《孔子家语·哀公问政》
想要修身，不能不侍奉父母；要侍奉父母，不能不了解人；要了解人，不能不知天。天下共通的人伦大道有五条，用来实行这五条人伦大道的德行有三种。
是以君子不可以不修身；思修身，不可以不事亲；思事亲，不可以不知人；思知人，不可以不知天。天下之达道有五，其所以行之者三。
If one wants to develop himself, one must serve one’s parents; if one wants to serve one’s parents, one must understand people; if one wants to understand people, one must know the heavens. There are five universal human social principles in this world; there are three moral virtues used to carry out these five principles.