Tsou Yen (350?–270? B.C.), Chinese cosmologist, a member of the Chi-hsia Academy and influential political figure who applied yin–yang fivephases thinking to dynastic cycles. Tsou Yen believed that the natural order, the human order, and the relation between the two were all governed and made intelligible by the dynamic interplay among yin–yang and the five phases (wu-hsing: earth, wood, metal, fire, and water). He gained political fame for his idea that the rise and fall of dynasties are correlated with the five phases and accord with the same cyclical pattern: earth, wood, metal, fire, and water. Thus, the reign of the Yellow Emperor, correlated with the earth phase, was followed by the Hsia (wood), the Shang (metal), and the Chou (fire) dynasties. Tsou Yen predicted that the ascendancy of the water phase would signal the end of the Chou and the beginning of a new dynasty. See also CHINESE PHILOSOPHY. R.P.P. & R.T.A.