The collective name of "The Great Learning", "The Doctrine of the Mean", "The Analects" and "Mencius". In the Song Dynasty, people took out the two chapters of "The Great Learning" and "The Doctrine of the Mean" from "The Book of Rites", and combined them with "The Analects" and "Mencius". During the Chunxi period of the Southern Song Dynasty, Zhu Xi wrote the "Collected Annotations of the Four Books", thus finalizing the name of the "Four Books". Since then, the "Four Books" have always been the essential reading materials for orthodox education in feudal society and the primary standard texts for the imperial examinations.