When did I start to be divided into three schools?

During the Spring and Autumn Period, with the rise of private schools, Yi-ology began to divide into three schools, namely:

Zhouyi: The Book of Changes is the core of the Book of Changes and the earliest version of the Book of Changes. Its main content is the interpretation and application of eight diagrams and sixty-four hexagrams. The Zhouyi school mainly pays attention to the philosophical thought and spiritual connotation of the Book of Changes.

Ji Yi: Ji Yi was developed on the basis of the Book of Changes, and mainly used the divination prediction of the Book of Changes, including Yin and Yang, five elements, eight diagrams, sixty-four hexagrams and other divination methods.

Yi Zhuan: Yi Zhuan is a school that mainly teaches the Book of Changes, paying attention to the inheritance and interpretation of the contents of the Book of Changes, including the text research, interpretation and annotation of the Book of Changes.

In the later development, these three schools gradually formed different schools and schools, such as Zhouyi of Taoism, Jiyi of Confucianism, and Yi Chuan of Yangming Studies. Yi-ology occupies an important position in the cultural history of China, and has a far-reaching influence on China's philosophy, culture and thoughts.