Islam, or the Mohammedan monotheism, is the youngest and purest form of monotheism. When the young Mohammed (born 570) learned to despise the polytheistic idolatry of his Arabian compatriots, and became acquainted with Nestorian Christianity, he adopted its chief doctrines in a general way; but he could not bring himself to see anything more than a prophet in Christ, like Moses. He found in the dogma of the Trinity what every emancipated thinker finds on impartial reflection--an absurd legend which is neither reconcilable with the first principles of reason nor of any value whatever for our religious advancement. He justly regarded the worship of the immaculate mother of God as a piece of pure idolatry, like the veneration of pictures and images. The longer he reflected on it, and the more he strove after a purified idea of deity, the clearer did the certitude of his great maxim appear: "God is the only God"--there are no other gods beside him. Yet Mohammed could not free himself from the anthropomorphism of the God-idea. His one only God was an idealized, almighty man, like the stern, vindictive God of Moses, and the gentle, loving God of Christ. Still, we must admit that the Mohammedan religion has preserved the character of pure monotheism throughout the course of its historical development and its inevitable division much more faithfully than the Mosaic and Christian religions. We see that to-day, even externally, in its forms of prayer and preaching, and in the architecture and adornment of its mosques. When I visited the East for the first time, in 1873, and admired the noble mosques of Cairo, Smyrna, Brussa, and Constantinople, I was inspired with a feeling of real devotion by the simple and tasteful decoration of the interior, and the lofty and beautiful architectural work of the exterior. How noble and inspiring do these mosques appear in comparison with the majority of Catholic churches, which are covered internally with gaudy pictures and gilt, and are outwardly disfigured by an immoderate crowd of human and animal figures! Not less elevated are the silent prayers and the simple devotional acts of the Koran when compared with the loud, unintelligible verbosity of the Catholic Mass and the blatant music of their theatrical processions.