"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 shadows 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."