This paper is a defense of the view that existence is a perfection. Anselm’s First Ontological Argument is referred to throughout. Two major objections are advanced: the ‘perfect island’ objection and the ‘perfect devil’ objection. A rebuttal of both, based on Anselm’s reply to Gaunilo, is tendered, but itself faces a major objection. Two lines of defense against this objection are possible. The first is sympathetically explained but it is argued that it ultimately fails. The second, which focuses on the (...) idea of a perfection and a perfect being, is elaborated and defended against a seemingly powerful objection. It is concluded that there is a reasonable interpretation of the claim that existence is a perfection. (shrink)

In this paper, I shall present and defend an ontological argument for the existence of God. The argument has two premises: possibly, God exists, and necessary existence is a perfection. I then defend, at length, arguments for both of these premises. Finally, I shall address common objections to ontological arguments, such as the Kantian slogan, and Gaunilo-style parodies, and argue that they do not succeed. I conclude that there is at least one extant ontological argument that is plausibly sound.

Millican (Mind 113(451):437–476, 2004) claims to have detected ‘the one fatal flaw in Anselm’s ontological argument.’ I argue that there is more than one important flaw in the position defended in Millican (Mind 113(451):437–476, 2004). First, Millican’s reconstruction of Anselm’s argument does serious violence to the original text. Second, Millican’s generalised objection fails to diagnose any flaw in a vast range of ontological arguments. Third, there are independent reasons for thinking that Millican’s generalised objection is unpersuasive.