On the Logic of the Ontological Argument∗

Saint Anselm of Canterbury offered several arguments for the existence of God. We examine the famous ontological argument in Proslogium ii. Many recent authors have interpreted this argument as a modal one.1 But we believe that Jonathan Barnes has argued persuasively that Anselm’s argument is not modal.2 Even if one were to construe the word ‘can’ in the definite description ‘that than which none greater can be conceived’ in terms of metaphysical possibility, the logic of the ontological argument itself doesn’t include inferences based on this modality. In this paper, we develop a reading of Anselm’s Proslogium that contains no modal inferences. Rather, the argument turns on the difference between saying that there is such a thing as x and saying that x has the property of existence. We formally represent the claim that there is such a thing as x