Æsculapius were closed with the rest, and medical like other science virtually died out of Christian hands, to be recovered from old Greek lore by the Saracens. Gregory the Great exhibits the superstition of an ignorant Asiatic. What the world needed above all things was new study and real knowledge in place of rhetoric: the fatality of the Christian system was that it set up the conviction that all vital knowledge was contained in itself. Yet all the while the religious habit of mind, which saw in pious fraud a service to deity, had almost destroyed the rational conception of truth, so that a thousand years were to elapse before human testimony could return to the standards of Thucydides, or human judgment rise above a gross credulity. Had it been only in the West, overrun by barbarism, that the lights of knowledge and art went out, the barbarian invasion might be put as the cause; but the history of Christian Byzantium is the history of an intellectual arrest of a thousand years on the very soil of civilization. § 4. The Social Failure Of the eastern Christian empire as it is left curtailed of more than half its area by the Moslem conquest, the one thing that cannot be predicated is progress or transformation. Here again it would be an error to regard Christianity as the cause of stagnation: the whole political science of antiquity had been markedly conservative; but it must be noted that historic Christianity absolutely endorsed the ideal of fixity. Only conditions of stimulating culture-contact could have preserved a vigorous mental life under its sway; and the condition of Byzantium was unhappily one of almost complete racial and religious isolation. The Byzantium of Justinian and Heraclius is almost the ideal of ossification; its very disorders are normal, the habitual outbreaks of a vicious organism. There is nothing in pagan history to compare with the chronic pandemonium set up in Christian Constantinople by the circus factions of blues and greens, whose mutual massacres in generation after generation outdid the slaughters of many civil wars. As painted by its own Christian censors, the Byzantine town population of all orders was at least as worthless as that of pagan Rome in its worst imperial days; it realized the ignorance and unprogressiveness of imperial China without the Chinese compensations of normal good nature, courtesy, domestic unity, and patient toil.