Neo-Confucianism describes itself with names its own tradition preferred, Daoxue, the learning of the Way, and Lixue, the learning of principle, marking how differently its adherents understood the project from a simple return to Confucius and Mencius. Zhou Dunyi (1017 to 1073) opened the program with a diagram and treatise on the Supreme Ultimate that gave Confucian ethics a cosmological account connecting the moral order of human life to the physical order of the universe, a question the Analects had never posed. The brothers Cheng Hao and Cheng Yi developed li, principle, as the pattern inherent in each thing, waiting to be investigated rather than simply obeyed.
Zhu Xi, working from 1130 to 1200, brought these threads into the synthesis later dynasties adopted as orthodoxy, pairing li with qi, the vital stuff concrete things are made of, and arguing that moral cultivation means investigating things, ge wu, to recover the principle each person already possesses but obscures through impure qi. His commentary on the Four Books became the official basis of the civil service examinations in 1313, giving one interpreter's reading of classical Confucianism the force of state orthodoxy for centuries.
A later branch under Wang Yangming (1472 to 1529) rejected Zhu Xi's emphasis on investigating external things and argued instead for liangzhi, an innate capacity for moral knowledge already complete in the mind, needing only to be acted on. What separates this from the Confucianism of Confucius and Mencius is not a change of ethical conclusion so much as a metaphysical apparatus, built partly in conversation with Buddhist and Daoist ideas the classical texts never engaged, layered beneath ethics that read, on their surface, as continuous with the earliest tradition.