It is a tragedy, perhaps, that the Roman model was abandoned. The modern era, for all its material comforts, is perhaps incapable of returning to it. The Roman model of ‘diversity’ sought not to emphasise ethnic differences, but to relegate them to a secondary and ultimately inconsequential status. For a while, all that really mattered was that one aspired to the status of civis Romanus. Roman diversity also required something that the modern West is incapable of providing: a critical, but in the end self-assured and even triumphalist vision of its own history, and with it a belief in the value of one’s own society and the ability to make membership of that society a desirable end in itself. The modern West is fractured, and just as in the Rome of third and fourth centuries pleas to encompassing civic virtues seem to hold less appeal in the face of fragmentation and conflict. We cannot, and should not follow the Romans in all matters, but we might learn something valuable if we take their emphasis on a universal and aspirational mode of civic participation seriously.
http://quillette.com/2017/08/22/yes-romans-diverse-not-way-understand/
Acerbity [əˈsɜːbɪtɪ] 