200 THE SOCIAL THEORY OF GEORG SIMMEL 
An example of this correlation is manifest in the history 
of the guilds. Originally the guild prescribed stringent 
rules and required absolute uniformity of trade activities 
on the part of all members. Later it became impossible 
to maintain this condition of undifferentiated uniformity. 
The master who had become prosperous refused to be 
bound within the narrow limits of guild regulations. When 
he finally secured the right to employ more journeymen 
and to sell articles not manufactured in his own shop, there 
resulted two important changes. On the one hand, the 
originally homogeneous group of guild members differen- 
tiated into rich and poor, capitalists and workers, traders 
and craftsmen, and the possibility of unfolding personal 
characteristics led to an increased differentiation and spe- 
cialization. On the other hand, there followed a great exten- 
sion of the market and a great increase in the number of cus- 
tomers. The differentiation of the functions of merchant 
and craftsman gave the former a greater freedom and per- 
mitted him an extension of business relations which had 
been impossible under former conditions. 
This division of labor which appears in correlation with 
the extension of the group is not confined to the content 
of the activity, but it also manifests itself in a sociological 
direction. As long as a group is self-sufficient, there exists 
at least this similarity, even in case of professional speciali- 
zation, that the service of each individual is functionally 
related to the group. This service has from the sociological 
point of view a centripetal direction. When the group 
ceases to be self-sufficient and begins to trade with other 
groups, there occurs within the group a differentiation be- 
tween those who work for internal consumption and those 
who work for foreign trade. 
The same correlation is manifest in numerous other de- 
velopments and situations. With the decline of the feudal