Religious Diversity and Non-Religion Examined Within the Analytical Framework of a European History of Religion—Portugal as a Case Study

A large part of current sociological studies implicitly or explicitly assumes that religious diversity, non-religion, and secularisation are predominantly a question of European modernity. In a certain sense this assumption is correct, as these phenomena are growing in quantity, at least in Europe, and have become much more visible since the early 20th century. However, scholarly categories or models are always dependent on a particular discourse. If we refer to an interpretive–comparative method (Jonathan Z. Smith) and specifically to the epistemological model of a European History of Religion (Burkhard Gladigow), then we could assume that religious diversity and early forms of non-religion are almost a regular occurrence in European history, but hidden generally by a Christian discourse. The first part of the article, therefore, concerns the presentation of an analytical framework that can make religious diversity and early forms of non-religion more tangible historically and culturally. In the second part, Portuguese religious history should be re-examined based on this framework. Even if we cannot answer all questions on this complex topic, it may help us to better understand some contradictions in modern Portuguese religious history, such as the discrepancy between the population’s consistently high self-declaration as Catholic and a relatively low level of religious practice.