Christianity had a great moral superiority over Roman paganism, in its humane doctrine of universal brotherhood, its unselfishness, its holiness; and thereby it attracted to itself (among other and baser materials) all the purest natures and most enthusiastic temperaments.  Its first conquests were noble and admirable.  But there is nothing superhuman or unusual in this.  Mohammedism in the same way conquers those Pagan creeds which are morally inferior to it.  The Seljuk and the Ottoman Turks were Pagans, but adopted the religion of Tartars and Persians whom they subjugated, because it was superior and was blended with a superior civilization; exactly as the German conquerors of the Western Empire of Rome adopted some form of Christianity.

But if it is true that the sword of Mohammed was the influence which subjected Arabia, Egypt, Syria and Persia to the religion of Islam, it is no less true that the Roman empire was finally conquered to Christianity by the sword.  Before Constantine, Christians were but a small fraction of the empire.  In the preceding century they had gone on deteriorating in good sense and most probably therefore in moral worth, and had made no such rapid progress in numbers as to imply that by the mere process of conversion they would ever Christianize the empire.  That the conversion of Constantine, such as it was, (for he was baptized only just before death,) was dictated by mere worldly considerations, few modern Christians will deny.  Yet a great fact is here implied; viz., that Christianity was adopted as a state-religion, because of the great political power accruing from the organization of the churches and the devotion of Christians to their ecclesiastical citizenship.  Roman statesmen well knew that a hundred thousand Roman citizens devoted to the interests of Rome, could keep in subjection a population of ten millions who were destitute of any intense patriotism and had no central objects of attachment.  The Christian church had shown its immense resisting power and its tenacious union, in the persecution by Galerius; and Constantine was discerning enough to see the vast political importance of winning over such a body; which, though but a small fraction of the whole empire, was the only party which could give coherence to that empire, the only one which had enthusiastic adherents in every province, the only one on whose resolute devotion it was possible for a partizan to rely securely.  The bravery and faithful attachment of Christian regiments was a lesson not lost upon Constantine; and we may say, in some sense, that the Christian soldiers in his armies conquered the empire (that is, the imperial appointments) for Christianity.  But Paganism subsisted, even in spite of imperial allurements, until at length the sword of Theodosius violently suppressed heathen worship.  So also, it was the spear of Charlemagne which drove the Saxons to baptism, and decided the extirpation