The notion of secularization as an incompatibility between modernization and religion derives from the analysis of the process of modernization of Western European societies. This process led to a weight loss of religion in society and to a progressive differentiation of social spheres, such as religion, politics, science, etc. Following on from this analysis the category and the theory were extended to take on a universal scope in order to describe the modernization processes that would occur in other societies. From the very beginning, sociology has provided exceptions to the rule of secularization. The first was noted by de Tocqueville: American exceptionalism. Then came the processes of rapid economic growth of some Asian Pacific countries (Japan, Korea, Singapore, etc.). Progressively, the entry of new countries into the field of interest of sociologists is showing the Eurocentric nature of the concept. The case of Western Europe, which was the rule, became the exception. Even the notion of religion as a separate social sphere is considered by some social scientists to be ethnocentric. Despite its previous Eurocentrism, the notion of secularization remains useful for sociologists. It has served to account for European religious change, and its analytical instruments can be applied to other cases and may be useful for interpreting these cases either with regard to how they adhere to the Western European model, or how they differ from it – still further, if we consider the huge extent of contemporary international migration. If sociologists want to understand the new Western European societies, they must reapply this analytical rather than predictive version of the concept.