164 THE SOCIAL THEORY OF GEORG SIMMEL
independent of the individuals who compose it. The group
can remain identical while the members change. We still
speak of the same state, the same army, the same association,
 when not a single original member survives. The persistence
 of the group is therefore by no means identical
with the persistence of its members. It is a different phenomenon.
 The members may perish while the group remains,
 and the group may dissolve while the individuals
remain.
At first sight it would seem as if there were a great similarity
 between the phenomenon of group persistence and
that of group existence. But the process of socialization
as it takes place in the temporal order is not fully identical
with the process that takes place in the spatial order. The
group exists at a certain time because the mental bond between
 the individuals overcomes their separation in space.
It is the process of interaction between them that creates
and maintains the unity of the group. But in the case of
individuals separated from one another in time, the group
unity cannot be maintained in the same manner. In that
case a complete reciprocity is impossible. The earlier members
 may indirectly influence the later members, but the
later members cannot influence the earlier ones. Hence the
persistence of the social unity in spite of shifting membership
 presents a peculiar problem which is not solved by explaining
 how the group has come into existence at a certain
 moment.
Among the different factors which contribute toward
this persistence of the group may be mentioned the following:
 the fact that the change in membership occurs only
gradually; the permanence of the locality; the objectivation
 of the group unity in symbols; its protection by means
of law, honor, and morality; and the formation of special
organs. The function of each of these factors and its con-