It is quite true that man lives by bread alone—where there is no bread. But what happens to man’s desires when there is plenty of bread and when his belly is chronically filled? At once other (and “higher”) needs emerge and these, rather than physiological hungers, dominate the organism. And when these in turn are satisfied, again new (and still “higher”) needs emerge, and so on. That is what we mean by saying that the basic human needs are organized into a hierarchy of relative prepotency.—Abraham Maslow (1943)

Courtesy of Robert D. Farber University Archives at Brandeis University