The word for ‘soul’ in Aristotle is psuche. In Latin it is translated as anima. For many readers, it is the use of the Latin term (particularly as it was used by Christian, Moslem, and Jewish theologians) that forms the basis of our modern understanding of the word. Under the theological tradition, the soul meant an immaterial, detached ruling power within a human. It was immortal and went to God after death. This tradition gave rise to Descartes’ metaphysical dualism: the doctrine that there are two sorts of things that exist (soul and matter), and that soul ruled matter.