Religion is a class of human practices and ideas. Its paradigmatic examples are Judaism, Christianity, Islam, Hinduism, Buddhism, and Confucianism. In addition, there are religions that cannot be identified by name but which are common to a region or group of people. These are often called folk or popular religions.
A key characteristic of religion is a supernatural dimension that separates it from philosophical or purely ethical systems. The supernatural dimension involves a recognition of dependence on the invisible world that stirs the imagination, engages the emotions, and provokes hope. It also calls into play the concept of a personal deity that has promised to provide protection and fulfillment in this life or in the next.
It is believed that the religious dimension emerges out of human curiosity about the unknown and fear of uncontrollable forces. It transforms this curiosity and fear into a desire for immortality or reincarnation, for a compassionate creator who watches over humanity, and for a meaning to life.
The study of religion on a cross-cultural basis first appeared as an academic discipline in the nineteenth century with the work of Max Muller and the Dutch theologians Pierre Daniel Chantepie de la Saussaye and Cornelis Petrus Tiele. Efforts to place comparative methodology on a solid scientific basis continued throughout the twentieth century. One of these attempts was made by Rodney Needham, who developed a system for sorting different social phenomena according to their properties. Treating them as a class in this way allows the discovery of patterns and the co-appearance of certain characteristics, which in turn can lead to explanatory theories.