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.
The soul has been the central area of interest in philosophy since ancient times. Socrates envisioned the soul to possess a rational faculty, its practice being man's most godlike activity. Plato believed the soul to be the person's real self, an immaterial and immortal dweller of our lives that continues and thinks even after death. Aristotle sketched out the soul as the "first actuality" of a naturally organized body—form and matter arrangement allowing natural beings to aspire to full actualization.