Yin-Yang School

The Yin-Yang School (Yinyangjia) is a current of ancient Chinese cosmological philosophy associated chiefly with the statesman and thinker Zou Yan, who systematized the complementary forces of yin and yang together with the theory of the Five Phases (wuxing: wood, fire, earth, metal and water) into a comprehensive account of cosmic, seasonal and historical change. The school held that natural, political and even dynastic events follow cyclical patterns governed by the alternation and mutual generation or conquest of the Five Phases, and Zou Yan applied this framework to argue that each ruling dynasty corresponded to a particular phase whose eventual supersession by the next explained and legitimated dynastic succession. Rather than remaining an independent school with its own transmitted texts and disciples in the way Confucianism or Mohism did, Yin-Yang cosmology was rapidly absorbed into the intellectual mainstream of Han-dynasty China, merging with Confucian ritual theory, Daoist cosmology and early Chinese medicine. Its categories of yin-yang and the Five Phases became a permanent, largely school-independent grammar of Chinese thought, still visible today in traditional medicine, divination and calendrical practice long after the Yin-Yang School itself ceased to exist as a distinct lineage.