This principle may be very simply stated: Every stronger ethnic or
social group strives to subjugate and make serviceable to its purposes
every weaker element which exists or may come within the field of its
influence. This thesis of the relation of heterogeneous ethnic and
social elements to each other, with all the consequences proceeding
from it, contains within it the key to the solution of the entire riddle
of the natural process of human history. We shall see this thesis
illustrated ever and everywhere in the past and the present in the
interrelations of heterogeneous ethnic and social elements and become
convinced of its universal validity. In this latter relation it does not
correspond at all to such natural laws, as, for example, attraction and
gravitation or chemical affinity, or to the laws of vegetable and animal
life. In order better to conceive of this social natural law in its
general validity, we must study it in its different consequences and in
the various forms which it assumes according to circumstances and
conditions.

2. Social Interaction as the Definition of the Group in Time and
Space[137]

Society exists wherever several individuals are in reciprocal
relationship. This reciprocity arises always from specific impulses or
by virtue of specific purposes. Erotic, religious, or merely associative
impulses, purposes of defense or of attack, of play as well as of gain,
of aid and instruction, and countless others bring it to pass that men
enter into group relationships of acting for, with, against, one
another; that is, men exercise an influence upon these conditions of
association and are influenced by them. These reactions signify that out
of the individual bearers of those occasioning impulses and purposes a
unity, that is, a "society," comes into being.

An organic body is a unity because its organs are in a relationship of
more intimate interchange of their energies than with any external
being. A _state_ is _one_ because between its citizens the corresponding
relationship of reciprocal influences exists. We could, indeed, not call
the world _one_ if each of its parts did not somehow influence every
other, if anywhere the reciprocity of the influences, however mediated,
were cut off. That unity, or socialization, may, according to the kind
and degree of reciprocity, have very different gradations, from the
ephemeral combination for a promenade to the family; from all
relationships "at wi