group includes the blood relations whom we designate by the corresponding terms, it includes many more, and for social purposes a man does not distinguish between the members of a group who are related to him by blood from those members of the group who are not so related to him. Each man has thus many "fathers" who never begat him, and many "mothers" who never bore him; he calls many men and women his "brothers" and "sisters" with whom he has not a drop of blood in common; and he bestows the names of "sons" and "daughters" on many boys and girls, many men and women, who are not his offspring.
Now, "if we assume, as we have every right to do, that the founders of exogamy in Australia recognised the classificatory system of relationship, and the classificatory system of relationship only, we shall at once perceive that what they intended to prevent was not merely the marriage of a man with his sister, his mother, or his daughter in the physical sense in which we use these terms; their aim was to prevent his marriage with his sister, his mother, and his daughter in the classificatory sense of these terms; that is, they intended to place bars to marriage not between individuals merely but between the whole groups of persons who designated their group, not their individual, relationship, their social, not their consanguineous, ties, by the names of father and mother, brother and sister, and son and daughter. In this intention the founders of exogamy succeeded perfectly. In the completest form of the system, the division of the tribe into eight exogamous classes, they barred the marriage of group brothers with group sisters, of group fathers with group daughters, of group mothers with group sons, and of the sons of group brothers with the daughters of group sisters. Thus the dichotomy of an Australian tribe in its completest form, namely, in the eight-class organisation, was not a clumsy expedient which overshot its mark by separating from each other many
