700-1449

The year 700 was a turning point in history because it marked the beginning of the medieval era. In the west, small European kingdoms began to unite into larger ones. In the Middle East Islam asserted itself politically and soon became a dominant cultural force. In both Christendom and the Dar-al-Islam the knowledge of ancient civilizations provided a foundation for the long period of growth toward modern western civilization, yet the continuity of learning in these two spheres was quite different.

In marked contrast, Far Eastern civilization was based on centuries of uninterrupted learning. Chinese physical science had begun as early as 2000 B.C., with observational astronomy and a 12-month calendar. Chinese optics was as ancient as that of the Greeks. Alchemy, too, had its roots in Asia in the second century A.D.

Things were also different in the West, where barbarian invasions...