Moderate

"The Doctrine of the Mean" is a moral philosophy monograph in ancient China that discusses the realm of life cultivation. It originally belonged to Chapter 31 of the "Book of Rites" and is one of the Confucian classics. It is said to have been written by Zisi during the Warring States Period. Its content affirms that "moderate" is the highest standard of moral behavior, regards "sincerity" as the ontology of the world, and believes that "perfect sincerity" reaches the highest realm of life. It also proposes a learning process and understanding method of "learning extensively, interrogating, thinking carefully, discerning clearly, and practicing sincerely". Scholars in the Song Dynasty extracted "The Doctrine of the Mean" from the "Book of Rites" and combined it with "The Great Learning", "The Analects of Confucius" and "Mencius" into the "Four Books". After the Song and Yuan Dynasties, it became an official school textbook and a required reading for imperial examinations, which had a great impact on ancient Chinese education and society. Its main annotations include Cheng Hao's "The Doctrine of the Mean", Cheng Yi's "The Doctrine of the Doctrine", Zhu Xi's "The Doctrine of the Mean", Li Kuan's "The Doctrine of the Mean", Dai Zhen's "Supplementary Notes on the Doctrine of the Mean", Kang Youwei's "The Doctrine of the Mean", Ma Qichang's "The Doctrine of the Doctrine" and Hu Huaichen's "A Brief Theory of the Doctrine", etc.