culture
Asked by Taizong what makes a ruler clear-sighted or blind, he answered 兼听则明，偏信则暗: 'listen to all sides and you see clearly; believe one side and you are in the dark'. It is now an everyday saying for hearing both sides out.
history
He first served Taizong's elder brother and rival 李建成, and urged him to strike first against the future emperor. After seizing power, Taizong spared him and made him an adviser. The name is also written 魏徵, its traditional form.
