selves to Motion in a universe of Motions, with an acceleration, in their own case, of vertiginous violence. With the correctness of their science, history had no right to meddle, since their science now lay in a plane where scarcely one or two hundred minds in the world could follow its mathematical processes; but bombs educate vigorously, and even wireless telegraphy or air-ships might require the reconstruction of society. If any analogy whatever existed between the human mind, on one side, and the laws of motion, on the other, the mind had already entered a field of attraction so violent that it must immediately pass beyond, into new equilibrium, like the Comet of Newton, or suffer dissipation altogether, like meteoroids in the earth's atmosphere. If it behaved like an explosive, it must rapidly recover equilibrium; if it behaved like a vegetable, it must reach its limits of growth; and even if it acted like the earlier creations of energy,—the Saurians and Sharks,—it must have nearly reached the limits of its expansion. If science were to go on doubling or quadrupling its complexities every ten years, even mathematics would soon succumb. An average mind had succumbed already in 1850; it could no longer understand the problem in 1900.
Fortunately, a student of history had no responsibility for the problem; he took it as science gave it, and waited only to be taught. With science or with society, he had no quarrel and claimed no share of authority. He had never been able to acquire knowledge, still less to impart it; and if he had, at times, felt serious differences with the American of the nineteenth century, he felt none with the American of the twentieth. For this new creation, born since 1900, a historian asked no longer to be teacher or even friend; he asked only to be a pupil, and promised to be docile, for once, even though trodden under foot; for he could see that the new American,—the child of incalculable coal-power, chemical power, electric power, and radiating energy, as well as of new forces yet undetermined,—must be a sort of God compared with any former creation of nature. At the rate of progress since 1800, every American who lived to the year 2000 would know how to control unlimited power. He would think in complexities unimaginable to an earlier mind. He would deal with problems altogether beyond the range of earlier society. To him the nineteenth century would stand on the same plane with the fourth,—equally childlike,—and he would only
