Golden mean (philosophy)

The golden mean or golden middle way is the desirable middle between two extremes, one of excess and the other of deficiency. It appeared in Greek thought at least as early as the Delphic maxim "nothing in excess" and emphasized in later Aristotelian philosophy.[1]

For example, in the Aristotelian view, courage is a virtue, but if taken to excess would manifest as recklessness, and, in deficiency, cowardice.