The German Empire went beyond other states in adopting the ideal of national power, attained through an all-embracing militant organization, as the dominating conception of life. When the Great War broke out this conception was so largely justified by military results that the more “individualistic” nations—at first Great Britain and later the United States—were forced to adopt it, at least in part and for the time being, in order to hold their own; and we saw, accordingly, a growth of centralized and partly compulsory organization that would have been impossible in peace. At the same time the weak side of the state-conflict idea was revealed by Germany’s moral isolation. We are still in the midst of these changes and cannot be sure of their outcome, but it is certain that war has illumined the whole situation and opened a fresh cycle of growth. The difference between tribal society and the modern system of life lies mainly in the large-scale organic character of our whole social process. Formerly we lived in many small societies the relations among which were comparatively external and mechanical; now we live in one great society the parts of which are vitally and consciously united. The instances of this are familiar—the world-wide traffic, travel, and interchange of thought; the universal fashions, the international markets, the co-operation in science and in humanitarian movements. This is that modern solidarity, so wonderfully increased within the memory of living men, which makes the understanding of our life a new problem. The process is still one of struggle—we have no reason to expect anything else—but the forms of struggle take on a scale commensurate with the new system of life, and are conditioned and limited by the closer interdependence that has come to exist. The competitions of trade are for world-markets; races are unloosed from their ancient seats and encounter one another in all parts of the earth; and if a war comes the solidarity of life tends to draw many nations into it, and to make it in all respects more calamitous than war could have been at an earlier period.