Nevertheless, there is reason to think that these institutions have not the same origin. For several primitive tribes, some of them inferior in culture to the average Australian, have customs of Exogamy, or (at least) forbidding marriage between individuals of some certain description, who have not, and are not known ever to have recognised Totemism. Many tribes, again, who by their ethnological position may be supposed once to have entertained Totemism, have abandoned it, but still maintain Exogamy by means of Marriage-classes (phratries) or otherwise. Further, many nations of advanced culture cannot be shown ever to have been totemists, but have always (as far back as can be traced) enforced Exogamy so far as to prohibit marriage within certain degrees of kindred. And that the connexion between Totemism and Exogamy is not original but acquired, is indicated by the consideration that the most obvious tendency of Totemism would be to favour Endogamy (the practice of not marrying outside certain limits), on the obvious principle that as an animal kangaroo mates with an animal kangaroo, so a human kangaroo should marry a human kangaroo. This is so obvious that the opposite rule that a human kangaroo must not marry another one, but (zoological paradox!) only an emu or a witchety-grub, seems perverse, and only to be explained by the influence of some superstition or incidental custom. According to Arunta tradition, their ancestors in the Alcheringa were endogamous.

Whether Exogamy originated in the days of the hunting-pack—which is so far probable that the Boschmans observed it—or during the reconstitution of society after the breaking up of the packs, or even later, or in some regions at one period, in others at another, is, I fear, beyond our power of verifiable guessing. The best hypothesis as to the grounds of the custom is Westermarck’s, namely, that an instinct of mutual avoidance grew up between near kin. This requires that at the time of its origination promiscuity of sexual relations should not have prevailed in the human stock, since that would have destroyed the conditions necessary to the rise of such an instinct. If promiscuity was ever widely practised, it must have been after the breaking up of the hunting-packs. That at some stage of human life, and apparently with some Australian tribes not a remote one, promiscuity was established, has been argued (on the ground of some Australian customs) with much plausibility; but in his History of Human Marriage,[529] Westermarck has examined this opinion very carefully, and concludes that it is not tenable. His reasoning seems to me good throughout; and, having nothing important to add to it, I refer the reader to his work.

Whether amongst anthropoids any instinctive avoidance prevails, preventing what we conceive of as incest, nobody knows. With their solitary families, the growth of such a disposition may be more difficult than amongst gregarious animals (such as our ancestors had become long before they could be called “human”), who find other families at hand to intermarry with; though the primitive human bands probably were not large. Savages now at the lowest level, such as the Veddas or Yaghans, rarely form parties of more than thirty or forty. The Boschmans, before their tribal habits were destroyed in the early years of last century, though sometimes assembling in large numbers for the great hunts by means of stockade traps, yet were usually scattered in groups of a few families. It is not likely that their remote forefathers consorted in larger numbers: eight or ten families may have been enough to co-operate in hunting, or in mutual defence. Within each family constituting such a band the tendency to Exogamy may first have manifested itself.

Westermarck’s hypothesis concerning Exogamy was first published in the History of Human Marriage,[530] and has been re-stated in The Origin and Development of Moral Ideas.[531] In the former work he fully discusses the evidence as to the effects of the inter-breeding of near kin, and concludes that it is probably injurious. The evidence is conflicting, but his conclusion seems to me justifiable. And he rightly points out that if, amongst civilised nations, the mischief of inbreeding is not always manifest, it was probably much greater amongst primitive savages: (1) because the blood of the stock was purer; for in modern Europe (e. g.) every marriage brings together many different strains. (2) Because communities were then much smaller; so that under endogamous conditions whatever vice may beset inbreeding would, generation after generation, be perpetuated and exaggerated without relief. It may be added that with Endogamy the young folk are likely to begin to breed earlier—perhaps by two or three years—than they would with Exogamy; and there is no doubt that the marriage of immature individuals is highly injurious to the race.

But if inbreeding was injurious, Natural Selection favoured any family or band that practised Exogamy. That any should have done so on rational grounds, to avoid the observed evil effects of inbreeding, cannot be supposed. The motive must have been blind to the consequences, and may have taken the form of coldness toward those of opposite sex with whom one had grown up from infancy, or of aversion to the idea of marrying them. Such dispositions Natural Selection preserved, and they have descended to ourselves; for such was the beginning of the abhorrence of incest.

I conjecture that this feeling first showed itself within the family, and led the families of a band to exchange their daughters; and that later it extended to all members of the same band, and that wives were then sought from other bands. Probably wives were obtained sometimes by capture or enticement, sometimes by exchange so far as amicable relations with neighbours prevailed: for the evidence is far from showing that “marriage by capture” was ever a general custom; whilst our knowledge of the Australians and Boschmans shows that neighbouring bands of savages are not always hostile.

Such a state of things may have existed for ages before the rise of Totemism, and amongst races that never adopted Totemism. When names of animals were first given to, or adopted by, various groups, Totemism somewhere (perhaps in several places) resulted, as a belief in the magical or spiritual connexion between men and animals of the same name. But the bands that adopted Totemism were already exogamous, having an aversion to marriage with others of the same band; and the practice of Exogamy was thus brought under the mysterious sanction of totemic ideas. It would then be further extended to bar marriage with those of the same Totem in other groups.

Totemic sanctions may have been useful in confirming the Exogamy of some groups, but all superstitious aids to right conduct are liable to perverse issues, and at best they are second best. Totemism prevents consanguineous marriages, but also prevents marriage with thousands of people where no blood-relationship is traceable. If any races were able to perceive that the interest of Exogamy was the prevention of marriage between near kin, and then to keep account of kinship and govern themselves accordingly, they chose the better part.

Some exceptions to the rule that Totem-clans are exogamous may, perhaps, be explained by supposing that certain bands had not adopted Exogamy when they became totemists—may not this have happened amongst the Arunta?—and that they have since learnt Exogamy under other conditions from neighbouring people, or by conquest. Amongst the other possible conditions there are the remarkable Marriage-classes, or phratries that prevail in Australia, North America, and less regularly in other parts of the world. These Marriage-classes are considered by some ethnologists to be of deliberate institution—a reform for the regulation of Exogamy; and Spencer and Gillen, who knew the Australians so intimately, thought such a law—though its intricacy astonishes most Europeans and stumbles many—was not beyond their power of excogitation. Upon that point it would be absurd of me to have any opinion. But to suppose deliberate intention is contrary to the usual method of interpreting savage institutions: a savage language is a system of customs much more intricate and refined than the Marriage-classes, and not generally believed to have originated with the deliberate enactment of rules of grammar. I conjecture that those classes resulted at first from a grouping of exogamous Totem-clans which grew up by custom, and that the only deliberate work consisted in some minor adjustments of clan-relations. Marriage of cousins is prevented in Central and North Australia by the recognition of eight sub-classes; but the same result is obtained in other tribes by a custom which merely forbids it. Exogamous classes having been established in some tribes, may have been imitated in others.