This article is about the Greek virtue. For the asteroid, see 134 Sophrosyne.
Sophrosyne (Greek: σωφροσύνη) is an ancient Greek concept of an ideal of excellence of character and soundness of mind, which when combined in one well-balanced individual leads to other qualities, such as temperance, moderation, prudence, purity, decorum and self-control.
In Greek literature sophrosyne is considered an important quality, and is sometimes expressed in opposition to the concept of hubris. A noted example of this occurs in Homer's The Iliad. When Agamemnon decides to take the queen, Briseis, away from Achilles, it is seen as Agamemnon behaving with hubris and lacking sophrosyne.
In Homer's Odyssey, Odysseus avoids being turned by Circe the enchantress into an animal by means of a magical herb, moly (symbolizing, by some accounts, sophrosyne), given to him by Athena (Wisdom) and Hermes (Reason).:127
Heraclitus's fragment 112 states: "Sophrosyne is the greatest virtue, and wisdom is speaking and acting the truth, paying heed to the nature of things." (σωφρονεῖν ἀρετὴ μεγίστη, καὶ σοφίη ἀληθέα λέγειν καὶ ποιεῖν κατὰ φύσιν ἐπαίοντας.)
Themes connected with sophrosyne and hubris figure prominently in plays of Aeschylus, Sophocles and Euripides; sophrosyne is recognized as a virtue, although debased forms like prudery are criticized.
 Sophrosyne is a theme in the play Hippolytus by Euripides, where sophrosyne is represented by the goddess Artemis and is personified by the character Hippolytus.
Hope is the only good god remaining among mankind;
the others have left and gone to Olympus. Trust, a mighty god has gone, Restraint (Sophrosyne) has gone from men,
and the Graces, my friend, have abandoned the earth.
The De Astronomica lists Continentia among the daughters of Erebus and Nyx, who is thought to be the Roman equivalent of Sophrosyne.
Sophrosyne is an important topic for Plato. It is the main subject of the dialogue Charmides, wherein several definitions are proposed but no conclusion reached; however the dramatic context connotes moral purity and innocence. An etymological meaning of sophrosyne as "moral sanity" is proposed in Cratylus 411e. Plato's view of sophrosyne is related to Pythagorean harmonia (Republic 430e−432a, 442c) and closely linked with Plato’s
tripartite division of the soul: sophrosyne is the harmonious moderation of the appetitive and spirited parts of the soul by the rational part (e.g., Phaedrus 237c−238e).
Demophilus, a Pythagorean philosopher of uncertain date, wrote: "The vigor of the soul is sophrosyne, the light of a soul free of disturbing passions." (Ρώμη ψυχής σωφροσύνη αύτη γαρ ψυχής απαθούς φώς εστιν.)
Cicero considered four Latin terms to translate sophrosyne: temperantia (temperance), moderatio (moderateness), modestia (modesty) and frugalitas (frugality). Through the writings of Lactantius, St. Ambrose and St. Augustine, the virtue's meaning as temperance or "proper mixture" became the dominant view in subsequent Western European thought.:29