The soul is the purported immaterial aspect or essence of a living being. It is typically believed to be immortal and to exist apart from the material world. The three main theories that describe the relationship between the soul and the body are interactionism, parallelism, and epiphenomenalism. Anthropologists and psychologists have found that most humans are naturally inclined to believe in the existence of the soul and that they have interculturally distinguished between souls and bodies.