Pin Shijing
All three kings must teach the crown prince with rituals and music. Music is used to cultivate the inner self; rites are used to cultivate the outer self. Rites and music interweave within and manifest themselves in the outer self. Therefore, the result is joy, respect, and gentleness. The establishment of a great tutor and a junior tutor to raise the child is to make him know the way of father and son, and the way of the ruler and his subjects. The great tutor examines the way of father and son, and the way of the ruler and his subjects and shows it to him; the junior tutor serves the crown prince to observe the virtues of the great tutor and to teach him. The great tutor is in front, and the junior tutor is in the back; when entering, there is a guardian, and when leaving, there is a teacher. This is how virtue is cultivated through teaching and teaching. A teacher is one who teaches and teaches virtues through things; a guardian is one who is careful in his own conduct to assist and guide him and return to the way. The Records says: "In the Yu, Xia, Shang, and Zhou dynasties, there were teachers and guardians, and there were ministers." Four assistants and three dukes were set up. They were not necessarily appointed, but only the right people were appointed. It is said that the gentleman is capable. When virtue is established, teaching is respected, teaching is respected, and officials are upright, and officials are upright, and the country is governed. This is what a monarch is. Zhongni said: "In the past, when the Duke of Zhou was regent, he took the throne and ruled. He followed the example of Boqin, so that he could help King Cheng. I heard that: If a minister sacrifices his own life to benefit the monarch, he will do it. How much more so, if he sacrifices his own life to benefit the monarch? The Duke of Zhou did it well!" Therefore, only when you know how to be a son can you be a father; only when you know how to be a minister can you be a monarch; only when you know how to serve people can you lead people. King Cheng was young and could not take the throne. If he was the crown prince, he would not be able to do anything. Therefore, the crown prince followed the example of Boqin and made him live with King Cheng, so that King Cheng would know the righteousness of father and son, monarch and minister, and elder and younger. The monarch is close to the crown prince as a father and respects him as a monarch. Only when you have the closeness of a father and the respect of a monarch can you control the world. Therefore, you must be careful when raising the crown prince. The only one who can achieve three good things by doing one thing is the crown prince. This is what it means to be a good scholar. Therefore, when the crown prince is in school, the people of the country look at it and ask: "Why do you give me the throne and let me have the same age?" He said: "When the father is around, it is polite, but everyone knows the way of father and son." The second question is: "Why do you give me the throne and let me have the same age?" He said: "When the king is around, it is polite, but everyone is obsessed with the righteousness of the king and the minister." The third question is: "Why do you give me the throne and let me have the same age?" He said: "The elder is the elder, but everyone knows the distinction between the elder and the younger." Therefore, when the father is here, he is the son, and when the king is here, he is the minister. The distinction between son and minister is to respect the king and love relatives. Therefore, learn to be a father and son, learn to be a king and a minister, learn to be the elder and the younger. The way of father and son, king and minister, and the elder and the younger is obtained, and the country is governed. There is a saying: "The music is in charge of the industry, the father and the teacher are in charge of the completion. If there is a good person, all nations will be loyal." This is what the crown prince means. Duke Zhou ascended the throne.
