《旧唐书·列传·卷五十二》
史才还要应是正直，善恶都写，使骄主贼臣，因此知道害怕，这就如虎添翼，善无可加，所向无敌了。
犹须好是正直，善恶必书，使骄主贼臣，所以知惧，此则为虎傅翼，善无可知，所向无敌者矣。
A historian should be honest and impartial, recording both good and evil, so that proud and depraved rulers and ministers would be afraid. This would be like adding wings to a tiger, and there would be no room for improvement or defeat.