176 THE SOCIAL THEORY OF GEORG SIMMEL

The first type of social self-preservation is characteristic
 of groups which contain widely divergent elements. If
these divergent elements are not sufficiently integrated and
not adjusted to a harmonious co-operation, there is a danger
 that any change or innovation will drive them farther
apart. That danger is especially great in cases of rigid
social stratification and complete separation between the
social classes. The reason for this is that any change is
likely to begin in one social class, or at least to affect that
one class more immediately and more strongly. If intermediate
 classes exist, the change can spread gradually
through the whole group, extending slowly over wider
circles and at the same time decreasing in intensity. If
such classes fail, the change will attack also the classes
least disposed to it in a much more violent and ruthless
manner. The middle class or classes fulfil the function of
buffers and shock-breakers. They absorb the inevitable
dislocations which result from sudden changes, reduce
them, and distribute them over the whole group. This is
one of the formal sociological reasons why aristocracies,
in so far as they are based on sharp class distinctions, are
also essentially conservative. A social group consisting of
clearly separated castes, or a political combination consisting
 of distinct ethnic groups, is also faced with the same
problem.
A similar conservatism is found in groups or structures
which have lost their actual functional relationship with
the larger social unit. Changes and innovations in the
sociological forms can be borne and sustained only by living
 social forces. Obsolete social structures have long lost
that sustaining force. They persist as empty forms, as hollow
 husks which even the smallest change might destroy
and demolish. The life has gone out of them. The vital organic
 relationships bave disappeared, and they can main-