The essence of the preface to Shuo Wen Jie Zi is to interpret the main content of the preface as a short answer.

First of all, Xu Shen studied the background of Chinese characters: "The ancients loved the king of the family, and all kinds of products were available." Before the emergence of Chinese characters, there were eight diagrams, knots, lettering and other notation systems, which were not words, but had similar note-taking functions to words. The generation of words has a better effect for the same purpose. Xu Shen also studied the creation process of Chinese characters: "

Secondly, Xu Shen studied the development history of Chinese characters. He believes that the Chinese characters made in Cang Xie are pictographs, and then the fonts changed constantly during the Five Emperors and Three Kings. Zhou Xuanwang Taishigong wrote "Da Zhuan" 15, which may be different from Cang Xie ancient prose. During the Warring States period, different languages were spoken in different places, and the characters were deformed. Qin Shihuang unified the world with Xiao Zhuan. At this time, due to the complexity of official prisons, simple official documents began to appear.

Most importantly, Xu Shen studied the structure of Chinese characters. From Zhou Li's "Six Books" to Ban Gu's "Records of Han Shu Literature and Art", it has been made clear that six books are Chinese characters. It was not until Xu Shen systematically explained the Six Books: "Li Zhou entered primary school at the age of eight, ..., and was also the commander in chief." Since then, Liushu has become a systematic theory of Chinese word formation.

Extracted from Nankai University Documentary Notes, typed word for word for adoption.