過猶不及（過猶不及）　

◎ 過猶不及 guòyóubùjí

(1) [going too far is as bad as not going far enough] 做事做過了頭,就如同做的不夠一樣。指做事以適當(dāng)為貴

子貢問:“ 師與 商也孰賢?”子曰:“師也過,商也不及。”曰:“然則 師愈與?”曰:“過猶不及。”——《論語·先進(jìn)》

(2) (師,指子張;商,指子夏;愈:較好)