问答题 The scientific interest of American history centered in national character, and in the workings of a society destined to become best, in which individuals were important chiefly as types. Although this kind of interest was different from that of European history, it was at least as important to the world. Should history ever become a true science, it must expect to establish its laws, not from the complicated story of rival European nationalities, but from the economical evolution of a great democracy. North America was the most favorable field on the globe for the spread of a society so large, uniform, and isolated as to answer the purposes of science. There a single homogeneous society could easily attain proportions of three or four hundred million persons, under conditions of undisturbed growth. In Europe or Asia, undisturbed social evolution had been unknown. Without disturbance, evolution seems to cease. Wherever disturbance occurred, permanence was impossible. Every people in turn adapted itself to the law of necessity.无