The test of higher organization usually given is that of increasing differentiation of parts with corresponding specialization of function. But the main course of progress is not linear, or in one continuous direction; apparent reversions to former types are only apparent; the new type stands higher than the old. In other words, history moves in cycles. It follows, from this, that mere differentiation is insufficient for definition. While the differentiation advances, its significance alters, or, let us say, the relative places of specialization and of unity alter. Along with differentiation goes a process of integration. Great revolutions simplify. The result of greater and greater heterogeneity is to produce a new principle, which combines the warring elements. The definition of progress by increased differentiation is lacking in two ways: It tells us nothing of the forces by which progress is produced, and it gives no connected view of the actual facts of historical development. A general statement of progress in its formal sense is found in the conception of a struggle of ideals. But as in this struggle the survival of the fittest does not necessarily mean the destruction of those who represented the defeated ideal, but the supplanting of their ideal by another, the movement is one of comprehension, and we should expect to find, and do find, the history of morality exhibit the gradual development of a universal moral order, good not for one group of men but for all. It would be a misapprehension to regard this change as merely quantitative, as if the virtues were the same whether they applied on a larger or a smaller scale. "The quantitative extension is parallel with, and in reality proceeds from, a change in the conception of the human person himself." In primitive communities, the individual is so limited that he can hardly be called an individual at all. First among the Greeks do we find the person the embodiment of the social order, but in a limited sense. "When this limitation breaks down, and the individual stands forth as independent and self-conscious, the author of the laws he obeys, we have at the same time the extension of the area of persons with whom he is in moral relation." "It matters little that the Western ideal of a society of humanity is realized to so slight an extent. The ideal exists and implies the inclusion of mankind." The principle of democracy, which we are engaged in working out, "continues, or perhaps supersedes, under much more complex conditions and over a wider range of institutions, the same principle as Christianity introduced." It is not merely an identical element in many individual states, but a comprehensive ideal. The power of naturalization, extradition laws, international action among the working classes, etc., imply this.