Auguste Comte (1798–1857), the founder of positivism, stood at the junction of two important traditions in European thought. One was what we might call an ‘encyclopaedic’ tradition, which aimed at the systematization of knowledge and the construction of a scientific understanding of society. The other consisted in the quest for a secular religion that would transcend Christianity by sacralizing humanity itself. The first tradition rejected theology as unscientific; the second embraced a renewed religion as the route to social regeneration (Wernick 2001: 18–19). Considered as belonging to the first tradition, Comte's main contributions to the philosophy of religion lay in his conjectural history of religion and of the modes of human consciousness. He developed his famous ‘law of the three states’, in which the theological state of consciousness gives way to the metaphysical, which in turn gives way to the positive or scientific. In fleshing out this law he made a significant contribution to the anthropology of religion by offering an account of how fetishistic forms of theological consciousness were transformed into monotheism by way of polytheism. Considered in the light of the second tradition, Comte was the inventor of the idea of a non-theistic ‘religion of humanity’, which occupied an important place in nineteenth-century religious thought. Scholars disagree about whether these two aspects of Comtes were incompatible, or two sides to the same coherent thinker. What is surely clear, however, is that a historical appreciation of Comte requires us to grasp why he considered it plausible to contemplate a synthesis of these two traditions.