A new Gaunilian objection to Anselm’s ‘ontological argument’

Abstract Gaunilo’s ‘Lost Island’ objection to Anselm’s argument in Proslogion II famously replaces Anselm’s key phrase (“something-than-which-nothing-greater-can-be-thought”) with a phrase which describes an island. The general idea is that Anselm’s argument cannot in fact demonstrate the existence of the greatest conceivable thing. For if it did, we would surely also have to accept parallel arguments which claim to prove the apparently unlikely existence of various other greatest conceivable entities. This paper introduces a new type of Gaunilian objection. Its ‘monotheist/polytheist argument’ applies the substitution method of previous ‘parody objections’ twice, proposing that Anselm’s line of reasoning can be employed to ‘prove’ the illogical existence in reality of both one-and-only-one-thing-than-which-a-greater-cannot-be-thought and two-things-than-which-a-greater-cannot-be-thought . Since the two key phrases of the monotheist/polytheist argument retain Anselm’s category of ‘something’ or ‘thing’, the argument has the advantage of being invulnerable to classic objections to Gaunilian arguments which claim that Anselm’s key phrase (“something-than-which-nothing-greater-can-be-thought”) cannot legitimately be replaced by a phrase describing the greatest conceivable thing in a sub-category of things (e.g. islands) in Anselm’s argument. The core defining feature of the new objection in this paper, however, is that it makes a stronger claim than previous Gaunilian arguments. If successful, it would show that Anselm’s line of reasoning can be taken to an illogical (and not merely unlikely) conclusion. This would demonstrate indirectly that Anselm’s argument must fail.