There are good reasons to think that at least a part of Hume's project in the ‘The natural history of religion’ was to buttress a philosophical critique of the reasonableness of religious belief undertaken in other works, and to attack a fundamentalist account of the history of religion and the foundations of morality. But there are also problems with supposing that Hume intended to achieve either of these goals. I argue that two problems in particular – accounting for Hume's neglect of revelation, and accounting for his remarks on the ‘invincibility’ of the reasons for ‘genuine theism’ – can only be resolved by recognizing that Hume's purposes in ‘The natural history’ were not fundamentally critical. If I am right, Hume's purpose was mainly to explain why ‘false’ or ‘adulterate’ forms of religious belief are so widespread and so influential.