In
ontology and the
philosophy of mind, a
non-physical entity is a spirit or being that exists outside of physical reality. Their existence divides the philosophical school of
physicalism from the schools of
idealism and
dualism; with the latter schools holding that they can exist and the former holding that they cannot. If one posits that non-physical entities can exist, there exist further debates as to their inherent natures and their position relative to physical entities.