The Book of Changes begins with the Book of Changes. The Book of Changes is the earliest classic of China. It is a complete system composed of symbol system and writing system, and the symbol system should be formed before the writing system, that is to say, before Chinese characters appeared, there was the symbol system of Yijing.
The Book of Changes comes from people's demand for predicting the quality of actions, and it is a manifestation of people's purposeful activities. The purpose of people's actions is one of the signs that people are different from animals. That is to say, since a person is a person, his behavior has a purpose, that is, he must predict the quality of his behavior before he acts. The Book of Changes is a forecasting system formed in the practice of forecasting good and bad luck in ancient China. This prediction system consists of two symbols: Yin-Yang, Eight Diagrams and Sixty-four Guas. Each symbol has six Guas and 384 Guas, which constitutes a complete symbol system. In the long-term prediction practice, the hit rate of divination is constantly summarized, and the writing system of divination words is formed. The Book of Changes is unique not only in China, but also in the world.
The Book of Changes was originally used to predict good or bad luck, so Lei Yu of Zhu said: "The Book of Changes is a kind of divination book, which was hidden by the ancients in Taishitai Department to predict good or bad luck." Zhouyi is a book of divination, but it contains moral content. Therefore, Confucius attached great importance to the Book of Changes. He once said: "Add me a few years old, and I can learn the Book of Changes at the age of 50, which is not bad" (The Analects of Shu II). According to the latest archaeological excavations, the relationship between Confucius and Yi is recorded in the silk book Yi, such as Ersan, Zhiyi and Yao Yao. The silk book Yao says: "Confucius is old and easy, staying at the table and walking in the bag", which is the same as the saying in Historical Records of Confucius Family that Confucius likes to be late. When Confucius' disciples questioned Confucius' love for Yi in his later years: "Why is Confucius old and good?" Confucius pointed out in his reply: "I have the ear of benevolence and righteousness", which shows that Confucius studied the Book of Changes from the aspect of benevolence and righteousness. According to legend, the moral thought in Yi Zhuan, written for Confucius, is the inheritance and development of righteousness and virtue.
The Book of Changes contains not only moral contents, but also profound philosophical thoughts. Laozi, the founder of Taoism, revealed the philosophical connotation of Zhouyi from Yi Dao and made a new development of Zhouyi.
Thus, the development of Zhouyi is from Yijing to Yi De and Yi Dao.