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 genera- 
tions and the element of kinship. The significance of this 
factor lies in the fact that the displacement of one genera- 
tion 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 inher- 
itance, 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 con- 
tributed to the persistence of the family, such as occupa- 
tion, 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 ex- 
cluded. 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 organiza- 
tion only after the new members have been fully assimi- 
lated 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 in- 
dividuals. The persistence of this kind of group depends,