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The Doctrine of the Mean is a monograph of China's ancient moral philosophy on the realm of life accomplishment, and it is one of the Confucian classics. Originally belonging to Chapter 31 of the Book of Rites, it is said that it was written by Zi Si during the Warring States Period. Its content affirms that "the doctrine of the mean" is the highest standard of moral behavior, and "honesty" reaches the highest level of life, and puts forward the learning process and cognitive method of "erudition, interrogation, careful thinking, discernment and loyalty". Song scholars extracted the doctrine of the mean from the Book of Rites, and called it "four books" with Daxue, Analects of Confucius and Mencius.
The author of The Book of Songs is anonymous, and most of them cannot be verified. They were collected by Yin Jifu and edited by Confucius. In the pre-Qin period, the Book of Songs was called "The Book of Songs", or it was called "The Book of Songs 300" by integers. In the Western Han Dynasty, it was honored as a Confucian classic, formerly known as The Book of Songs, which has been in use ever since. The Book of Songs is divided into three parts: style, elegance and ode. Techniques are divided into Fu, Bi and Xing. "Wind" is a ballad of Zhou Dynasty. Elegant music is the official music of Zhou people, which is divided into harmony and elegance. Ode is a music song used for sacrificial rites in Zhou and aristocratic ancestral temples, which is divided into, and Shang songs.