In starting to read The Decline and Fall of the Roman Empire by Gibbon, I came across this in the intro by Hugh Trevor-Roper. I think it's worth contemplating.

Public Virtue 'which among the ancients was denominated patriotism, is derived from a strong sense of our own interest in the preservation and prosperity of the free government of which we are members. Such a sentiment, which had rendered the legions of the Republic almost invincible, could make but a very feeble imporession on the mercenary servants of a despotic prince.' ...

For virtue, to Gibbon, is not, as to the Stoics, merely a private possession, enabling a man to bear with equanimity all the blows of fortune. It is essentially an active principle. It depends on freedom, demands freedom, and creates freedom. It also, since it nourishes science, forwards material progress. Conversely, monopoly of any kind is its enemy: monopoly of power, monopoly of wealth, monopoly of knowledge or of alleged access to truth. The centralized power of the imperial bureaucracy was on such impediment to virtue: by its mere structure 'the empire of the Ceasars undoubtedly checked the activity and progress of the human mind.' The vast hereditary estates of the Roman landlords were another. So was the immobility of labour - the hereditary obligation of the Roman middle class as much as the hereditary serfdom of the early medieval peasant. Gibbon hated all forms of immobilization: mortmain of land, thesaurization of wealth, tied labour. So he would rejoice when the Crusades incidentally broke up baronial wealth and power and would record without pain the sacrilegious dispersal of clerical wealth, 'most wickedly converted to the service of mankind.'

Public Spirit, public service - this, to Gibbon, was the human motive force of progress; and it was nourished, in his view, by the kind of society which, in turn, it created and preserved: a plural, mobile society. It had created the city-states of Greece, the republic of Rome; and from those city-states and that Republic - not from the Roman Empire - the ideas had been born which were the intellectual means of is preservation. The centralization, the immobility, the monopoly of the Roman Empire had gradually destroyed that pluralism, stifled those ideas, and so progress had been retarded, public virtue had declined, and in the end an inert, top-heavy political structure had fallen to external blows which a healthier organism could have survived. For it was not the barbarians - 'those innocent barbarians' - who had destroyed the Western Empire. 'If all the barbarian conquerors had been annihilated in the same hour, their total destruction would not have restored the empire of the West.' It had been rotted from within.