A social phenomenon that encompasses a diverse range of practices, Religion is a contested concept, which has become a synonym for “belief in gods.” The term also is used to describe a particular group of beliefs or the world view of a specific region. Ordinary language definitions of Religion, however, are ambiguous and limiting, and do not provide the kinds of properties that are needed to understand this class of phenomena.

A useful way to approach this concept is to consider how one would sort a collection of objects by their properties, a practice that is familiar from the work of natural scientists such as biologists or chemists. This is what is called a polythetic approach, and it allows for the emergence of family-resemblance concepts that can discriminate among phenomena.

This approach is particularly useful because it provides a clearer picture of the many different ways in which people have organized their lives. Whether they believe in one god or thousands, and whether their beliefs are centered on a single text or many, religions share certain core features:

Religious systems protect and transmit the means through which life can be fulfilled. Some of these goals are proximate, having to do with how to live a wiser, more fruitful, more charitable, or more successful life; others are ultimate, and have to do with the fate not only of human beings but of the cosmos itself. In the latter case, they often include a judgment after death.