《新唐书·列传·卷二十二》
魏徵说： 君主之所以明，在于多方听取意见；之所以暗，在于偏听偏信。
徵曰： 君所以明，兼听也；所以暗，偏信也。
Wei Zheng replied: “A ruler is wise because he listens to opinions from all sides, and he is foolish because he only listens to one side of the story.” 