I argue that Kant's and Frege's refutations of the ontological argument are more similar than has generally been acknowledged. As I clarify, for both Kant and Frege, to say that something exists is to assert of a concept that it is instantiated. With such an assertion one expresses that there is a particular relation between the instantiating object and a rational subject - a particular mode of presentation for the object in question. By its very nature such a relation cannot (...) be the property of an object and thus cannot be included in the concept of that object. Thus the ontological argument, which takes existence to be a part of the concept of the supreme being, cannot, according to Kant and Frege, succeed. A secondary goal of the paper is to illuminate what I take to be an important affinity between Kant's and Frege's views more generally: that Frege's fundamental distinction between the sense and the referent of a proposition echoes, in an important way, Kant's distinction between concepts and the formal principles for their application to experience. (shrink)

In the Critique of Pure Reason, following his elucidation of the ‘postulates’ of possibility, actuality, and necessity, Kant makes a series of puzzling remarks. He seems to deny the somewhat metaphysically intuitive contention that the extension of possibility is greater than that of actuality, which, in turn, is greater than that of necessity. Further, he states that the actual adds nothing to the possible. This leads to the view, fairly common in the literature, that Kant holds that all modal categories, (...) in their empirical applications, are coextensive. I diverge from the common view. First, Kant is not committed to the coextensiveness thesis, understood as above. Instead, he espouses a weaker, epistemological version of the coextensiveness thesis, namely that what we can assert to be really possible is coextensive with what we cognize to be actual. Second, Kant's remarks are not intended to introduce a positive ontological thesis about the extensions of modal categories. Rather, he means to criticize a certain conception of modalities that was prevalent among his rationalist predecessors, i.e., the conception of modalities as various determinations that enter the intensions of concepts of things. (shrink)