The paper discusses the historical roots of the political cultures of Japan and China by examining the principal characteristics of their traditional Imperial systems. Comparison of the logic of legitimacy in each case, namely divine lineage in Japan in contrast to the awesome but demanding Mandate of Heaven in China, highlights the philosophical difference between reigning and ruling, and the consequences of this for modem politics in each country. A sacral aura still surrounds the Japanese system tending to insulate authority (...) from the kind of pressures that could lead, in China, to the loss of the Mandate, most recently based on socialist ideals. The power of continuity in both systems, surviving into the present in different forms, remains a serious possible impediment to the further political development of modem Asia. (shrink)