There remains, of course, the question of time; that these developments will take "thousands" or "hundreds" of years. Yet the interdependence of modern nations is the growth of little more than fifty years. A century ago England could have been self-supporting, and little the worse for it. One must not overlook the Law of Acceleration. The age of man on the earth is placed variously at from thirty thousand to three hundred thousand years. He has in some respects developed more in the last two hundred years than in all the preceding ages. We see more change now in ten years than originally in ten thousand. Who shall foretell the developments of a generation?
The progress from cannibalism to Herbert Spencer--The disappearance of religious oppression by government--Disappearance of the duel--The Crusaders and the Holy Sepulchre--The wail of militarist writers at man's drift away from militancy.
All of us who have had occasion to discuss this subject are familiar with the catch-phrases with which the whole matter is so often dismissed. "You cannot change human nature," "What man always has been during thousands of years, he always will be," are the sort of dicta generally delivered as self-evident propositions that do not need discussion. Or if, in deference to the fact that very profound changes, in which human nature is involved, _have_ taken place in the habits of mankind, the statement of the proposition is somewhat less dogmatic, we are given to understand that any serious modification of the tendency to go to war can only be looked for in "thousands of years."
That the alleged unchangeability of human nature in this matter is not borne out; that man's pugnacity though not disappearing, is very visibly, under the forces of mechanical and social development, being transformed and diverted from ends that are wasteful and destructive to ends that are less wasteful, which render easier that co-operation between men in the struggle with their environment which is the condition of their survival and advance; that changes which, in the historical period, have been extraordinarily rapid are necessarily quickening--quickening in geometrical rather than in arithmetical ratio.