THE CHINESE have enjoyed the reputation of being an almost uniquely historical-minded people. Perhaps the most impressive evidence in support of this generalization is to be found in the group of two dozen official dynastic histories. Lined up side by side on library shelves, they not only testify to the systematic interest of the Chinese in their past but symbolize the pattern in terms of which the Chinese have seen that past. Traditionally, the history of China has been written as a long series of dynastic periods. Each dynasty maintained a board to keep records of its activities and sponsored the composition of an official history of the dynasty which it had succeeded, based on the primary records prepared by that dynasty. By so doing, each dynasty recognized implicitly that it in turn would be succeeded by a new ruling house whose historians would pass judgment upon it. Standard Chinese political theory fortified this dynastic cyclical concept. The idea of the Mandate of Heaven, without which no dynasty could rule, seems to have been originated in the eleventh century B.c. by the founders of the Chou dynasty, who attempted to add moral justification to military conquest by asserting that had cast down the wicked Shang rulers and exalted the virtuous Chou regime. This Mandate of theory eventually was taken up and elaborated by the Confucians. Mencius deduced from it the right of revolution: Heaven sees as the people see, hears as the people hear. There was no divine right of kings. Flood, famine, corruption and oppression were indications that Heaven's patience with the ruling house was wearing thin. Revolution and the setting up of a new and presumably righteous dynasty were justified. As Confucianism, in the Han period, became the state cult, and the practice of official composition of dynastic histories began to develop, this ethico-political cycle theory became the stock in trade of official historical interpretation and periodization. Historical writing had a distinct didactic slant. The wrongs and errors of past dynasties were lessons for the rulers of the present. History was conceived of as a series of dynasties, each at the outset representing the will of and hence of the people, each gradually losing its founding virtue and eventually being cast aside. The conventional systems of dating supplemented the Mandate of theory in supporting this dynastic-sequence scheme of periodization. Events were dated as taking place in a certain year of a certain nien hao (reign title) of a certain dynasty, such as the second day of the fifth month of