This involves a very important issue in China culture, that is, the "Debate on Foreign Countries and Summer". Judging from its origin, the word "Yidi" refers to ethnic groups outside the Central Plains. But in the Spring and Autumn Annals compiled by Confucius, it does not refer to these remote ethnic groups, but a moral and cultural term. In other words, the place with low level of moral etiquette is called "Yidi", and the place with high level of moral etiquette is called "Zhu Xia" or "Huaxia". If there is moral etiquette in the Central Plains, then this nation is an excellent one, even if it has no king, it is also excellent; If there is no moral etiquette, then this nation is not an excellent nation, even if there is a king, there is nothing to recommend it. Morality, propriety and righteousness are more important than kings. In the "Three Generations Theory" of Confucius, the one with a low degree of social civilization is "following the troubled times", and the level of moral etiquette is not high; The "Shengpingshi" with a higher degree of civilization has a higher level of moral etiquette; The highest state of civilization is "great harmony", the highest state of morality and propriety. The revival of Chinese culture is to establish such a "great harmony" society.