It is, at the same time, conceded that the view thus suggested cannot be accepted without qualification. If we carry our thoughts as far forward as palaeolithic implements carry them back, we are introduced, not to an absolute optimism, but to a relative optimism. The cosmic process brings about retrogression, as well as progression, where the conditions favor it. Only amid an infinity of modifications, adjusted to an infinity of changes of circumstances, do there now and then occur some which constitute an advance: other changes, meanwhile, caused in other organisms, usually not constituting forward steps in organization, and often constituting steps backward. Evolution does not imply a latent tendency to improve everywhere in operation. There is no uniform ascent from lower to higher, but only an occasional production of a form, which, in virtue of greater fitness for more complex conditions, becomes capable of a longer life of a more varied kind. And, while such higher type begins to dominate over lower types, and to spread at their expense, the lower types survive in habitats or modes of life that are not usurped, or are thrust into inferior habitats or modes of life in which they retrogress. Mr. Spencer's examination of "The Principles of Sociology" has led him to the belief that what holds with organic types must hold also with types of society. Social evolution throughout the future, like social evolution throughout the past, must, while producing, step after step, higher societies, leave outstanding many lower. Varieties of men adapted here to inclement regions, there to regions that are barren, and elsewhere to regions unfitted, by ruggedness of surface or insalubrity, for supporting large populations, will, in all probability, continue to form small communities of simple structures. Moreover, during future competitions among the higher races, there will probably be left, in the less desirable regions, minor nations formed of men inferior to the highest; at the same time that the highest overspread all the great areas which are desirable in climate and fertility. But while the entire assemblage of societies thus fulfils the law of evolution by increase of heterogeneity,--while within each of them contrasts of structure, caused by differences of environments and entailed occupations, cause unlikenesses implying further heterogeneity, we may infer that the primary process of evolution--integration--which, up to the present time, has been displayed in the formation of larger and larger nations, will eventually reach a still higher stage, and bring yet greater benefits. As when small tribes were welded into great tribes, the head chief stopped inter-tribal warfare; as, when small feudal governments became subject to a king, feudal wars were prevented by him,--so, in time to come, a federation of the highest nations, exercising supreme authority (already foreshadowed by occasional agreements among "the