After studying the "Yi", the former teacher Confucius once made an evaluation of the "Yi": "The Jingjing Jingwei is the teaching of the Yi." So, what does this sentence mean? "Jie Jing" means that "Yi" is a very simple and quiet book, and its thoughts and content are also very simple. It only reveals the simplest principles. Laozi also said in "Tao De Jing" He said: "The beginning of all things, the great road is simple, and the evolution is complex." "Yi" is elaborating on this simple truth, and uses these simple truths to reveal the complicated things in reality; and its tranquility is because these are the most simple truths. Simple truths are eternal, so the ideas of "Yi" are actually applicable at all times. Only in this way can we cope with the ever-changing changes with unchanging principles and reveal complex truths with simple principles.

The "subtle" means that although "Yi" has simple principles, it is very precise, rigorous and mysterious. Its details are the symbol Bagua and its evolved sixty-four hexagrams in the Book of Changes, which reveal that everything in the universe, no matter how big or small, is included in it. The mystery is that many people cannot understand the simplest truth in the world. It is very profound. The first teacher Confucius only had a certain understanding of Yi after he was fifty years old.

Three Yis

The "Zhouyi" we are studying now is actually only a part of our country's Yi study, that is, the "Zhouyi". However, there are actually other Yis in ancient my country, one is called "Lianshan" and the other is called "Guizang". According to legend, "Lian Shan" was written by the first emperor of Pangu after the creation of the world. "Lianshan" starts with the hexagram Gen and extends to the mountains, so it is named Lianshan. However, Mr. Nan Huaijin once said that it was actually a Yi made during the Shennong era. After all, the creation of Pangu is a myth and legend, and the name of the Emperor's family is even more unknown. Some people say that it is actually Yi from the Xia Dynasty, but this is just speculation.