Abstract. This paper is the product of an interdisciplinary, interreligious dialogue aiming to outline some of the possibilities and rational limits of supernatural religious belief, in the light of a critique of David Hume's familiar sceptical arguments -including a rejection of his famous Maxim on miraclescombined with a range of striking recent empirical research. The Humean nexus leads us to the formulation of a new 'Common-Core/Diversity Dilemma' (CCDD), which suggests that the contradictions between different religious belief systems, in conjunction with new understandings of the cognitive forces that shape their common features, persuasively challenge the rationality of most kinds of supernatural belief. In support of this conclusion, we survey empirical research concerning intercessory prayer, religious experience, near-death experience, and various cognitive biases (e.g. agency detection, theory of mind, egocentric and confirmation bias). But we then go on to consider evidence that supernaturalism -even when rationally unwarranted -has significant beneficial individual and social effects, despite others (such as tribalism) that are far less desirable. This prompts the formulation of a 'Normal/Objective Dilemma' (NOD), identifying important trade-offs to be found in the choice between our humanly evolved 'normal' outlook on the world, and one that is more rational and 'objective' . Can we retain the pragmatic benefits of supernatural belief while avoiding irrationality and intergroup conflict? It may well seem that rationality is incompatible with any wilful sacrifice of objectivity (and we appreciate the force of this austere view). But in a situation of uncertainty, an attractive compromise may be available by moving from the competing factions and mutual contradictions of 'first-order' supernaturalism to a more abstract and tolerant 'second-order' view, which itself can be given some distinctive (albeit controversial) intellectual support through the increasingly popular Fine Tuning Argument. We end by proposing a 'Maxim of the Moon' to express the undogmatic spirit of this second-order religiosity, providing a cautionary