Dan Barker on The ontological argument

Barker treats the ontological argument as one of the clearest examples of what goes wrong when theology substitutes wordplay for evidence. Defining God as the greatest conceivable being and then concluding that he must exist because existence is greater than nonexistence is, in Barker's view, a parlour trick that confuses the concept of a thing with the thing itself.

He has noted in debates that the same logic could be used to prove the existence of anything. If we define a maximally great island as one that exists, does it follow that there is such an island? If not, then the argument's logic is flawed — and the flaw is the same whether applied to islands or to God: you cannot define things into existence.

Barker connects this to the broader epistemological point that existence is determined by evidence, not by definition. The ontological argument is internally consistent — if you accept its premises, the conclusion follows. But the question is whether the premises are true, and that is precisely what cannot be established by defining terms. The argument is valid but not sound, which makes it logically interesting and evidentially worthless.