INTRODUCTION TO SOCIOLOGY 67
On the other hand, along the Danube there are seven legions in the place of four, and in the Orient eight in the place of six.
At the beginning of the second century the emperors were busy consolidating the frontiers. The movement toward expan- sion seems to have attained its extreme limit. The vallum Hadriani is built between the Solway and the Tyne, the vallum Antonini between the Clyde and the Forth. The limes of the Rhine is fortified like that of Rhsetia. The rivers are thus not themselves the barriers against the barbarians; it is neces- sary to add to them a human force. The frontier therefore always presents the physical and human combination which is fundamentally the basis of every social phenomena. It is a social phenomenon, not purely physical nor purely human. It is nothing else than social.
If the empire is from this moment on the defensive, it is the intermediate stage between full development and decline. The frontiers are closed. Interior commerce suffers. Infiltration of barbarians takes place irresistibly, in spite of everything, and it prepares the way for the violent removal of the barriers. The establishments of military colonies, of Germanic or other origin, becomes more common. The empire under Constantine (324- 37) moves its capital to Byzantium. At the beginning of the fifth century, in accordance with the notitia dignitatum, it is divided into four prefectures: that of the East, of Illyria, of Italy, and of Gaul ; with fourteen dioceses and one hundred and twenty provinces. Duces and comites are charged with command at the frontiers. In the interior large private proprietorship is developed and strengthened more and more at the expense of small ownership and of the public domain. The forms of dis- memberment and of the feudal hierarchy begin to be prepared. The dismemberment and the feudal regime would have occurred without the invasions of the barbarians. The latter, however, everywhere accentuated the military character of the process. If the external frontiers were removed, we must attribute it in large part to the transformation of internal forces, but always as we have shown, in their external equilibration, which could not be sudden, but adjusted itself slowly and gradually, like all the
