been selected and its defences constrncted by the foresight and energy of the great Constantine. At last it fell (1453) before the conquering Turk, as falls every work of man, however wisely built or however stupendous, vniless its bulwarks are the continued energy, virtue, and intelligence of the people who enjoy its protection.
We have seen how, five hundred years before the Christian era, the great kings of Persia drew their physicians from the Greek schools of medicine. The Alexandrian dynasties had long since passed away, and it is significant to note to how low a level Greek medicine had sunk among the bastard descendants of that noble race to find another line of Persian kings sending Arabian physicians to Constantinople to minister to the many bodily ills of some of the Greek emperors; but it was first through Greek physicians, through the exiles whom the fanaticism of the theologians of Constantinople had driven into Persia, that the Arabs received the first inoculation of the virus of learning. It was through the exiles driven by anarchy and the forebodings of impending ruin, as well as by its culmination that Italy first received the direct impetus from Greek sources which resulted in the Renaissance. From the Nestorians the Arabians not only absorbed profane knowledge, but from them the youth Mohammed on his caravan trips drew the inspiration of his religion. Not only the Nestorians, but still more perhaps the Jews, who taught their religion to both Christ and Mohammed, aided in this transfer of learning to the Arabians.
The Arabian Conquest. — Four years after the death of Justinian, Mahomet, the only son of Abdalla, was born at Mecca in 569 A.D. Heraclius, after his great victories over the Persians, was weighted down by age and disease, and his empire was exhausted by years of destructive warfare. Therefore the feeble races under the sway both of the Persian and of the Holy Roman Empire of the East were easy conquests for the sturdy Arab. The forces of nature are eternal, their laws immutable, and the results of their activity when surveyed over long periods of time and sufficient expanse of space, appear analogous even to the finite understanding of man. The expansion of the Mohametan crescent rapidly grew until in a period of less than a century from the death of Mahomet in 632 a.d. one horn rested in the fertile valleys of Spain (710 A.D.) and the other menaced the walls of Constantinople itself. The fanaticism which is easily engendered in the populations of Asia has made it the cradle of religions. The poverty and hardships of the human beings who struggled among the burning sands of Arabia weeded out the weaklings of the race and trained the endurance of the survivors to resist the effects of thirst, hunger, and fatigue, and when fired by the visions of Mahomet with the prospects of glory and power and with the hope of the indulgence
