  Reid's abiding confidence in his religious belief meant that his published work on traditional issues in the philosophy of religion, such as God's nature and arguments for God's existence, is minimal. In his lectures and unpublished work, however, he vigorously attacks Hume, atheists and their arguments with surprising vitriol. The fact that Reid does not thoroughly address canonical issues in philosophy of religion in the context of his published work, despite the personal and professional importance of his religious commitments, is a conundrum. The principal source for Reid's philosophy of religion outside his published works are sets of student notes—now, a total of four transcripts—from Reid's lectures on natural theology at Glasgow in the years 1763–1780. One set has been published as Thomas Reid's ‘Lectures on Natural Theology’ (Reid 1981, abbreviated 'Natural Theology' below). This is not a definitive source of Reid's own views, but given pedagogical conventions of the time, and cross-references of materials in the Natural Theology with materials elsewhere in Reid's corpus, we can draw reliable inferences about Reid's philosophy of religion from them. In this subsection we first discuss the conundrum just mentioned, then treat Reid's novel epistemology of religious belief, and then briefly discuss traditional issues in philosophy of religion.