1) Focus on the past and confuse the false with the true.
Make the past serve the present, and superstition of sages has existed since ancient times. In order to publicize their theories, some people adopt Togu's method. For example, Confucianism relies on Yao and Shun, while Taoism traces the Yellow Emperor. This ethos was quite popular in the Warring States, Qin and Han Dynasties, and then there appeared legends about the creation of ancient books, such as Fu's Yi Gua and Huangdi Neijing. Liu Xiang and his son collated the books of the Western Han Dynasty. It was pointed out that most of these legendary books were actually forged by people in the Warring States period. Nevertheless, this custom had a great influence on the academic thought of later generations.
2) Forgery for political purposes
From the late Western Han Dynasty to the early Eastern Han Dynasty, a series of divination books suddenly appeared in the society. The Annals of Sui Shu's Classics reveals that the study of divination began with Wang Mang. In order to usurp the Han dynasty, he forged divination and used it as a tool of public opinion, thus opening the end of divination. Sometimes political groups with different interests fight and use fake books to achieve their political goals. For example, in the "Party struggle between Niu and Li", Master Li Deyu used the name of Niu and Monk to fabricate "Qin Zhou" to frame Niu and Ru, so as to achieve the purpose of attacking political enemies.
3) Cheating for academic success.
In order to maintain the school's theory, forging ancient books is one of its important means. For example, at the end of the Eastern Han Dynasty, Zheng Xuan was a master of Confucian classics. During the Cao Wei period, Wang Su wanted to be exclusive and opposed, and he did not hesitate to forge ancient books. Confucius' family story is the most representative. In order to compete with Buddhism, Taoism forged many works, such as Hu Jing by Laozi.
4) Forgery for reputation or economic benefit.
Falsification is also a means for individual scholars to seek fame and reputation. When Emperor Wendi of Sui asked for a suicide note, the literati forged Lian and other books one after another and handed them over to the court for reward. After the invention and popularization of rigid printing, publishing books has become a job that can bring huge profits, and engraving books for profit has become a means for some booksellers to make money.
5) unintentional forgery
In the process of long-term communication and writing, characters have undergone various changes in nature. If the author's records are corrupted and future generations lack the necessary investigation, the author's title is inaccurate and belongs to unintentional forgery. In addition, people think that ancient books must have authors. If there is no signature, the author will be questioned according to the contents recorded in the book, which makes the book a fake. For example, Zhousuanjing thinks that Duke Zhou is the author of the book.