Roman citizenship, feeling it a privilege and an obligation to be a Roman citizen, confident of their rights under the Roman law and willing to make sacrifices in the name of Rome. The prestige of Rome as of something just and great and law- upholding spread far beyond the Roman boundaries. But even as early as the Punic wars the sense of citizenship was being undermined by the growth of wealth and slavery. Citizenship spread indeed but not the idea of citizenship.
The Roman Empire was after all a very primitive organization; it did not educate, did not explain itself to its increasing multitudes of citizens, did not invite their co-operation in its decisions. There was no network of schools to ensure a common understanding, no distribution of news to sustain collective activity. The adventurers who struggled for power from the days of Marius and Sulla onward had no idea of creating and calling in public opinion upon the imperial affairs. The spirit of citizenship died of starvation and no one observed it die. All empires, all states, all organizations of human society are, in the ultimate, things of understanding and will. There remained no will for the Roman Empire in the World and so it came to an end.
But though the Latin-speaking Roman Empire died in the fifth century, something else had been born within it that was to avail itself enormously of its prestige and tradition, and that was the Latin-speaking half of the Catholic Church. This lived while the empire died because it appealed to the minds and wills of men, because it had books and a great system of teachers and missionaries to hold it together, things stronger than any law or legions. Throughout the fourth and fifth centuries A.D. while the empire was decaying, Christianity was spreading to a universal dominion in Europe. It conquered its conquerors, the barbarians. When Attila seemed disposed to march on Rome, the patriarch of Rome intercepted him and did what no armies could do, turning him back by sheer moral force.