact opposite.  Any argument that proves both X and not-X is worthless.  In the scales of persuasion, its weight is zero.

We know, therefore, that the MOA (modal ontological argument) is worthless, absolutely refuted. 

Which brings us to P1.   

We're talking about necessary gods, gods that don't exist at all unless they exist in all possible worlds.  Can a god like that exist in some possible worlds? 

No.  Certainly not. 

We know that some possible worlds are godless.  We know this because of the definition of "possible world."  A possible world is any world without contradictions.  If a world doesn't have square circles or married bachelors, or anything other logical contradiction, then it is a possible world. 

There's nothing contradictory about godless worlds, so they are by definition possible. 

But a god existing in a godless world would be a contradiction, an impossibility.  Therefore, no god can exist in all possible worlds.  

Since P3 establishes that the god we are discussing, the god of the modal ontological argument, does not exist in any possible world unless it exists in all of them, it follows that this god does not exist in any possible world. 

Therefore, P1 is false. 

I'm sorry, but it makes no sense that this defeats the argument. What is the difference between Premise 1 and Premise 1'?

Premise 1: It's possible that a 'maximally great being' exists.
Premise 1': It's possible that a 'maximally great being' does not exist. 

So the real difference is in P4' (P2' and P3' are definitionally true). 

Premise 4: If a maximally great being exists every possible world, then it exists in the actual world. 
Premise 4: If a maximally great being does not exist in every possible world, then it does not exist in the actual world. 

When you apply the modal logic "if something is necessary in one possible world then it is necessary in all possible worlds" to a negative such as P4', you are saying it is necessary that something does not exist. Isn't that saying the same thing as a maximally great being is logically impossible? So to support P4', you are back to having to show that a greatest conceivable being is not logically possible--which was the original challenge of the original argument. 

I'm not sure what you're trying to say.  But I'll take a guess, and you can tell me if I'm wrong. 

Well, actually, first I want to deal with the bit about the "greatest conceivable being."  I think that's a complete change of topic.  But you say it is the original challenge of the original argument, so I went back to the OP.  I don't see that subject in the OP.  So I had my computer search the OP for "greatest conceivable being" and it didn't find it.  So I had it search for "conceivable," and it didn't find that either.  I wonder if you aren't confusing two different threads? 

Okay, back to what I think you may be talking about: 

Premise 4: If a maximally great being does not exist in every possible world, then it does not exist in the actual world.

"A maximally great being does not exist in every possible world" can be read in two different ways.  Thank you for pointing that out, if you did. 

Interpretation 1: In every possible world, the MGB does not exist; there is no possible world in which the MGB exists.  

Interpretation 2: There is at least one possible world in which the MGB does not exist. 

Feel free to use interpretation 1.  That is supported, proven, by the preceding premises.  It is consistent with the meaning of the preceding premises.  It is consistent with the meaning of the original (non-parody) version of the argument.  And it is the meaning that I intended when I wrote the parody. 

Note also that using interpretation 2 doesn't help your case.  If there is even one possible world in which a necessary being does not exist, then that necessary being does not exist at all, in any possible world.  In which case, no surprise, it does not exist in the actual world. 

So, regardless of which interpretation you use,  the result doesn't change:  Therefore god does not exist.   

[wiploc]

wiploc's argument shows that it can work both ways, that's the point. As you have yet to provide an argument that establishes the logical possibility of a maximally great being, then this argument is pretty much vacant at this point.

No. It does not work both ways because the meaning of P4' is very different from P4 because you cannot rely on modal logic of "necessary" as the original argument does.

In P3, you defined the MGB as necessary, as existing in every possible world.  If there is a possible world in which the MGB does not exist, then it does not exist in any possible world.  If it does not exist in any possible world, then it does not exist in the actual world. 

The logic works the same in both versions of the argument.  If one is valid, the other is too.  The only difference is that your version is unsound.

[chimp3]

Premise 1 : It is possible an eternal god exists
Premise 2: If it is possible that an eternal god exists , then it is possible for more than one eternal god to exist
Premise 3: If more than one eternal god exists then this universe may have more than one creator
Premise 4 : If this universe has more than one creator it would explain much of the terror and chaos
Conclusion : Ever work on a project governed by committee?

[quip]

Which it is. At best, God can be super powerful to the point that no other entity would ever exceed it in power, but not literally omnipotent.

You are not pointing out why a maximally great being is illogical.

Existence cannot be predicated...it's begging the question.

Ex. Possible purple apples exist.  The very postulation concerning this apple in question presupposes the apple's existence. In effect, making the claim that the existing purple apple...exists.    (or in this case an existing god, exists!   )

On top of that add the vagaries inherent to such abstract terms such as "all-powerful" ...and this dog don't hunt.