Hi, guys !
English is not my native language. I never made a class on this language. Thus, i know that this text is poor in grammar and vocabulary. I don't know if it is relevant too. Please, take a look and do what you think is better to do (including, move to trash can).
Best regards.

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I am over the Ontological Argument (OA) at least a bit per day. It appears as a magic, or a logical trap, where i can't see the key. I did read a lot of refutations of the OA, but none is really clear about where is the trick.

Some days ago, i saw an answer that William Craig gives to a person that asks about the OA. The persons asks specifically about the word possible in the first premise of the argument. He argue that, if its is possible that a Maximally Great Being (MGB) exists, then it is possible that it does not exists, after all.

Craig explains giving as example a complicated equation found on a blackboard. The equation is TRUE or FALSE. It can't be both, of course. But if the equation is TRUE, it is not possible that it is not. I think that is the trap OA uses to proof that MGB exists. The presumption that it actually exists.

Lets suppose MGB exists.

Then, the following formula is true
T1. MGB exists ==> its possible that MGB exists

And the following, is a false formula
F1. MGB exists ==> its possible that MGB not(exists)

Note that "X ==> Y" is the same of "if X then Y".

This is the trick used by ontological argument. What it really does, is take T1 and proof that it is an equivalence.

O1. its possible MGB exists <==> MGB exists         ("X <==> Y" means "X ==> Y and Y ==> X")

Nothing wrong, if we implicitly consider that MGB exists. In this case, is evident that O1 is true, despite the development of the proof.

But it is not fair, because F1 is false, only by the presumption that a MGB exist. Actually, we don't know if a MGB exists or not. Without the presumption, the ontological argument leads to a contradiction, because we will have TWO true premises.

P1. its possible that MGB exists
P2. its possible that MGB not(exists)

P1 and P2 are both true.

Starting with P1 (and forgetting the needs of substantiation of the MGB concept), we can follow the reasoning of OA and reach the conclusion :

P1. it is possible that MGB exists
A1. it is possible that MGB exists ==> MGB exists in some possible world
A2. MGB exists in some possible world ==> it exists in every possible world
A3. MGB exists in every possible world ==> it exists in actual world
A4. MGB exists in actual world ==> it exists
Therefore,
C1. MGB exists.

But if we start form P2, we get :

P2. it is possible that MGB not(exists)
B1. it is possible that MGB not(exists) ==> we cant say if it exists or not
Therefore,
C2. we can't say "MGB exists".
C3. we can't say "MGB does not exists".

I don't know what i can conclude from this contradiction.
There is any "ground" to say :

C1 is false because C2 ?
or else,
C2 is false because C1 ?