But what ARE nations? What are these groups which are so familiar to us, and yet, if we stop to think, so strange; which are as old as history; which Herodotus found in almost as great numbers and with quite as marked distinctions as we see them now? What breaks the human race up into fragments so unlike one another, and yet each in its interior so monotonous? The question is most puzzling, though the fact is so familiar, and I would not venture to say that I can answer it completely, though I can advance some considerations which, as it seems to me, go a certain way towards answering it. Perhaps these same considerations throw some light, too, on the further and still more interesting question why some few nations progress, and why the greater part do not. Of course at first all such distinctions of nation and nation were explained by original diversity of race. They ARE dissimilar, it was said, because they were created dissimilar. But in most cases this easy supposition will not do its work. You cannot (consistently with plain facts) imagine enough original races to make it tenable. Some half-dozen or more great families of men may or may not have been descended from separate first stocks, but sub-varieties have certainly not so descended. You may argue, rightly or wrongly, that all Aryan nations are of a single or peculiar origin, just as it was long believed that all Greek-speaking nations were of one such stock. But you will not be listened to if you say that there were one Adam and Eve for Sparta, and another Adam and Eve for Athens. All Greeks are evidently of one origin, but within the limits of the Greek family, as of all other families, there is some contrast-making force which causes city to be unlike city, and tribe unlike tribe.