It shows itself in the gradual sinking back of an economy based upon free exchange into more and more primitive conditions when every province seeks to be self-sufficient and barter takes the place of trade.

It shows itself in the decline of farming and in the workless city population kept quiet by their dole of bread and their circuses, whose life contrasted so dramatically, so terribly with that of the haughty senatorial families and the great landowners in their palatial villas and town houses.

It shows itself in the rise of mystical faiths on the ruins of philosophy, and of superstition (more especially astrology) on the ruins of reason.

One religion 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.