Kant on the Notion of “Being” İlhan İnan Bogazici University, Department of Philosophy In his Critique of Pure Reason Kant attempts to refute Descartes' Ontological Argument for the existence of God by claiming that "'being' is not a real predicate". In this essay I wish to explore what Kant means by this, what arguments he gives in support of it, and whether by this claim Kant anticipates the Frege/Russell view that existence is a second- order concept. 1 I An important heritage that remains from The Linguistic Turn is the Existential Quantifier. Frege and Russell independently came to the same conclusion that existence is not an ordinary concept that ascribes a property to a particular object. Frege analyzes existence as a “second level concept”; a proposition in the form "F exists", according to Frege, should be analyzed as "There is at least one object that falls under the concept F". Similarly a negative existential claim in the form "F does not exist" turns out to subscribe to the concept of F being empty. 2 In a similar vein, Russell takes existence to be a property of a "propositional function” 3 which comes close to, and perhaps is the same as Frege's "concept" (which Frege defines as functions from objects to truth values). For both philosophers an existential claim makes no reference to an object, which allows them to solve the time honored Riddle of non-being. For instance if the sentence "God exists" makes reference to God, then the same should be expected of its negation "God does not exist", which in effect would lead to a contradiction. Therefore in both of those sentences, there is no reference to God, on the Frege/Russell view, but only a reference to the concept God; the first says the concept is not empty and the latter says that it is. Today perhaps there is no philosopher who denies that this is at least one good use of the existence predicate. İnan, İlhan, “Kant on the Notion of 'Being'”, Immanuel Kant, Muğla University International Kant Symposium, Vadi Yayınları, 2006.