大義滅親

Etymology
From . Zhou Yu (州吁) had murdered his brother, Duke Huan of Wey (衛桓公), and taken his place. But he could not gain the favor of the people of Wey. Shi Que (石碏), an officer loyal to the state, devised a scheme and had the usurper killed. Shi Que's son Shi Hou was a close associate of Zhou Yu, so Shi Que had his son killed as well. The people praised his act (《左傳·隱公四年》):



Idiom

 * 1) to place righteousness before family​; to be ready to punish one's own family if justice demands it