Is an Ontological "proof" of God even possible?

[GurrenLagann]

I recently read an interesting book by a philosopher named James Holt called "An Existential Detective Story: Why Does the World Exist?" In it, he explored his history with something/nothing question with various responses from physicists to Buddhists (it was a pretty good read).

At one point, he arrived at Platinga's Ontological argument for God's existence (if you've seen a Bill Craig debate you've heard it before). What he said that intrigued me (IIRC) is that in the paper in which Platinga originated his argument, Platinga himself noted that his argument does not in fact work as a "proof" for God's existence. I believe Holt said something like the following (I don't have the book currently):

-If there is a possible world in which there is no maximality, said being cannot exist there. Therefore, if there is a possible world in which that being doesn't exist, it cannot exist in any possible world since by definition it would have to exist in all of them.

Platinga noted this in said paper (and funnily enough we get "professional philosphers" like Craig still using it), but this leads to me wondering, is a valid and sound, God-supporting, ontological proof even possible to begin with?

[Plu]

You can't prove something that isn't defined, at all. Until people start explaining what they mean with "god", it's pointless to even try.

[the_antithesis]

is a valid and sound, God-supporting, ontological proof even possible to begin with?

No.

One cannot first define the thing as something that must exist and then expect a valid proof to come from that fallacy.

[ApostateLois]

"God?" What is "God?" Is it an old, angry, bearded man in the sky? The sky is the atmosphere, not a solid object where people can walk around, so we know for a fact that there is no bearded magic-man up in the sky. So what is meant by the three-letter sound bite, "God?" You will get as many different definitions as there are religions and denominations and cults. It is similar to the word, "spiritual," which can mean pretty much anything you want it to--and a word that can mean anything, actually ends up meaning nothing at all. Therefore, God is nothing at all, at least until all these religious nutbags can agree on a definition that doesn't include "that which must exist because things are pretty and they wouldn't be pretty if someone hadn't made them that way."

[Alaric I]

Possibility he exists? Sure. Proof of this existance? Nope.  As everyon here has stated, you must first define him to prove him. You also have to take a look at argument you posted about maximality.  He cannot exist here, therefore we cannot truly define him.  The only place he could exist is in an alternate universe somewhere that has rules of science completely different than ours.

[NitzWalsh]

You can't argue a thing into existence. The ontological arguments are basically syllogistic fallacies. If they count as proof I can prove unicorns exist.

[Poison Tree]

I simply use the form of the Ontological argument to argue-into-existence other things, showing the ridiculous nature of the Ontological form:

Our understanding of Hercules is a warrior than which no greater can be conceived.
The idea of Hercules exists in the mind.
A warrior which exists both in the mind and in reality is greater than a warrior that exists only in the mind.
If Hercules only exists in the mind, then we can conceive of a greater warrior —that which exists in reality.
We cannot be imagining some warrior that is greater than Hercules.
Therefore, Hercules exists.

Our understanding of Stinky Pete is a smell than which no greater can be conceived.
The idea of Stinky Pete exists in the mind.
A smell which exists both in the mind and in reality is greater than a smell that exists only in the mind.
If Stinky Pete only exists in the mind, then we can conceive of a greater smell—that which exists in reality.
We cannot be imagining some smell that is greater than Stinky Pete.
Therefore, Stinky Pete exists.

[NitzWalsh]

[spoil:3e2h2225]I simply use the form of the Ontological argument to argue-into-existence other things, showing the ridiculous nature of the Ontological form:

Our understanding of Hercules is a warrior than which no greater can be conceived.
The idea of Hercules exists in the mind.
A warrior which exists both in the mind and in reality is greater than a warrior that exists only in the mind.
If Hercules only exists in the mind, then we can conceive of a greater warrior —that which exists in reality.
We cannot be imagining some warrior that is greater than Hercules.
Therefore, Hercules exists.

Our understanding of Stinky Pete is a smell than which no greater can be conceived.
The idea of Stinky Pete exists in the mind.
A smell which exists both in the mind and in reality is greater than a smell that exists only in the mind.
If Stinky Pete only exists in the mind, then we can conceive of a greater smell—that which exists in reality.
We cannot be imagining some smell that is greater than Stinky Pete.
Therefore, Stinky Pete exists.[/spoil:3e2h2225]

This makes me wish there was a "like" button.