Religion is an extremely broad and complex concept. It is used to describe a wide range of social practices, from adherence to the major world religions to Rastafarianism and Scientology. The wide semantic range of the concept raises philosophical issues about how and when it is appropriate to use it. It also raises questions about what exactly is the nature of the thing that scholars are studying when they talk about religion.
The term religion was derived from the Latin religio, which means “scrupulousness,” but it did not originally refer to a cultural type or a set of social practices. It was an adjective that described people who were devoted to their gods. It could be applied to anyone who kept the taboos, made the promises, or felt the obligations imposed by their gods.
Scholars have discussed how to define religion both substantively and functionally, and many have opted for single criterion monothetic definitions such as Edward Tylor’s minimum definition of belief in spiritual beings or Paul Tillich’s idea of ultimate concern. These approaches are not necessarily wrong, but they do fasten on a particular property as the defining characteristic of religion and they may overlook important features of some religions.
There have been more recent attempts to shift the debate about how to define religion by arguing that the problem is not that there are too few or too many religious phenomena but that there are problems with the way we think about the phenomenon of religion itself. One of these problems is that we are too focused on beliefs in invisible, subjective mental states and not enough on the institutional structures that generate those beliefs.