Why ontological arguments are illogical

[genkaus]

Well, the argument goes something like:

If you're imagining something that has every perfection, and you're imagining something that doesn't actually exist, then the thing you're thinking of would be 'better' if it did actually exist. Hence what you were thinking of could not have been complete perfection.

'Better' isn't a necessary component of perfection either. I can imagine something perfect and I can think that it'd be 'better' if this thing never exists.

Well, moral goodness is a type of goodness, and moral perfection would be a kind of perfection (under the moral theory that these arguments are typically made under).

Immoral perfection (perfect immorality) is a 'kind of perfection' as well. So if your imagined god is required to have every kind of perfection, then he should be perfectly moral and immoral at the same time.

I think you just need to see more ontological arguments, then. Leibniz doesn't just declare that existence is a part of perfection; Plantinga doesn't couch his modal ontological argument in those terms, either.

I was referring to the terms you couched it in.

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No, I think the argument is tailored specifically to "God" defined as "that which possesses all perfections." Whether or not a particular religion's deity is identical to this same "God" depends on the properties the deity has (as well as how you decide to distinguish between objects--for example, if you hold to the identity of indiscernibles, then in order to show that a particular deity is the same as "God" amounts to showing that every proposition that is true of one must be true of the other.)

The definition itself is tailor-made for self-refutation, since mutually exclusive and contradictory properties come under the umbrella of "all".