But the pendulum sometimes swings very slowly, and oscillates within narrow limits; while at other times the changes are violent and rapid. The last century and a half, beginning with what Arnold Toynbee was the first to call the Industrial Revolution, has been a period of more rapid change than any other which history records. The French Revolution, which coincided with its first stages, helped to break the continuity between the old order and the new, and both by its direct influence and by the vigorous reactions which it generated cleft society into conflicting elements. Then followed a Great War, which shook the social structure to its base, and awakened into intense vitality the slumbering enthusiasm of nationality. At the same time, a variety of mechanical inventions gave man an entirely new control over the forces of nature and a new knowledge of the laws of nature, and this new knowledge, not content with practical applications, soon revolutionised all the natural sciences, and profoundly affected both religion and philosophy. The reign of Queen Victoria, which I have chosen to mark the limits of my survey to-day, covered the latter half of this _saeculum mirabile_, the most wonderful century in human history. There are of course no beginnings or ends in history. We may walk for a few miles by the side of a river, noting its shallows and its rapids, the gorges which confine it and the plains through which it meanders; but we know that we have seen neither the beginning nor the end of its course, that the whole river has an unbroken continuity, and that sections, whether of space or time, are purely arbitrary. We are always sowing our future; we are always reaping our past. The Industrial Revolution began in reality before the accession of George III, and the French monarchy was stricken with mortal disease before Louis XV bequeathed his kingdom to his luckless successor.