Our last considerations have clearly demonstrated how the individuality of the family unit shows itself in the aboriginal mode of living. A single family is normally in contact with a few other families only; sometimes it roams alone over its own area. But even when there are several families living together, the camp rules keep them apart from each other in nearly every function of daily life. The children, who live in intimate contact with their parents in the same hut, must necessarily set them apart from all their (the children's) other relatives. We must assume, therefore, that the individuality of the relation of each child to its actual parents is deeply impressed by all the circumstances of daily life on the child's mind. This assumption is in accord with the information we can gather on this point. But before we begin to look it through, let us discuss the theoretical side of the kinship (or relationship) problem. CHAPTER VI DISCUSSION OF KINSHIP I THEORETICAL ANALYSIS OF THIS CONCEPT It is undoubtedly one of the most valuable discoveries arrived at by modern sociological science that each institution varies in accordance with the social environment in which it is found. A given institution or social form (like the family, the state, the nation, the church) appears under various forms in different societies, and among peoples with a very low culture only rudiments thereof may be expected. This point of view, applied to marriage and the family, has led some writers to the assumption of forms as much opposed to those usual in our societies, as promiscuity and group marriage is opposed to individual marriage and the family. Nevertheless, although the variability and multiplicity of forms of marriage and family were acknowledged, the concepts applied to them were still the old ones, directly borrowed from our own society and formed upon the facts found amongst ourselves. In particular the sociologically untrained ethnographers comprehended the phenomena of kinship only under our own social concepts, judged them according to our own moral standard, and described them with words the meaning of which ought to have been defined when applied to a new case; nevertheless these terms have been nearly always used by ethnographers in the same sense in which we use them amongst ourselves, _i. e._ as expressing ideas of community of blood through procreation.[513] That this is quite erroneous will be shown below. How far the idea of kinship changes from society to society, what are its essential invariable features, and what are the variable elements--these are the problems that must be set forth. [513] Compare, for instance, Morgan, _Systems_, pp. 108 _sqq._ For other examples see below, pp. 199 _sqq._ Sir Laurence Gomme writes: "One of our greatest difficulties, indeed, is the indiscriminate use of kinship terms by our descriptive authorities."--_Loc. cit._, p. 235.