If instead of a divine power some other force has appeared, it should be explained in what this new force consists, for the whole interest of history lies precisely in that force.

History seems to assume that this force is self-evident and known to everyone. But in spite of every desire to regard it as known, anyone reading many historical works cannot help doubting whether this new force, so variously understood by the historians themselves, is really quite well known to everybody.

What force moves the nations?