How is the question ‘Is Existence a Predicate?’ relevant to the ontological argument?

Abstract

It is often said that the ontological argument fails because it wrongly treats existence as a first-level property or predicate. This has proved a controversial claim, and efforts to evaluate it are complicated by the fact that the words ‘existence is not a property/predicate’ have been used by philosophers to make at least three different negative claims: (a) one about a first-level phenomenon possessed by objects like horses, stones, you and me; (b) another about the logical form of assertions of existence; and (c) still another about a second-level phenomenon possessed by concepts when they are instantiated. I argue that only the last of these claims, originally voiced by Kant, is both plausible and relevant to the ontological argument. And I try to show that the relevance of the Kantian version comes from its providing the underlying justification for a different, and far less controversial, criticism of the ontological argument.