Is it not most truthful, and hence wisest, to recognize at the basis of these facts deep-seated elements of human nature? And what is more reasonable, from the standpoint of evolutionary biology, than to find these elements rooted in the age-long struggles of our omnivorous ancestors combining as best they could to win a short and brutish existence from a raw and none too friendly nature? Karl Pearson,1 from a comparative study of the femora of man and other primates, concludes that the ancestor of man was not like the shrinking tree shrew that runs to the tree tops on the approach of danger but"heavy in build and violent in character,""agile in motion, slender in his proportions, gracile in his bones, and dexterous in his flight from possible foes," "a violent fighter and a ravenous feeder." "We owe more than half our trouble to-day to this ancestry. Is the brutality and violence of man to-day a fall from 1 Pearson, Karl,"Side Lights on the Evolution of Man," Eugenics Laboratory Lecture Series, No. 13, p. 6, 1920.

a higher estate, or an atavism, a relic of a violent past?"Such a view, in so far as true, should not be looked upon as degrading to man. It does not alter his true nature, but is rather an effort to see him as he is. Human nature is no doubt deeply affected in its individual development by its social environment; moreover, civilization appears to grow less and less favorable to war and violence. But in all our longing for a pacific world, we must not overlook the advantages as well as the disadvantages that flow from man's courageous fighting qualities. In their absence it is inconceivable that he would have risen to the mastery of nature, conquered sea, desert, and mountain, or even performed brilliant feats of daring and endurance unparalleled elsewhere in the animal kingdom. Moreover, if through some mutational change or the slow effects of natural selection, he should everywhere become meek and docile, the course of social evolution and the character of social organization would be profoundly altered. They would be different; but whether they would be more satisfactory is a question.

Returning, then, for a moment to the gregarious tendency, we may note that the predominance of the group struggle for existence over all else depended upon and reinforced powerful sentiments of group solidarity. There must have been a time when groups were so small and territory so vast that conflicts between them were relatively infrequent. Such a condition still exists along the arctic fringe of human habitation. Elsewhere the competition for the best hunting grounds led very early to traditions of war, diplomacy, government, and peace. Man met in himself his most redoubtable enemy so that conflicts between groups became the supreme tests of racial quality, social organization, and cultural equipment. Man's native equipment made the cultivation of the art of war easy and inevitable. Accustomed to hunting in packs, the relation of leaders to followers, of authority to obedience, was a part of his original equipment; his courage, aggressiveness, vanity, and thrill in combat were ready to hand for military exploits; and his intelligence enabled him to utilize with unexampled skill those stratagems used by the wolf or dog pack in running their prey to earth, such as attacking en masse, or by surprise and stealth, surrounding, intercepting, ambushing, and similar movements.

With warfare a developed and immemorial habit, social organization and cultural evolution took forms adjusted thereto. Authority or government within the tribe or nation, the gradations of rank and occupation, the status of male and female, standards of honor, honorableness, and truth, and even religious institutions and practices are very largely adjusted to the exigencies of warfare. Tribal loyalty became the basic virtue. The distinction between what the late Professor Sumner aptly called the "in-group," or ourselves, and the "out-group,"or others, became sharp and incisive. Internal unity has always been enforced by the most powerful mandates of government, morality, and religion, in order that group strength might not be dissipated. The closer and stronger the enemy, the sterner has this internal discipline been. In consequence of this "struggle of races," as it was called by the eminent Austrian sociologist, Ludwig Gumplowicz, there arose that ethical dualism which has been the bane of all philosophical and universalized ethical systems. In relation to one's own gang, whether tribe, political party, or business group, one must be loyal, honest, truthful and steadfast, charitable and helpful. In relation to the "out-group" one becomes meritorious in proportion as he is deceitful, treacherous, lying, vacillating, cruel, and destructive. Moreover, whatever in the form of habit, custom, agency, or institution exemplifies one's own group becomes, in one's own esteem, vastly superior to the crude, ludicrous, or debased ways and possessions of the "out-group."One's own government, morals, and gods become sacred and inviolate, while those of the"out-group" are wicked and contemptible. Civilized man, to a very limited extent, outgrows these age-old attitudes, though warfare revives them even in those academic circles where scientific candor and objectivity are cultivated as the highest virtues. Moreover, they are sometimes explained as mere expressions of human vanity; whatever in any way typifies one's own group is to some extent identified with oneself. Consequently, one's own egoistic satisfaction requires that all such things be highly esteemed. This explanation is doubtless true so far as it goes.

At the same time, we may see in this spirit of clannish-ness both a consequence of, and an aid in, the group struggle for existence. "The strength of the wolf is the pack; and the strength of the pack is the wolf." What heightens individual courage and confidence increases the group chances of success. Confidence in the strength and superiority of one's race, and tradition and faith in the omnipotence of one's gods, are assertions of the group will to live and to conquer. In their absence, courage weakens and degeneration presages defeat and elimination. The study of the decay of tribal societies, both in this country and in the South Seas, reveals the profoundly significant fact that the crushing of tribal confidence by white supremacy destroys in the individual even the will to live and to reproduce.1