In Arabia no religion was tolerated save the faith of the Koran. But in all the countries beyond the limits of the peninsula, freedom of worship was allowed (save to _idolaters_, who were to be "rooted out"); unbelievers, however, must purchase this liberty by the payment of a moderate tribute. Yet notwithstanding this toleration, the Christian and Zoroastrian religions gradually died out almost everywhere throughout the domains of the Caliphs. [Footnote: The number of Guebers, or fire- worshippers, in Persia at the present time is estimated at from 50,000 to 100,000. About the same number may be counted in India, the descendants of the Guebers who fled from Persia at the time of the Arabian invasion. They are there called Parsees, from the land whence they came.] THE DEFECTS OF ISLAM.--Civilization certainly owes a large debt to the Saracens. They preserved and transmitted much that was valuable in the science of the Greeks and the Persians (see p. 472). They improved trigonometry and algebra, and from India they borrowed the decimal system of notation and introduced it into the West. Many of the doctrines of Islam, however, are most unfavorable to human liberty, progress, and improvement. It teaches fatalism, and thus discourages effort and enterprise. It allows polygamy and pelts no restraint upon divorce, and thus destroys the sanctity of the family life. It permits slavery and fosters despotism. It inspires a blind and bigoted hatred of race and creed, and thus puts far out of sight the salutary truth of the brotherhood of man. Because of these and other scarcely less prominent defects in its teachings, Islam has proved a blight and curse to almost every race embracing its sterile doctrines. Mohammedism is vastly superior, however, either to fetichism or idolatry, and consequently, upon peoples very low in the scale of civilization, it has an elevating influence. Thus, upon the negro tribes of Central Africa, where it is to-day spreading rapidly, it is acknowledged to have a civilizing effect. CHAPTER XXXVII. CHARLEMAGNE AND THE RESTORATION OF THE EMPIRE IN THE WEST. GENERAL REMARKS.--In the foregoing chapter we traced the rise and decline of the power of the Saracens. We saw the Semitic East roused for a moment to a life of tremendous energy by the miracle of religious enthusiasm, and then beheld it sinking rapidly again into inaction and weakness, disappointing all its early promises. Manifestly the "Law" is not to go forth from Mecca. The Semitic race is not to lead the civilization of the world.