in particular grew mighty, by clasping its sacred book and addressing itself with words of hope to the victims of social injustice, but although it was able to bring comfort to individuals it could do nothing, indeed it did not try, to give new strength or inspiration to the embattled civilization.  True to its own ethos it was impartial as between Barbarian and Roman, or between the Romans who prospered and ruled and those outside the pale.

The most obvious manifestation of Roman society in decline was the dwindling numbers of Roman citizens.  The Empire was being depopulated long before the end of the period of peace and prosperity which stretched from Augustus to Marcus Aurelius.  Does not Augustus himself summon the poor man of Fiesole who has a family of eight children, thirty-six grandchildren and eighteen great grandchildren, and organize in his honour a fete in the Capitol, accompanied by a great deal of publicity?  Does not Tacitus, half-anthropologist and half-Rousseau, describing the noble savage with his eye on fellow citizens, remark that among the Germans it is accounted a shameful thing to limit the number of your children?  The long duration of Augustus’s legislation to raise the birthrate is significant; successful it was not, but the fact that it was maintained on the statute book and systematically revised and developed for three centuries shows that it was at least accounted necessary.  It is true of course that the mortality rate was a far more important factor in those days than it is in our own, and the mortality from pestilence and civil war from Marcus Aurelius onwards was exceptional.  And it is plain that the proportion of celibates was high in the Roman empire and that the fall in the fertility of marriages was going on.  It is the childless marriage, the small family system that contemporary writers deplore.  In Seeley’s striking phrase:  ’The human harvest was bad,’ It was bad in all classes, but the decline was most marked in the upper ranks, the most educated, the most civilized, the potential leaders of the race.  In the terrible words of Swift, facing his own madness, the Roman Empire might have cried:  ’I shall die like a tree—­from the top downwards.’

Why (the insistent question forces itself) did this civilization lose the power to reproduce itself?  Was it, as Polybius said, because people preferred amusements to children or wished to bring their children up in comfort?  Hardly, for it is more marked among the rich than the poor and the rich can have the best of both worlds.  Was it because people had grown discouraged and disheartened, no longer believing in their own civilization and loath to bring children into the darkness and disaster of their war-shattered world?  We do not know.  But we can see the connection of the falling population with the other evils of the empire—­the heavy cost of administration relatively heavier when the density of the population is low; the empty fields, the dwindling legions which did not suffice to guard the frontier.