The great revolution which in the seventh century of the Christian era agitated all Arabia and gave a new trend to vast currents of world history was essentially a moral revolution. It was the moral degradation of the Arab tribes, still clinging to an outgrown, idolatrous worship incapable longer of giving moral guidance to its followers, that stirred the soul and inspired the message of Mohammed. The Prophet’s real appeal was to the conscience of the Arab race. The chief aim and purpose of his preaching was to effect a moral reform. He gave the Arabs, it is true, a new religion, but the religion was to give impulse and sanction to the new morality. The transformation which the new faith wrought in the moral consciousness of the Arabian nation was probably not less profound than that effected by Christianity in the moral consciousness of the European peoples. It is this which makes the rise of Islam a matter as important in the moral as in the religious history of mankind. [Sidenote: The doctrine of the unity of God] Islam may, with strict historical accuracy, be said to be essentially a republication of Judaism. Its morality, like the old Hebrew morality, is largely derived from its conception of deity. It teaches that God is one, and that he is all-powerful, compassionate, forgiving, and righteous. Allah is great and merciful and just, is the burden of the Prophet’s message respecting deity. This ethical monotheism has been a governing force in the moral life of the Mohammedan world, just as a like ethical monotheism has been a molding influence in the moral life of the Jews and of all those nations that have received their religion from them. [Sidenote: The dogma of salvation by belief] Another religious doctrine which has contributed largely to shape the morality of Islam is that of salvation by belief. Only the true believer can be saved. The tendency, indeed the logical and inevitable consequence of this doctrine, has been to make Islam one of the most intolerant of the great religions. It has tended to restrict the moral sympathies of Moslems to coreligionists and to make propagandism by violence seem a virtue. [Sidenote: An unchangeable moral law] Islam claims to be a divine revelation to man. This doctrine of the supernatural origin of the religion makes the moral code, which is bound up with it, a rigid, unchangeable law, for it is only a human code that can be changed without irreverence and sacrilege. The blighting effects upon Mohammedan morality of this dogma of a moral law supernaturally given for all time will be noted a little later, when we come to speak of the actual moral life in Mohammedan lands. II. THE MORAL CODE [Sidenote: General nature of the code]