To ascertain the influence of physiological ties of blood on this relation in a given society it is needful to know the way in which they present themselves to the aboriginal mind. That is, we must know the collective ideas of a given society on the facts of procreation. Do they know, or do they not know, the father's part in procreation? But this is not sufficient. Even if they know a certain physiological fact, they may not acknowledge its bearing upon kinship, they may attach no importance to its social aspect. So it is with the fact of physiological maternity in the South-East Australian tribes and with paternity in the cases quoted by Dargun. And it happens very often that in peoples where the causal connection between copulation and pregnancy is well known, fatherhood is by no means determined by its physiological aspect. Not only the collective knowledge of the physiological facts, but also the collective attitude towards them, must therefore be taken into consideration.[532] In short, it may be said that _physiological_ consanguinity has no direct bearing upon social facts. [532] Sir Laurence Gomme writes: "There is a wide difference between the mere physical fact of having a mother and father, and the political fact of using this kinship for social organization. Savages who have not learned the political significance have but the scantiest appreciation of the physical fact. The Australians, for instance, have no term to express the relationship between mother and child. This is because the physical fact is of no significance...." (_loc. cit._, p. 232). To define consanguinity in its social meaning, the collective ideas held by a given society on the facts of procreation must be considered. Consanguinity, therefore, is the set of relations involved by the collective ideas under which the facts of procreation are viewed in a given society. And it must be borne in mind that these ideas express not only the purely theoretical views of the social mind on the facts of procreation; they also involve different emotional elements, and especially the social importance given to these facts by society. Consanguinity (as a sociological concept) is therefore not the physiological bond of common blood; it is the social acknowledgment and interpretation of it.