(December 17, 2015 at 10:15 pm)MysticKnight Wrote: No what I mean by that, is by the word "possible", it means in some possible world, it such that such and such is possible. Whatever is necessarily possible is necessarily. Therefore a necessary being being logically possible (as opposed to the may or may not exist type possible) would actually prove it to exist by this argument.
Let's put this to bed, shall we?
First, if informal logic is insufficient to demonstrate god's existence I'll take the stance that the theist already has two feet on the proverbial plank carrying enough momentum to make the result fairly obvious.
Second, I am always suspicious when someone starts deploying formal logic systems such as modal logic and its S5 axiom as demonstration of something's existence. The ontological argument is deductively valid, but in no way can its validity pertaining to the existence of god be demonstrated. What formal logic systems cannot do, by their very nature, is establish the truth of its premises; in this case the possibility of the existence of maximal excellence. It simply cannot be demonstrated and quite frankly is defined by the arbitrary characteristics already assigned to god; i.e., damn close to begging the question.
Third, as Stimbo has already pointed out, if this argument is dishonestly used to draw a conclusion about a metaphysical truth by blindly accepting an unjustified premise it can be used to prove the existence of anything. Using Stimbo's example, if a maximally great being is possible why can't a pink unicorn be possible? Hell, the argument can be used to assert that unproved mathematical conjectures must necessarily be true.
This is my muddled thinking, let's hear from the man that created this version of the Ontological Argument:
Quote:Perhaps somewhat surprisingly, Plantinga himself agrees: the “victorious” modal ontological argument is not a proof of the existence of a being which possesses maximal greatness. But how, then, is it “victorious”? Plantinga writes: “Our verdict on these reformulated versions of St. Anselm's argument must be as follows. They cannot, perhaps, be said to prove or establish their conclusion. But since it is rational to accept their central premise, they do show that it is rational to accept that conclusion” (Plantinga 1974, 221).http://plato.stanford.edu/entries/ontolo...#PlaOntArg
I left the last line of the quote in the spirit of intellectual honesty. I do not agree with the statement and think it's easily dismissed as the linked article demonstrates.
The important part here is that the professional philosopher that reformulated the Ontological Argument using modal logic admits that it does not 'prove or establish' it's conclusion. This of course doesn't stop apologists that should know better, William Lane Craig as an example, from deploying it knowing full well that most people will happily accept what they think is a sophisticated justification for a conclusion they already hold. In this respect WLC is nothing more than the dishonest lever puller behind the curtain.
