Bearing now in mind that what will be said hereafter applies in the first place to Australia, it may be said that in the physiological and social basis of kinship adopted above, the minimum of conditions necessary for the application of the idea of individual kinship was enumerated. But this minimum is not sufficient to determine this idea completely in any given society. By studying only the social facts which determine the individuality of family life within the society, we should not exhaust all the features and essential aspects of parental kinship in any society. The existence of the individual family merely indicates unambiguously that individual parental kinship exists in the given society. For this social unit having a deep analogy with our own individual family, the relation between the members of both these social units must also have some deep resemblance. But to exaggerate this resemblance would be as erroneous as to deny it. Besides the features common both to our parental kinship and to that of the Australian, there are also those which differentiate these two relationships. They must be sought for in the differences in the social conditions, which may even modify the physiological basis of kinship, as for instance when physical fatherhood is in one society established beyond doubt by exclusive sexual appropriation, while in the other there can be no question of it, owing to sexual communism. The variations in the general social conditions obviously also affect the purely sociological side of kinship. To point this out clearly, it is enough to mention that each relation is subject to the normative influences of the society in the midst of which it exists, and these norms and their sanction vary with the general social structure.
The variable elements in parental kinship must be also looked for in the different elements of the collective mind, connected with the parental relationship; in other words, in the different collective ideas and feelings which have parental kinship for their centre. Moreover, as mentioned above, there are reasons why the knowledge of the collective idea of kinship is sociologically important. It may be emphasized here that we should cripple and curtail our knowledge if we arbitrarily abstained from inquiring what influence the collective knowledge as to procreation, consanguinity, affinity, etc., may have upon the social aspect of the relation in question.
The same thing may be said of another domain of collective mentality: that is, of the feelings involved in parental kinship. The type of feelings underlying this relationship may vary with the society, in the same way as these feelings vary with each individual case in any given society. And as these feelings essentially determine the character of parental kinship in any given society, it appears that the discussion of this point cannot be omitted. Thus into the general formula of kinship there must enter also the psychological elements: collective ideas, expressing in a given society what is kinship, what are its legal, moral and customary aspects; and the collective feelings prevailing in a given society. From the interaction of these psychological elements with different variable social elements arise the more special, peculiar factors which define kinship in any given society. In other words, the variable elements in the general formula of kinship are seen to arise chiefly from the collective psychological interpretation and valuation of some of the physiological and social facts underlying parental kinship.
To sum up, it may be said that parental kinship is the personal tie obtaining between members of the parental group or individual family, and like all other personalties it must be further determined in each society by the characteristic collective feelings and collective ideas which in the given society give it its specific meaning.[518] This is that general formula of kinship which will yield us what we have demanded of it—that is, an indication of the facts for which to look in any given society. As the facts referred to in the first part of the above definition (the establishment of the existence of the family unit) are dealt with in the remaining chapters, it is necessary to discuss only the second part of the definition.
The influence upon kinship of the beliefs and ideas as to procreation appears quite plainly upon an analysis of the concept of consanguinity, and to this we may devote a few words.
Parental kinship is in our society conceived invariably and exclusively in terms of consanguinity,[519] or, speaking more explicitly, parental kinship is conceived as established by the tie of common blood, resulting from birth (maternal kinship) or procreation (paternal kinship). Of course the mere physiological fact does not establish kinship in its full extent, with all its personal, emotional, social and legal aspects. It is only when the physiological facts of procreation or birth are sanctioned by society, in other words when they are consummated in legal marriage, that the children are full kinsmen of both their parents. Society takes all facts which are of vital importance for itself under its own supervision; and consequently the important facts of propagation are subject to the control of society, which regulates them by a series of religious, legal, customary and conventional norms, all of which are also necessary conditions and essential features of full parental kinship. But this sanction once granted, the tie of common blood is conceived as the main source of all mutual duties and moral and legal obligations; and from this also outflow the feelings of love, attachment, reverence, and so forth, which are in our society the essential features of parental kinship. Once a man knows that a child, which he considered his own, is in reality not begotten by him, undoubtedly all his feelings for this child are affected, and, under certain conditions, its legal position may be modified. The two conditions for full parental kinship in our society are (1) that the child be the real physiological offspring of both presumed parents; (2) that it be legally begotten or its birth legalized.
In our society the line of distinction between physiological consanguinity and social consanguinity is quite clear; the one is a mere physiological fact,[520] the other the social acknowledgment of this fact and all its consequences, subject to certain norms, laid down by society.
There are two separate sets of circumstances in which we may speak of consanguinity: (1) the existence of social institutions, which allow us to trace the physiological blood ties (e. g. monogamy or harem institutions), in which case we can speak of the existence of physiological consanguinity as obtaining between the members of the individual family. (2) The existence of a social acknowledgment of the facts of procreation as creating ties of individual personal kinship, in which case we may speak of social consanguinity. If neither of these conditions are fulfilled, then it would be quite meaningless to speak of consanguinity.[521]
Now let us see whether these conditions are to be found in all human societies. That both are found in the majority of the more highly developed societies appears beyond doubt. But this seems not to be the case in the lower societies. Even a superficial glance at them is sufficient to prove it. Whereas, in some of the lowest peoples known conjugal fidelity seems to be the rule,[522] and consequently the physiological tie of blood between children and both their parents is secured, in other societies of low culture the sexual laxity is so great that there is no possibility at all of tracing the descent of a child from any individual man.[523] This applies in the first place to the majority of the Australian tribes, as is shown in the chapter on sexual matters. In consequence, it may be said that in many low societies, and especially in some of the Australian tribes, there is no possibility of speaking of physiological consanguinity as regards the father.
How does the case stand with the social importance attributed to the facts of procreation? Here the variation seems to be still greater. This can be very well exemplified by the Australian material. Over the greater part of the continent the father's share in procreation is not known. There cannot be any social acknowledgment of it. Consanguinity in its social sense does not exist. In some tribes of South-East Australia, on the other hand, the mother's share in procreation is under-rated; the father is considered to be the only consanguineous relative; the child is the father's offspring only, the mother being merely its nurse. Here the consanguineous relation between mother and child is considerably reduced in social importance, and consanguinity as it appears to the social mind is purely paternal. It may be said, therefore, that paternal kinship in the Centre and the North of the continent and maternal kinship in the South-Eastern tribes cannot be called consanguinity (in the social sense of this word), although in both cases very close kinship exists, as will appear from a detailed discussion hereafter.