Religion is an essential aspect of human culture that manifests itself as a range of beliefs, behaviors, and practices. The word itself derives from the Latin religio, meaning “scrupulousness” or “devotedness”. In ancient times, people referred to themselves as religious in response to taboos, promises, curses, oaths, and other commitments they had made that reflected their dedication to gods.
In the nineteenth century, anthropologists began to use the term to describe what they saw in their studies of cultures. The work of anthropologists like Clifford Geertz and Emile Durkheim suggested that religion could be defined functionally as the beliefs and practices that unite a group into a moral community (whether or not they involve belief in any unusual realities). Such definitions are called “functional” because they do not depend on belief in a particular kind of reality to qualify as religion.
There is considerable variation among scholars in their approaches to defining religion. Some adopt a polythetic approach, which allows that any phenomenon that has a large enough set of features might be considered to be a religion. Others, particularly in the scholarly field of religious studies, prefer a closed polythetic or monothetic approach.
Substantive definitions are generally viewed as being too exclusive, since they exclude a wide variety of beliefs and behaviors from the category of religion. Functional definitions, on the other hand, tend to be too inclusive, since they allow that any behavior or belief might qualify as a religion if it has the right kind of function.