166 THE SOCIAL THEORY OF GEORG SIMMEL

The Gradualness of Change

More important for the persistence of the group unity
is the physiological concatenation of successive generations
 and the element of kinship. The significance of this
factor lies in the fact that the displacement of one generation
 by the following does not take place all at once. The
number of individuals that leave and enter the group at
any given time is relatively small compared to the number
of those that remain. The change takes place so gradually
that the group persists as a unit in a manner not unlike
that in which the organism persists in spite of the change
in its cells.
This physiological concatenation and the fact of inheritance,
 which is immediately related to it, are practically
the only factors in modern times which preserve the family
in the larger sense. Of all the elements that formerly contributed
 to the persistence of the family, such as occupation,
 religion, tradition, etc., only the physiological factor
remains.
The gradualness of this change and its contribution to
the persistence of the group unity is most evident in case
the latter rests on procreation. But the same form of
change occurs in cases where the physical agency is excluded.
 The Catholic clergy is an illustration of such a
case. Here the continuity is secured by the fact that
enough individuals are in office at a certain time to initiate
the neophytes. The physiological basis gives place to a
psychological one. The old members belonging to the
group at any given moment separate from the organization
 only after the new members have been fully assimilated
 to the form and the spirit of the group. It is this fact
that makes bureaucracies so tenacious and that preserves
their character and spirit in spite of all the shifting of individuals.
 The persistence of this kind of group depends,