The Conference discussions revolved, in some four or five different orbits, around the question of the reality or existence of God. The conception of God in use throughout the Conference was that of the biblical and Christian tradition. Those of the philosophers who were sceptical concerning the existence of such a Being posed a question to the religious believers. They asked them to indicate how, or in what sense, they could hold it to be reasonable or rational to believe that God exists. The sceptics were not seeking to impose any controversial or arbitrarily narrow definition of reasonableness. They were not, for example, demanding a demonstrative proof of the existence of God; and indeed it is worth noting that the familiar theistic arguments played practically no part in the discussions. The sceptics were not demanding that religious belief be justified under some canon of rationality that is peculiarly their own, but wished to learn what kind and degree of rationality a believer claims for his belief, and how he professes to justify the claim.