Since it’s come up a lot, here’s a recent discussion of Anselm’s Ontological Argument in the philosophical literature (via OPP).
Millican, P. (2004). The one fatal flaw in Anselm’s Aagument. Mind, 113, 437-476.
Anselm’s Ontological Argument fails, but not for any of the various reasons commonly adduced. In particular, its failure has nothing to do with violating deep Kantian principles by treating ‘exists’ as a predicate or making reference to ‘Meinongian’ entities. Its one fatal flaw, so far from being metaphysically deep, is in fact logically shallow, deriving from a subtle scope ambiguity in Anselm’s key phrase. If we avoid this ambiguity, and the indeterminacy of reference to which it gives rise, then his argument is blocked even if his supposed Meinognian extravagances are permitted. Moreover it is blocked in a way which is straightforward and compelling (by contrast with the Kantian objections), and which generalizes easily to other versions of the Ontological Argument. A significant moral follows. Fear of Anselm’s argument has been hugely influential in motivating ontolgical fastidiousness and widespread reluctance to countenance talk of potentially non-existing entities. But if this paper is correct, then the Ontological Argument cannot properly provide any such motivation. Some of the most influential contributions to ontology, from Kant to Russell and beyond, rest on a mistake.
Yujin Nagasawa, Millican on the Ontological Argument
Peter Millican (2004) provides a novel and elaborate objection to Anselm’s ontological argument. Millican thinks that his objection is more powerful than any other because it does not dispute contentious ‘deep philosophical theories’ that underlie the argument. Instead, it tries to reveal the ‘fatal flaw’ of the argument by considering its ‘shallow logical details’. Millican’s objection is based on his interpretation of the argument, according to which Anselm relies on what I call the ‘principle of the superiority of existence’ (PSE). I argue that (i) the textual evidence Millican cites does not provide a convincing case that Anselm relies on PSE and that, moreover, (ii) Anselm does not even need PSE for the ontological argument. I introduce a plausible interpretation of the ontological argument that is not vulnerable to Millican’s objection and conclude that even if the ontological argument fails, it does not fail in the way Millican thinks