Why do great artificial empires, whose citizens are knit by a bond of speech and culture much more than by a bond of blood, show periods of extraordinary growth, and again of sudden or lingering decay? In some cases we can answer readily enough; in other cases we cannot as yet even guess what the proper answer should be. If in any such case the centrifugal forces overcome the centripetal, the nation will of course fly to pieces, and the reason for its failure to become a dominant force is patent to every one. The minute that the spirit which finds its healthy development in local self-government, and is the antidote to the dangers of an extreme centralization, develops into mere particularism, into inability to combine effectively for achievement of a common end, then it is hopeless to expect great results. Poland and certain Republics of the western hemisphere are the standard examples of failure of this kind; and the United States would have ranked with them, and her name would have become a byword of derision, if the forces of union had not triumphed in the Civil War. So, the growth of soft luxury after it has reached a certain point becomes a national danger patent to all. Again, it needs but little of the vision of a seer to foretell what must happen in any community if the average woman ceases to become the mother of a family of healthy children, if the average man loses the will and the power to work up to old age and to fight whenever the need arises. If the homely, commonplace virtues die out, if strength of character vanishes in graceful self-indulgence, if the virile qualities atrophy, then the nation has lost what no material prosperity can offset.