and the spiritual supremacy of Rome to bring these communities into a
common relation, as her legions had done before. As the feudal bonds
grew into national autonomies, and Christianity worked the amelioration
of manners, brought forth the knowledge that during the dark days she
had hidden, bound the threads of peaceful union in her all-pervading
organization, and taught association in her religious orders, a greater
progress became possible, which, as men have been brought into closer
and closer association and co-operation, has gone on with greater and
greater force.

But we shall never understand the course of civilization, and the
varied phenomena which its history presents, without a consideration of
what I may term the internal resistances, or counter forces, which arise
in the heart of advancing society, and which can alone explain how a
civilization once fairly started should either come of itself to a halt
or be destroyed by barbarians.

The mental power, which is the motor of social progress, is set free by
association, which is,--what, perhaps, it may be more properly
called,--an integration. Society in this process becomes more complex;
its individuals more dependent upon each other. Occupations and
functions are specialized. Instead of wandering, population becomes
fixed. Instead of each man attempting to supply all of his wants, the
various trades and industries are separated--one man acquires skill in
one thing, and another in another thing. So, too, of knowledge, the body
of which constantly tends to become vaster than one man can grasp, and
is separated into different parts, which different individuals acquire
and pursue. So, too, the performance of religious ceremonies tends to
pass into the hands of a body of men specially devoted to that purpose,
and the preservation of order, the administration of justice, the