Religion is the set of beliefs and practices that claim to have a special relationship with God. The term has no one defining property, and it is not true that every culture will have the same religions or that all religions are the same in the same ways. This is why many scholars divide into monothetic and polythetic approaches to the study of religions. Those who take the former view hold that there is a single, unifying principle or theory that all religions must have, and those who take the latter view argue for an approach that recognizes that a religious system will always vary within cultural contexts.

In antiquity, the word religio was used in the sense of scrupulous devotion to a particular deity. As Christians developed monastic orders in which people took vows to live under a particular rule, the concept of religio was adapted to refer to a specific type of social practice. Today the range of practices categorized as religion is so diverse and so wide that some scholars—particularly those who take a Foucauldian or post-colonial approach to the study of religions—have concluded that the concept of religion does not serve any useful purpose as a scientific category and should be dropped.

However, other scholars—particularly those who take a more classical or prototypal approach to the study of religions—have maintained that while it is possible for different religious systems to vary in their beliefs, practices, and values from one another, these variations should not be seen as evidence that one or more of them has a “true” form. In the light of this, they have argued that it is legitimate for anthropologists to continue to use the concept of religion as a way of sorting the variety of religious activities out there.

While these contrasting viewpoints do have their merits, they also raise two philosophical issues that should be taken into account when discussing the study of religion:

The first is whether it is possible to understand and define religion as an abstract concept. The second is the broader issue of whether it is possible to have a meaningful and scientific concept that sorts out cultural types as well as a term such as “literature” or “democracy” does. A brief history of how the concept of religion has been shaped and misshaped by cultural, historical, and political forces suggests that these are problems with which the discipline of religions will have to grapple in its study of world religions.