classes favored by intergroup struggle, but also the evolution of
morality. The group that could be most efficiently organized would be,
other things being equal, the group which had the most loyal and most
self-sacrificing membership. The group that lacked a group spirit, that
is, strong sentiments of solidarity and harmonious relations between its
members, would be the group that would be apt to lose in conflict with
other groups, and so its type would tend to be eliminated. Consequently
in all human groups we find recognition of certain standards of conduct
which are binding as between members of the same group. For example,
while a savage might incur no odium through killing a member of another
group, he was almost always certain to incur either death or exile
through killing a member of his own group. Hence arose a group code of
ethics founded very largely upon the conceptions of kinship or blood
relationship, which bound all members of a primitive group to one
another.

(5) A final consequence of war among human groups has been the
absorption of weaker groups and the growth of larger and larger
political groups, until in modern times a few great nations dominate the
population of the whole world. That this was not the primitive
condition, we know from human history and from other facts which
indicate the disappearance of a vast number of human groups in the past.
The earth is a burial ground of tribes and natrons as well as of
individuals. In the competition between human groups, only a few that
have had efficient organization and government, loyal membership and
high standards of conduct within the group, have survived. The number of
peoples that have perished in the past is impossible to estimate. But we
can get some inkling of the number by the fact that philologists
estimate that for every living language there are twenty dead languages.
When we remember that a language not infrequently stands for several