In dealing, not with groups of human beings in simple and primitive relations, but with highly complex, highly specialized, civilized, or semi-civilized societies, there is need of great caution in drawing analogies with what has occurred in the development of the animal world. Yet even in these cases it is curious to see how some of the phenomena in the growth and disappearance of these complex, artificial groups of human beings resemble what has happened in myriads of instances in the history of life on this planet.

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.

But there are plenty of other phenomena wholly or partially inexplicable. It is easy to see why Rome trended downward when great slave-tilled farms spread over what had once been a country-side of peasant proprietors, when greed and luxury and sensuality ate like acids into the fibre of the upper classes, while the mass of the citizens grew to depend not upon their own exertions, but upon the State, for their pleasures and their very livelihood. But this does not explain why the forward movement stopped at different times, so far as different matters were concerned; at one time as regards literature, at another time as regards architecture, at another time as regards city-building. There is nothing mysterious about Rome's dissolution at the time of the barbarian invasions; apart from the impoverishment and depopulation of the Empire, its fall would be quite sufficiently explained by the mere fact that the average citizen had lost the fighting edge—an essential even under a despotism, and therefore far more essential in free, self-governing communities, such as those of the English-speaking peoples of to-day. The mystery is rather that out of the chaos and corruption of Roman society during the last days of the oligarchic republic, there should have sprung an Empire able to hold things with reasonable steadiness for three or four centuries. But why, for instance, should the higher kinds of literary productiveness have ceased about the beginning of the second century, whereas the following centuries witnessed a great outbreak of energy in the shape of city-building in the provinces, not only in Western Europe, but in Africa? We cannot even guess why the springs of one kind of energy dried up, while there was yet no cessation of another kind.

Take another and smaller instance, that of Holland. For a period covering a little more than the seventeenth century, Holland, like some of the Italian city-states at an earlier period, stood on the dangerous heights of greatness, beside nations so vastly her superior in territory and population as to make it inevitable that sooner or later she must fall from the glorious and perilous eminence to which she had been raised by her own indomitable soul. Her fall came; it could not have been indefinitely postponed; but it came far quicker than it needed to come, because of shortcomings on her part to which both Great Britain and the United States would be wise to pay heed. Her government was singularly ineffective, the decentralization being such as often to permit the separatist, the particularist, spirit of the provinces to rob the central authority of all efficiency. This was bad enough. But the fatal weakness was that so common in rich, peace-loving societies, where men hate to think of war as possible, and try to justify their own reluctance to face it either by high-sounding moral platitudes, or else by a philosophy of short-sighted materialism. The Dutch were very wealthy. They grew to believe that they could hire others to do their fighting for them on land; and on sea, where they did their own fighting, and fought very well, they refused in time of peace to make ready fleets so efficient, as either to insure them against the peace being broken, or else to give them the victory when war came. To be opulent and unarmed is to secure ease in the present at the almost certain cost of disaster in the future.

It is therefore easy to see why Holland lost when she did her position among the powers; but it is far more difficult to explain why at the same time there should have come at least a partial loss of position in the world of art and letters. Some spark of divine fire burned itself out in the national soul. As the line of great statesmen, of great warriors, by land and sea, came to an end, so the line of the great Dutch painters ended. The loss of pre-eminence in the schools followed the loss of pre-eminence in camp and in council chamber.

In the little republic of Holland, as in the great empire of Rome, it was not death which came, but transformation. Both Holland and Italy teach us that races that fall may rise again. In Holland, as in the Scandinavian kingdoms of Norway and Sweden, there was in a sense no decadence at all. There was nothing analogous to what has befallen so many countries; no lowering of the general standard of well-being, no general loss of vitality, no depopulation. What happened was, first a flowering time, in which the country's men of action and men of thought gave it a commanding position among the nations of the day; then this period of command passed, and the State revolved in an eddy, aside from the sweep of the mighty current of world life; and yet the people themselves in their internal relations remained substantially unchanged, and in many fields of endeavor have now recovered themselves, and play again a leading part.

In Italy, where history is recorded for a far longer time, the course of affairs was different. When the Roman Empire that was really Roman went down in ruin, there followed an interval of centuries when the gloom was almost unrelieved. Every form of luxury and frivolity, of contemptuous repugnance for serious work, of enervating self-indulgence, every form of vice and weakness which we regard as most ominous in the civilization of to-day, had been at work throughout Italy for generations. The nation had lost all patriotism. It had ceased to bring forth fighters or workers, had ceased to bring forth men of mark of any kind; and the remnant of the Italian people cowered in helpless misery among the horse-hoofs of the barbarians, as the wild northern bands rode in to take the land for a prey and the cities for a spoil. It was one of the great cataclysms of history; but in the end it was seen that what came had been in part change and growth. It was not all mere destruction. Not only did Rome leave a vast heritage of language, culture, law, ideas, to all the modern world; but the people of Italy kept the old blood as the chief strain in their veins. In a few centuries came a wonderful new birth for Italy. Then for four or five hundred years there was a growth of many little city-states which, in their energy both in peace and war, in their fierce, fervent life, in the high quality of their men of arts and letters, and in their utter inability to combine so as to preserve order among themselves or to repel outside invasion, cannot unfairly be compared with classic Greece. Again Italy fell, and the land was ruled by Spaniard or Frenchman or Austrian; and again, in the nineteenth century, there came for the third time a wonderful new birth.

Contrast this persistence of the old type in its old home, and in certain lands which it had conquered, with its utter disappearance in certain other lands where it was intrusive, but where it at one time seemed as firmly established as in Italy—certainly as in Spain or Gaul. No more curious example of the growth and disappearance of a national type can be found than in the case of the Græco-Roman dominion in Western Asia and North Africa. All told it extended over nearly a thousand years, from the days of Alexander till after the time of Heraclius. Throughout these lands there yet remain the ruins of innumerable cities which tell how firmly rooted that dominion must once have been. The over-shadowing and far-reaching importance of what occurred is sufficiently shown by the familiar fact that the New Testament was written in Greek; while to the early Christians, North Africa seemed as much a Latin land as Sicily or the Valley of the Po. The intrusive peoples and their culture flourished in the lands for a period twice as long as that which has elapsed since, with the voyage of Columbus, modern history may fairly be said to have begun; and then they withered like dry grass before the flame of the Arab invasion, and their place knew them no more. They overshadowed the ground; they vanished; and the old types reappeared in their old homes, with beside them a new type, the Arab.

Now, as to all these changes we can at least be sure of the main facts. We know that the Hollander remains in Holland, though the greatness of Holland has passed; we know that the Latin blood remains in Italy, whether to a greater or less extent; and that the Latin culture has died out in the African realm it once won, while it has lasted in Spain and France, and thence has extended itself to continents beyond the ocean. We may not know the causes of the facts, save partially; but the facts themselves we do know. But there are other cases in which we are at present ignorant even of the facts; we do not know what the changes really were, still less the hidden causes and meaning of these changes. Much remains to be found out before we can speak with any certainty as to whether some changes mean the actual dying out or the mere transformation of types. It is, for instance, astonishing how little permanent change in the physical make-up of the people seems to have been worked in Europe by the migrations of the races in historic times. A tall, fair-haired, long-skulled race penetrates to some southern country and establishes a commonwealth. The generations pass. There is no violent revolution, no break in continuity of history, nothing in the written records to indicate an epoch-making change at any given moment; and yet after a time we find that the old type has reappeared and that the people of the locality do not substantially differ in physical form from the people of other localities that did not suffer such an invasion. Does this mean that gradually the children of the invaders have dwindled and died out; or, as the blood is mixed with the ancient blood, has there been a change, part reversion and part assimilation, to the ancient type in its old surroundings? Do tint of skin, eyes and hair, shape of skull, and stature, change in the new environment, so as to be like those of the older people who dwelt in this environment? Do the intrusive races, without change of blood, tend under the pressure of their new surroundings to change in type so as to resemble the ancient peoples of the land? Or, as the strains mingled, has the new strain dwindled and vanished, from causes as yet obscure? Has the blood of the Lombard practically disappeared from Italy, and of the Visigoth from Spain, or does it still flow in large populations where the old physical type has once more become dominant? Here in England, the long-skulled men of the long barrows, the short-skulled men of the round barrows, have they blended, or has one or the other type actually died out; or are they merged in some older race which they seemingly supplanted, or have they adopted the tongue and civilization of some later race which seemingly destroyed them? We cannot say. We do not know which of the widely different stocks now speaking Aryan tongues represents in physical characteristics the ancient Aryan type, nor where the type originated, nor how or why it imposed its language on other types, nor how much or how little mixture of blood accompanied the change of tongue.

The phenomena of national growth and decay, both of those which can and those which cannot be explained, have been peculiarly in evidence during the four centuries that have gone by since the discovery of America and the rounding of the Cape of Good Hope. These have been the four centuries of by far the most intense and constantly accelerating rapidity of movement and development that the world has yet seen. The movement has covered all the fields of human activity. It has witnessed an altogether unexampled spread of civilized mankind over the world, as well as an altogether unexampled advance in man's dominion over nature; and this together with a literary and artistic activity to be matched in but one previous epoch. This period of extension and development has been that of one race, the so-called white race, or, to speak more accurately, the group of peoples living in Europe, who undoubtedly have a certain kinship of blood, who profess the Christian religion, and trace back their culture to Greece and Rome.