It might be plausibly contended that the religious movement of the prophet Mohammed could be accounted for in accordance with the doctrine of the correlation of forces. It is to be remembered that the personality of Mohammed is no more the equivalent of the vast movement which has existed and exists to-day under his name, than the acorn is the quantitative equivalent of the immense oak tree which has grown from it. The acorn, plus all the oxygen, carbon, hydrogen, nitrogen, and other forces of sky and earth which it caught and organized, is the equivalent of the oak tree. The soil and the sky contain oaks in solution. Through acorns these are precipitated into trees. The mental, political, and social atmosphere of Turkey contained the Mohammedan movement in solution before Mohammed was born. Through him it was precipitated into Koran, mosque, prayer, and worship. Mohammed relied for success upon the methods with which men ordinarily succeed. He appealed to men’s love of fame, of pleasure, of conquest, of power, of riches. He simply organized the latent aspirations, and hopes, and fears of his countrymen into a great kingdom, essentially secular and sensual. In accordance with the principle of the correlation of forces, it might be possible to account for the success of Buddha, Confucius, Cæsar, and Bonaparte. What we wish now, is to apply this doctrine, which the materialists claim is capable of measuring everything, from an atom to Milton’s “Paradise Lost,” to the life and work of Christ. Granting, as we must, that all physical force may be estimated by it, and even that the work and thought of men, in so far as they live under the natural law of selfishness or exclusiveness, may be estimated by it. What we desire to inquire is, if the life and work of Christ form no exception to its operation, as ordinarily regarded. Can we, in accordance with this principle, account for the life and influence of Christ on the assumption that he was only a man? Has no more force issued from the person of Christ than subsided when only a man named Jesus was crucified? We have seen how the forms of physical force in the shape of fuel, food, moving waters, and winds may be traced directly to the sun. Let us also consider some of the forms of spiritual force which are traceable directly to the life of Christ, and inquire if they may be accounted for as the force which comes from the sun may be, by the principle of the convertibility of force. IV.