Coming now to the analysis of the forms of society, the beginner must first of all face the problem: "What makes a people one?" Neither blood, nor territory, nor language, but only the fact of being more or less compactly organized in a political society, will be found to yield the unifying principle required. Once the primary constitution of the body politic has been made out, a limit is set up, inside of which a number of fairly definite forms of grouping offer themselves for examination; whilst outside of it various social relationships of a vaguer kind have also to be considered. Thus, amongst institutions of the internal kind, the family by itself presents a wide field of research; though in certain cases it is liable to be overshadowed by some other sort of organization, such as, notably, the clan. Under the same rubric fall the many forms of more or less voluntary association, economic, religious, and so forth. On the other hand, outside the circle of the body politic there are, at all known stages of society, mutual understandings that regulate war, trade, travel, the celebration of common rites, the interchange of ideas. Here, then, is an abundance of types of human association, to be first scrutinized separately, and afterwards considered in relation to each other. Closely connected with the previous subject is the history of law. Every type of association, in a way, has its law, whereby its members are constrained to fulfil a certain set of obligations. Thus our student will pass on straight from the forms of society to the most essential of their functions. The fact that, amongst the less civilized peoples, the law is uncodified and merely customary, whilst the machinery for enforcing it is, though generally effective enough, yet often highly indefinite and occasional, makes the tracing of the growth of legal institutions from their rudiments no less vitally important, though it makes it none the easier. The history of authority is a strictly kindred topic. Legislating and judging on the one hand, and governing on the other, are different aspects of the same general function. In accordance, then, with the order already indicated, law and government as administered by the political society in the person of its representatives, chiefs, elders, war-lords, priest-kings, and so forth, must first be examined; then the jurisdiction and discipline of subordinate bodies, such as the family and the clan, or again the religious societies, trade guilds, and the rest; then, lastly, the international conventions, with the available means of ensuring their observance.