God and the Bayesian Conception of Evidence

Contemporary arguments for and against the existence of God are often formulated within a broadly Bayesian framework. Arguments of this sort focus on a specific feature of the world that is taken to provide probabilistic evidence for or against the existence of God: the existence of life in a ‘fine-tuned’ universe, the magnitude of suffering, divine hiddenness, etc. In each case, the idea is that things were more likely to be this way if God existed than if God did not exist—or the other way around. Less attention, however, has been paid to the deeper question of what it takes for something to count as evidence for or against the existence of God. What exactly is being claimed when it is said that some feature of the world is more or less likely given the existence of God, and how should we go about assessing such a claim? This paper is about epistemological issues—and in particular, certain potential cognitive errors—that arise when we reason probabilistically about the existence of God. The moral is not that we should refrain from reasoning in this way, but that we should be mindful of potential errors when we do.