But this was not all. These conquests brought Islam in contact with Christendom along all its extended frontier from the Straits of Gibraltar to the Bosporus, and thus created the conditions which led to the Holy Wars between Moslem and Christian, which filled the eleventh and twelfth centuries. Such were the momentous and far-reaching consequences of the giving by the Arabian Prophet of a religious sanction to war, and the reënforcing of the war spirit among a martial race by making warfare a duty and death in battle a sure passport to the bliss of paradise. [Sidenote: Mitigation of Oriental barbarities in war] While adopting and sanctifying the war system, Islam did something in the way of mitigating its savagery. Up to this time the war code of the Asian peoples had lost little or none of its primitive barbarity. The indiscriminate slaughter of the vanquished, without regard to age or sex, had been a common practice. But when the second Arabian caliph, Omar, sent out his warriors to effect the conquest of the world for the true religion, he strictly enjoined them to spare the women and children and the old men. This injunction became a part of the Mohammedan war code, and, though not always observed, it did much to make the earlier wars waged for the spread of Islam, compared with most of the recorded wars among the Oriental races, merciful and humane. [Sidenote: Intolerance as a corollary of religious principles] Intimately related to the subject of the Mohammedan ethics of war is the subject of toleration. As we have seen, the natural tendency of the teaching that right religious belief is necessary to salvation, and that fighting for the spread of the true religion is a paramount duty, is to foster intolerance, indeed, is to make intolerance a virtue. These doctrines of Islam have in the main restricted to the faithful the outgoings of the moral sympathies. To the moral consciousness of the Moslem masses tolerance has not presented itself as a virtue at all, but rather as a reprehensible disposition of mind, since it argues lack of zeal for the true faith. There is to-day more religious intolerance in Moslem lands than in any other regions of the earth. In this respect the Mohammedan world is about at the standpoint held by Christendom in the Middle Ages. But fortunately it is the same with a bad principle as with a good one--it never produces its full logical consequences. There is that in the constitution of things and in human nature which prevents this. Hence there has been in Mohammedan lands a larger measure of toleration than, in view of the teachings of Islam, we should have looked for. But the toleration enjoyed by non-Moslems under Mohammedan rule has been at best precarious. With lamentable frequency, in lands where large sections of the population are ignorant and debased, outbursts of fanaticism have resulted in terrible massacres of “unbelievers.”