Lindberg develops the widely believed thesis that the Christian Roman Empire became increasingly hostile to pagan scholarship, forcing a "brain drain" to Asia of pagan thinkers and teachers. He gives the following example: "We see the results in the invitation issued by the Persian king Khusraw I about 531, to the philosophers from the Academy in Athens (expelled by a decree of the Byzantine Emperor Justinian), to settle in Persia." (164)
Thus the academy that had begun as a series of informal discussions between Socrates and his followers in the 5th Century B.C.E. in Athens closed its doors a thousand years later.
Sarton agrees with Lindberg and points out the fugitive nature of Greek science: "The move from Athens to Alexandria was due to political causes, that from Egypt and Greece to Asia very largely to religious ones." (Sarton 109) He summarizes, "Greek scholars were driven out of the Greek world and helped to develop Arabic science. Later, the Arabic writing was translated into Latin, into Hebrew, and into our own vernaculars. The treasure of Greek science, most of it at least, came to us through an immense detour." (Sarton 111)
The diffusion of Greek learning toward the East took nearly a thousand years, from the time of Alexander the Great, who marched Greek armies as far east as India in the 4th Century B.C.E., to the time of the founding of Islam in the 7th Century B.C.E. (Lindberg 165)
Legend credits the Arabs with the destruction of the Library at Alexandria when they sacked the city in 646, but Sarton (12) claims that it declined gradually over the course of centuries and that Christianity had much to do with its decline: "In 391, Theophilos (Bishop of Alexandria, 385-412), wishing to put an end to paganism, destroyed the Serapeion." (The Serapeion was the building that then held the scrolls that had survived after the main library disappeared.)