Arete

"Arete (Greek: ἀρετή, pronounced in English [ˈærəteɪ] or "ar-uh-tay") in its basic sense means "goodness" or "excellence" of any kind. In its earliest appearance in Greek this notion of excellence was bound up with the notion of the fulfillment of purpose or function; the act of living up to one's full potential. It is essentially being and doing one's absolute best - becoming the best person one can be. The moral excellence or arete of a person or thing was then ηθικη, αρετη or virtue. Alexander the Great was said to exemplify arete in his steadfast pursuit of excellence[citation needed].
"The root of the word is the same as 'aristos', the word which shows superlative ability and superiority, and 'aristos' was constantly used in the plural to denote the nobility." [1] (see Aristocracy) The Ancient Greeks applied the term to anything: for example, the excellence of a chimney, the excellence of a bull to be bred, and the excellence of a man. The meaning of the word changes depending on what it describes, since everything has its own particular excellence; the arete of a man is different from the arete of a horse. This way of thinking first comes from Plato, and can be seen in Plato's Allegory of the Cave. This can be read at the following link.[2].
By the fourth and fifth centuries B.C.E., arete as applied to men had developed to include quieter virtues, such as dikaiosyne (justice) and sophrosyne (self-restraint). Plato attempted to produce a moral philosophy that incorporated this new usage (and in doing so developed ideas that played a central part in later Christian thought), but it was in the work of Aristotle that the doctrine of arete found its fullest flowering. Arisotle's "Doctrine of the Mean" (not to be confused with Confucious's Doctrine of the Mean) and "The Four Causes" are good examples of Aristotle's thinking." From Wikipedia