Our world—one says today—is rapidly shrinking, and there is evidence to support this claim. In its most obvious meaning, globalization denotes the progressive shrinkage of the world into a relatively circumscribed cosmopolis, a "global village" or a 'spaceship earth." These expressions are more than metaphors. With accelerating speed, space explorations, jet travel, and the internet demonstrate the spatial contraction of the earth, the steady attenuation, perhaps even elimination of spatial distances. "Yet, despite their plausibility, images of this kind miss an important point. What is usually neglected in globalization accounts is the fact that human societies and cultures live not only in space but also in time, and there is no evidence of a collapse of temporal distances. One way to put the matter is to say that, in different cultures, history has a different significance and obeys different narrative structures. In the context of Western civilization, it is customary among historians to distinguish between the periods of antiquity, the Middle Ages, and modernity; however, it would be futile to try to generalize or "globalize" this periodization. Thus, in the long unfolding of Chinese civilization one would look in vain for a period corresponding to the European Middle Ages. More pointedly still: the time period of the European Middle Ages coincides in Islamic civilization with Islam's gloriously vibrant "classical" age; and the same period witnessed in China the impressive flourishing of the Sung dynasty.¹