ppears, speaking roughly and generally, a distinct
difference in the relation which these two motor impulses bear to each
other. Among animals generally, economics are comparatively so simple
that it is possible to satisfy the nutritive instinct without putting
any hard pressure on the spontaneous play of the reproductive instinct.
And nearly everywhere it is the female who has the chief voice in the
establishment of sexual relationships. The males compete for the favour
of the female by the fascination of their odour, or brilliant colour, or
song, or grace, or strength, as revealed in what are usually
mock-combats. The female is, in these respects, comparatively
unaccomplished and comparatively passive. With her rests the final
decision, and only after long hesitation, influenced, it seems, by a
vaguely felt ideal resulting from her contemplation of the rivals, she
calls the male of her choice.[48] A dim instinct seems to warn her of the
pains and cares of maternity, so that only the largest promises of
pleasure can induce her to undertake the function of reproduction. In
civilized man, on the other hand, as we know him, the situation is to
some extent reversed; it is the woman who, by the display of her
attractions, competes for the favour of the man. The final invitation
does not come, as among animals generally, from the female; the decision
rests with the man. It would be a mistake to suppose that this change
reveals the evolution of a superior method; although it has developed
the beauty of women, it has clearly had its origin in economic causes.
The demands of nutrition have overridden those of reproduction; sexual
selection has, to a large extent, given place to natural selection, a
process clearly not for the advantage of the race. The changing status
of women, in bestowing economic independence, will certainly tend to
restore to sexual selection its due weight in human development.

In so doing it will certainly tend also to destroy prostitution, which
is simply one of the forms in which the merging of sexual selection in
natural selection has shown itself. Wherever sexual selection has free
play, unhampered by economic considerations, prostitution is
impossible. The dominant type of marriage is, like prostitution, founded
on economic considerations; the woman often marries chiefly to earn her
living; here, too, we may certainly expect profound modifications. We
have long sought to preserve our social balance b