the subconscious states and instinctive reactions which
rule and bind together the members of a primitive community; what I want
to make clear is that the tribal instincts have above all an isolating
effect. These instincts serve not only as a machinery for binding the
members of a community together, but also as a means of separating them
from all surrounding groups. Within the community this machinery compels
unity of sentiment and of action; it serves to repress schism and
faction. But the tribal machinery is operative only up to the
territorial boundaries of the community. At that limit the tribal
instincts immediately change in their mode of action. The tribal
instincts surround the community with a frontier, across which there is
no peaceful traffic, only robbery and plunder; or at the best covert
enmity. The tribal frontier is also a blood barrier; across it the
tribal instinct forbids any form of peaceful matrimonial exchange or
tribal intermixture. Nothing impressed Darwin so much as the ring of
neutral territory which surrounded the primitive Fuegian settlements.

TRIBAL ISOLATION PROVIDES THE CONDITIONS NECESSARY FOR RACE-BREEDING

The tribal or clannish spirit tends to manifest itself in many forms,
but in all its varieties there is a common factor--that of isolation. At
first sight we are tempted to regard the tribal spirit as part of a
machinery evolved for the protection and survival of a primitive
community, but to any one who has searched for conditions which will
explain the origin of separate races of mankind, the conviction grows
that the tribal spirit is an essential part of Nature's evolutionary
machinery. It was in these isolated cradles of primitive mankind that
Nature nursed and reared new races. When a breeder wishes to produce a
new type of animal, or to preserve a 'sport', his first step is to
isolate the group of animals with which he is to experiment. The
isolated stock becomes the cradle in which he hopes to rear his new
breed. The experimental breeder, in such instances, copies the
conditions which rule in primitive human communities. Under modern
civilization Nature's cradles have been smashed to atoms, but the tribal
instincts which Nature intended for the propagation of new breeds of
humanity have come down to modern man in undiminished force. Hence our
present national and racial troubles.

THE CONDITIONS OF TRIBAL DISINTEGRATION

The tribal spirit, which maintains the unity of