 An individual organic life requires an internal source of motion, or “soul”, which resides in the material body from the outset. This soul guides the gradual epigenetic process of development. This is the Aristotelian and not the Christian soul. Soul consists of the vegetative (for all organisms), locomotory (for animals), and rational (for humans). The soul, consisting of one to three parts depending on the kind of living being, resides in the combination of male and female semen. The living differs from the dead because of the action of the soul. Therefore, it is the teleological drive of the potential that actualizes the individual and its form and function, epigenetically, gradually, and internally.