Rationalism and Kant's Rejection of the Ontological Argument

Kant rejects the ontological argument on the grounds that the ontological argument inescapably must assume that existence is a "determination" or "real predicate," which it is not. Most understand Kant's argument for this claim to be premised upon his distinctive proto-Fregean theory of existence. But this leaves Kant dialectically vulnerable: the defender of the ontological argument can easily reject this as question-begging. I show that Kant relies upon two distinct arguments, both of which contend that the claim that existence is a determination is inconsistent with bedrock ontological set pieces assumed by rationalist defenders of the ontological argument.