The Buddha (563–483 B.C.E.) believed in the karmic laws that gripped and held those who did not understand the true nature of life and death. But because the universe and reality are always in a state of flux, forever changing and reshaping themselves, there can be no single, unique soul of any individual that is caught up in the cycle of death and rebirth. The various components that make up a human being are in a perpetual process of change but always
held by the laws of karma, which determine the nature of a person's rebirth.
There are many schools of Buddhism, and certain scholars point out that the so-called "Northern Buddhism" of Tibet, China, and Japan, emphasizes the doctrine of a permanent identity which serves to unite all the incarnations of a single individual. Such an emphasis is closer to the Hindu interpretation of a continuity of a soul linked to its karma than the strict Buddhist teaching that only psychic residues remain of an individual's traits of personality and character. As might be expected, Northern Buddhism claims to have preserved the true teaching given by the Buddha to his initiated disciples. Since karma is one of the key teachings of the Buddha, they insist that the concept becomes virtually meaningless unless it is applied to the idea of a single reincarnating ego. The teachers of Northern Buddhism also recall that according to tradition, the Buddha's dying words were: "All compounds are perishable. Spirit is the sole, elementary, and primordial unity, and each of its rays is immortal, infinite, and indestructible. Beware of the illusions of matter."