The ancient people believed in the concept of "divine right of monarchy" and thought that who was the emperor was given by God. In fact, this is a lie made up by the rules to maintain their own rule. During the Warring States Period, a hundred schools of thought contended, and there were teachers of Yin and Yang. Zou Yan, the founder, synthesized the previous research results of Yin-Yang and Five Elements, taking Shangshu as an example. 6? Based on 1 Hong Fan, he developed a set of theory of "Five Virtues at the End", that is to say, the basic elements of the world are the five elements of gold, wood, water, fire and earth, and everything in the world comes from the complex relationship of mutual generation and mutual resistance. The rise and fall of dynasties actually followed the law of the replacement of the five elements. Every dynasty has its virtues, just as everyone has a zodiac. Deco is a virtue, so one dynasty replaced another. This kind of regime change is called "five elements win each other". Zhang Jiao knows witchcraft very well. Perhaps he has heard of the theory of "five virtues begin at the end". According to this theory, "Cang" can be regarded as "water color", which belongs to "water virtue" and yellow belongs to "earth virtue", and soil can overcome water. Then "Huangtian" replaces "Cangtian" and naturally succeeds.