Thus the philosophical roots of this school also lie with the classical Greek philosophers who argued that humans had a natural potential, or telos, and that the good life was a life-spent developing or fulfilling that telos. This general approach is called a teleological ethics, and it is a tradition that was carried on through the great Christian philosophers of the medieval period. The contem¬porary slogan of the U.S. Army to "Be all that you can be" reflects the same eth¬ical attitude. Humans have a potential that they don't always fulfill; the good life is a life in which this potential is actualized. The human fulfillment school believes that work can be the process through which this potential is fulfilled.