Gasking's proof

Abstract

The ontological ‘proof’ of the existence of God devised by St Anselm (1033–1109) is a captivating argument. God, Anselm (1973) notoriously proposed, is not merely great, but a being than which a greater cannot be conceived. To conceive God as non-existent is therefore to conceive a lesser God than the one which Anselm had in mind, for the God which Anselm had in mind is the God that exists in reality. God is just too good not to exist; his non-existence is simply unthinkable. A sophistical argument, but brilliant sophistry. Anselm’s contemporary, Gaunilo, protested that the argument is too strong (Anselm 1965). If Anselm were right then one could define a perfect anything-you-like into existence. A parallel argument, Gaunilo pointed out, could be used to conjure a perfect island into existence. Anselm’s dialectical prestidigitation appears to have extracted a substantial metaphysical rabbit from a very insubstantial logical hat. Centuries were to pass however before Hume and Kant made significant progress in developing a satisfactory analysis of the logical character of existence claims, and another century before Frege developed the formal machinery which provides a precise and technical analysis of the error.1 This well-known chapter of the history of philosophy is rehearsed here as background to a less widely known atheistic ontological ‘proof’ attributed to Melbourne philosopher Douglas Gasking (1911–1994).2 There is significant pedagogical benefit in supplementing Anselm’s classical argument for the existence of God with Gasking’s ‘proof’. Here is a reconstruction of Gasking’s a priori argument for the non-existence of God.3