The principle of founding the country mentioned here, that is, the corresponding principle of etiquette and music system, is "the big one will eventually be small."
This sentence comes from "Zuo Zhuan Huan Gong Two Years", and the following text is: "Therefore, the son of heaven founded the country, the princes established the clan, and the nobles established the side room. There are two doctors and children of scholars. Shu Ren, industry and commerce all have their own relatives, and they all have the same decline. Serve the people, not covet them. Jin, the back of the temple, and the founding of the country. This is weak, how long can it last? " It means: "So the emperor founded the country, the princes established the clan, and the Qing Dynasty established the side room (the following" two cases "are all sons other than children), doctors have two cases, scholars have subordinate children, and ordinary people, craftsmen, businessmen and relatives have their own branches, which gradually decrease according to the level. In this way, ordinary people can obey and serve their superiors, while people at lower levels will not spy on their superiors. Now Jin is just a vassal less than a thousand miles away from the city, and even established a country. It is weak at all, can it last? "
Judging from this passage, the system of rites and music at that time was based on the gradually decreasing enfeoffment system: emperor-vassal-Qing-doctor-scholar-Shu Ren. Except for the heir who retains the original title, all other sons have to be demoted to one level, and each level enjoys the corresponding etiquette and music treatment, which cannot be exceeded. In this way, the royal family has the power to rule the world, and the most powerful one is like the strong root of a tree. Governors, ministers, doctors, scholars and Shu Ren are like branches and leaves of a tree. They are more and more scattered and weaker, and the world is stable. If a branch exceeds the trunk, it will inevitably produce rebellious thoughts and disobey the orders of superiors. Therefore, after the Spring and Autumn Period, the Emperor of Zhou was shelved, and the princes scuffled and merged with each other, resulting in what Confucius called "the ritual collapsed and the music was bad".