questions arise from the action of Mr. Atkinson's
"primal law." His theory offers a solution of the much-debated
question of the origin of exogamy,[34] the term used first by Mr.
McLennan, in _Primitive Marriage_, for the rule which prohibited
sexual relationships within the group limit. Continence imposed by the
patriarch on his sons within the group, as a condition of his
tolerance of their presence, necessarily and logically entailed
marriage without, with women from some other group. This explanation
of exogamy is so simple that it seems likely to be true. It is much
more reasonable than any of the numerous other theories that have been
brought forward. Mr. McLennan, for instance, suggests that the custom
arose through a scarcity of females, owing to the widespread practice
of female infanticide. This can hardly be accepted, for such
conditions, where they exist, would arise at a much later period. Even
less likely is the theory of Dr. Westermarck, who explains exogamy as
arising from "an instinct against marriage of near kin." But we have
no proof of the existence of any such instinct.[35] Mr. Crawley's
view is similar: he connects the custom with the idea of sexual taboo,
which makes certain marriages a deadly sin. It is evident that these
causes could not have operated with the brute patriarch. One great
point in favour of Mr. Atkinson's view is that it takes us so much
further back. By it exogamy as a custom must have been much earlier
than totemism, as at this stage the different group-families would not
be distinguished by totem names; but its action as a law would become
much stronger when reinforced by the totem superstitions, and would
become fixed in rigid sexual taboos.[36] The strongest of these taboos
is the avoidance between brothers and sisters; this is Mr. Atkinson's
_primal law_. It is a law that is still a working factor among
barbarous races, and entails restrictions and avoidances of the most
binding nature.

[34] _Studies._ Chap. VII. "Exogamy: Its Origin."

[35] _History of Human Marriage._ Chap. XIV. "Prohibition of
Marriage between Kindred."

[36] _Mystic Rose._

Unfortunately I have not space to write even briefly on this important
and deeply interesting subject. A right understanding of the whole
question of sexual taboos, with the complicated totem superstitions on
which they are based, is very necessary to any inquiry into the
position of women. But to do this I shou