522
Social Aspects
[CH. XV
from the towns for service, and if a 'collegiatus' enlisted and was discovered he was sent back. The fixity of the grades of society naturally intensified the need to employ barbarian forces.
But here our survey, which strictly deals with the cities as affected by historic movements, must find its conclusion. Enough has been said to show that the very life-blood of ancient civilisation was in the cities, and that the civilisation itself was bound to die when this life blood was drained away. In this tragedy of ruin it is difficult to assign any great rôle to human will. No movement in history wears more the appearance of a destiny, sweeping along in an ever growing flood, imperious and irresistible.
