Theories and Ideas
A traditional form of approach is that societies are functionally integrated or that linkages between social institutions depend on their related and overlapping functions. An institution such as the state may have as its core functions the preservation of order and the coordination of collective projects. A religious institution might have as its core functions the creation of societal legitimacy.
According to differentiation theories, as societies modernize they generate an increasing number of interdependent institutions. For example, in a relatively simple society, socialization could take place via the large, intergenerational family. But when the process of socialization becomes more complex – for example, when it begins to require specialized knowledge that family members do not have, new institutions must form to serve these new requirements.
Differentiation of non-religious institutions would gradually reduce the scope and autonomy of religious institutions, turning them into one institution among others rather than society’s core integrating institution.
Not all theories of differentiation are the same. Some are more actor-cantered and suggest that differentiation takes place if and when powerful individuals and groups want it to take place. There are a number of competing theories about what happens to religion in modern societies and not all of them agree about what is in need of explanation. In other words, the basic empirical description of processes is at issue though the analysis of of ideology’s role in contemporary politics is true.