MONOGAMY
Societies which from generation to generation produce in due abundance individuals who relatively to the requirements are the best physically, morally, and intellectually, must become the predominant societies, and must tend through the quiet process of industrial competition to replace other societies. Consequently, marital relations which favour this result in the highest degree must spread; while the prevailing sentiments and ideas must become so moulded into harmony with them that other relations will be condemned as immoral. The monogamic form of the sexual relations is manifestly the ultimate form; and any changes to be anticipated must be in the direction of completion and extension of it.
II.—Political Organisation
A society is formed only when, besides juxtaposition there is co-operation. Co-operation is made possible by society and makes society possible. It pre-supposes associative men; and men remain associated only because of the benefits co-operation yields them. But there cannot be concerted actions without agencies by which actions are adjusted in their times, amounts, and kinds; and the actions cannot be of different kinds without the co-operators undertaking different duties. That is to say, the co-operators must become organised, either voluntarily or involuntarily.
AGGREGATION
The political evolution manifested by increase of mass is political aggregation. One of the laws of evolution at large is that integration results when like units are subject to the same force or the like forces; and from the first stages of political integration to the last this law is illustrated. Likeness in the units forming a social group being one conditioned to their integration, a further condition is their joint reaction against external action: co-operation in war is the chief cause of social integration. The temporary unions of savages for offence and defence show the initiatory steps. When many tribes unite against a common enemy, long continuance of their combined action makes them coherent under some common control. And so it is subsequently with still larger aggregates.
DIFFERENTIATION
The state of homogeneity in the social aggregate is an unstable one. The primary political differentiation originates from the primary family differentiation. Men and women very early respectively form the two political classes of rulers and ruled. The slave class acquires separateness only as fast as there arrives some restrictions on the powers of the owners; slaves begin to form a division of the body politic when their personal claims begin to be distinguished as limiting the claims of their masters. Where men have passed into the agricultural or settled state it becomes possible for one community to take possession bodily of another community, along with the territory it occupies. When this happens, there arise additional class divisions. The class differentiation of which militancy is the actual cause is furthered by the establishment of definite descent, especially male descent, and by the transmission of position and property to the eldest son of the eldest continually. Inequalities of position and wealth once initiated tend to increase and to establish physical differences; and beyond these there are produced by the respective habits of life mental differences, emotional and intellectual, strengthening the general contrast of nature. When there come conquests which produce compound societies and doubly compound ones there result superpositions of ranks: while the ranks of the conquering society become respectively higher than those which have existed before, the ranks of the conquered society become respectively lower. The political differentiations which militancy originates and which for a long time increase in definiteness, are at later stages and under other conditions interfered with, traversed, and partially or wholly destroyed. While the higher political evolution of large social aggregates tends to break down the divisions of rank which grew up in the small component social aggregates, by substituting other divisions, these original divisions are still more broken down by growing industrialism. Generating a wealth that is not connected with rank, this initiates a compelling power; and at the same time, by establishing the equal positions of citizens before the law in respect of trading transactions, it weakens those divisions which at the outset expressed inequality of position before the law.
POLITICAL FORMS AND FORCES
In its primitive form political power is the feeling of the community acting through an agency which it has either informally or formally established; and this public feeling, while it is to some extent the feeling spontaneously formed by those concerned, it is to a much larger extent the accumulated and organised sentiment of the past. Everywhere we are shown that the ruler's function as regulator is mainly that of enforcing the inherited rules of conduct which embody ancestral sentiments and ideas.