The Four Books, also known as the Four Books, are the collective names of The Analects of Confucius, Mencius, Daxue and The Doctrine of the Mean, and are the core books learned by Confucian scholars in past dynasties. Zhu, a philosopher in the Southern Song Dynasty, selected two chapters from The Doctrine of the Mean and The Great Learning for annotation, and combined them with The Analects of Confucius and Mencius into four books.