Zhu (1 130- 1200), a philosopher in the Southern Song Dynasty, was born in Wuyuan, Jiangxi. 18-year-old Jinshi, editor of the Privy Council. In philosophy, he developed the theories of Cheng Yi and Cheng Hao and became a master of Neo-Confucianism. He wrote many academic works, and later generations compiled a complete collection of Zhu Xi. Zhu advocated the restoration of three generations of rule, and the road of hope will last forever. He put forward the idea of "keeping justice in nature and destroying human desires", emphasizing "keeping the heart upright, cultivating oneself, keeping the family in order, governing the country and securing the world". In his article "A Letter with Liu Zicheng", he said this: "The sage opened eight characters, but people did not understand, but went crazy." The meaning of this passage is that the door of saints has long been opened, but people have ignored it. They didn't go in, but went out. Although the theme of this sentence is to let people learn the way of sages, it shows Zhu's regret, regret and helplessness for those who don't recognize the door. However, he would never have thought that this sentence turned out to be the source of this sentence. The problem lies in his "eight", just like two doors. Zhu used eight metaphors here, which are undoubtedly very vivid. If you don't leave the word "eight characters", there is no way. At present, we often say "no way" (meaning impossible) and "no way to go" (meaning no way to go), if traced back to the source, I'm afraid both come from this. Like anything in the world, proverbs are developing and their meanings are changing. The original meaning of "there is no road in eight characters" has now evolved into a synonym for no road, no clue, no clue and no connection.