Greeks upheld the ideal of sophrosyne, which means prudence and moderation but ultimately its complex meaning, so important to the ancients, is very difficult to convey in English. It is perhaps best expressed by the two most famous sayings of the oracle at Delphi: "Nothing in excess" and "Know thyself."
The term suggests a life-long happiness obtained when one's philosophical needs are satisfied, resembling the idea of enlightenment through harmonious living. It is a nearly lost Classical ideal, but is enjoying some revival today with its emphasis on individuals to live within the proportions of reason and nature, this being achieved through practical wisdom and self knowledge. Parallels abound in eastern thought, in Hinduism, Buddhism and Taoism.
The word is found in the writings of Ancient Greece, especially that of Plato in ethical discussions of the dialogue Charmides where it refers to the avoidance of excess in daily life. This term in Plato's use is connected with the Pythagorean idea of harmonia.
In Christian theology, especially in the Greek Orthodox patristic form, the word sophrosyne has come to mean purity, integrity and virginity.
Hypatia of Alexandria was regarded as an example of sophrosyne. Biographer Marie Dzielsky states that Hypatia remained a virgin to the end of her life
Examples of this term often appear in Greek literature as well. See the character of Deianeira in Trachinian Women by Sophocles. Achilles in The Iliad when Agamemnon decides to take Briseis or Oedipus in Oedipus Rex are examples of characters without sophrosyne. Plato's Symposium could accurately be subtitled "On Sophrosyne," and his character Socrates is sophrosyne exemplified.