José Casanova’s Public Religions in the Modern World (1994) has transformed the study of religion quite considerably. As I recall, the book was received relatively slowly in its first years. Casanova’s thesis gained momentum with the escalating focus on religion after 9/11 and the ensuing publicity for Huntington’s (1996) thesis of an imminent clash of civilizations. While many only then turned to the study of religion, Casanova had already prepared the ground for a global comparative approach with his path-breaking diagnosis of the state of religion in the different modes of modernity. The growing reception of Casanova’s thesis was accompanied by the increasing interest of political science (and politics in general) in religion. In fact, Casanova has shed new light specifically on the role of religion in politics. Furthermore, his thesis on ‘public religion’ has had profound impacts on the long-lasting debate on secularization in the humanities as well as in the public domain. In this respect, there is no doubt that Casanova has contributed a major, classic work to the social study of religion.