sophrosyne

[suh-fros-uh-nee] /səˈfrɒs ə ni/
noun
1.
moderation; discretion; prudence.
Compare hubris.
Origin
< Greek sōphrosýnē, derivative of sṓphrōn prudent
Word Origin and History for sophrosyne
n.

the quality of wise moderation; Greek, "prudence, moderation in desires, discretion, temperance," from sophron "of sound mind, prudent, temperate" (see Sophronia).