lowed to marry a squaw of his own clan, though
there might be no blood, relationship between them. If an Algonkin
married a girl of his clan he committed a crime for which his nearest
relatives might put him to death. This law has prevailed widely among
the wild races in various parts of the globe. McLennan, who first
called attention to its prevalence and importance, called it exogamy,
or marrying-out.

What led to this custom is not known definitely; nearly every
anthropologist has his own theory on the subject.[134] Luckily we are
not concerned here with the origin and causes of exogamy, but only
with the fact of its existence. It occurs not only among barbarians of
a comparatively high type, like the North American Indians, but among
the lowest Australian savages, who put to death any man who marries or
assaults a woman of the same clan as his. In some Polynesian islands,
among the wild tribes of India as well as the Hindoos, in various
parts of Africa, the law of exogamy prevails, and wherever it exists
it forms a serious obstacle to free choice--_i.e._, free love, in the
proper sense of the expression. As Herbert Spencer remarks,

"The exogamous custom as at first established [being
connected with capture] implies an extremely abject
condition of women; a brutal treatment of them; an entire
absence of the higher sentiments that accompany the
relations of the sexes."

While exogamy thwarts love by minimizing the chances of intimate
acquaintance and genuine courtship, there is another form of sexual
taboo which conversely and designedly frustrates the tendency of
intimate acquaintance to ripen into passion and love. Though we do not
know just how the horror of incest arose, there can be no doubt that
there must be a natural basis for so strong and widely prevalent a
sentiment.
In so far as this horror of incest prevents the marriage of near
relatives, it is an obstacle to love that must be commended as
doubtless useful to the race. But when we find that in China there are
only 530 surnames, and that a man who marries a woman of the same
surname is punished for the crime of "incest"; that the Church under
Theodosius the Great forbade the union of relatives to the seventh
degree; that in many countries a man could not wed a relative by
marriage; that in Rome union with an adopted brother or sister was as
rigidly forbidden as with a real sister or brother;--when we come
across such facts w