of hostility, which forces itself sometimes upon
psychological observation, and in various forms. In the first place, it
appears as that natural enmity between man and man which is often
emphasized by skeptical moralists. The argument is: Since there is
something not wholly displeasing to us in the misfortune of our best
friends, and, since the presupposition excludes, in this instance,
conflict of material interests, the phenomenon must be traced back to an
a priori hostility, to that _homo homini lupus_, as the frequently
veiled, but perhaps never inoperative, basis of all our relationships.

3. Types of Conflict Situations[208]

a) _War._--The reciprocal relationship of primitive groups is
notoriously, and for reasons frequently discussed almost invariably, one
of hostility. The decisive illustration is furnished perhaps by the
American Indians, among whom every tribe on general principles was
supposed to be on a war footing toward every other tribe with which it
had no express treaty of peace. It is, however, not to be forgotten that
in early stages of culture war constitutes almost the only form in which
contact with an alien group occurs. So long as inter-territorial trade
was undeveloped, individual tourneys unknown, and intellectual community
did not extend beyond the group boundaries, there was, outside of war,
no sociological relationship whatever between the various groups. In
this case the relationship of the elements of the group to each other
and that of the primitive groups to each other present completely
contrasted forms. Within the closed circle hostility signifies, as a
rule, the severing of relationships, voluntary isolation, and the
avoidance of contact. Along with these negative phenomena there will
also appear the phenomena of the passionate reaction of open struggle.
On the other hand, the group as a whole remains indifferently side by
side with similar groups so long as peace exists. The consequence is
that these groups become significant for each other only when war breaks
out. That the attitude of hostility, considered likewise from this point
of view, may arise independently in the soul is the less to be doubted
since it represents here, as in many another easily observable
situation, the embodiment of an impulse which is in the first place
quite general, but which also occurs in quite peculiar forms, namely,
_the impulse to act in relationships with others_.

In spite of this spontaneity