has always been
the case from the beginning of the world, and will always be the case.
To understand what society is, either in its larger or its smaller
parts, and why it is so, and how far it is possible to make it
different, we must invariably explain groups on the one hand, no less
than individuals on the other. There is a striking illustration in
Chicago at present (summer, 1905). Within a short time a certain man has
made a complete change in his group-relations. He was one of the most
influential trade-union leaders in the city. He has now become the
executive officer of an association of employers. In the elements that
are not determined by his group-relationships he is the same man that he
was before. Those are precisely the elements, however, that may be
canceled out of the social problem. All the elements in his personal
equation that give him a distinct meaning in the life of the city are
given to him by his membership in the one group or the other. Till
yesterday he gave all his strength to organizing labor against capital.
Now he gives all his strength to the service of capital against labor.

Whatever social problem we confront, whatever persons come into our
field of view, the first questions involved will always be: To what
groups do these persons belong? What are the interests of these groups?
What sort of means do the groups use to promote their interests? How
strong are these groups, as compared with groups that have conflicting
interests? These questions go to one tap root of all social
interpretation, whether in the case of historical events far in the
past, or of the most practical problems of our own neighborhood.

2. The Unity of the Social Group[91]

It has long been a cardinal problem in sociology to determine just how
to conceive in objective terms so very real and palpable a thing as the
continuity and persistence of social groups. Looked at as a physical
object society appears to be made up of mobile and independent units.
The problem is to understand the nature of the bonds that bind these
independent units together and how these connections are maintained and
transmitted.

Conceived of in its lowest terms the unity of the social group may be
compared to that of the plant communities. In these communities, the
relation between the individual species which compose it seems at first
wholly fortuitous and external. Co-operation and community, so far as it
exists, consists merely in the