This paper argues that there is a defective understanding of the sociological secularization process and a liberal tradition that takes for granted many problematic notions and subtly determines the logic of the debate on religion in modern societies. While the two issues are not causal factors for the rise of radical right-wing populist movements, they constitute the framework within which the debates on ethno-religious pluralism and its relationship with politics take place. These two unresolved questions hinder a good understanding of the complexity of social phenomena related to religion in contemporary Western societies such as fundamentalism, terrorism, political Islam or the claims of other religious groups to participate in the publ...