Explanation: Both the Roman Empire and Han China adhered to a remarkably similar dichotomy in which everyone was either civilized (ie part of and acceptable to the ruling culture) or a filthy barbarian. This, at first, may sound intuitive, especially as we in the modern day are brought up in a culture of civic and cultural nationalism sprouting from the 19th century AD, but it's actually somewhat unusual in the time period - both the Romans and the Han Chinese viewed the important signifier of civilization not as residence, power, or descent, but the practice of the 'correct' cultural norms and customs. Of particular note is that the Roman use of 'barbarian' held weaker essentialist connotations than the original Greek term it was derived from - people were not born barbarians, they were made barbarians by their inferior cultural circumstances.

As such, their condemnation of outsiders as barbarians was both welcoming, and yet, arrogant - welcoming because it necessarily extended the possibility of civilization to others, no matter how far-flung or how distant the common descent between peoples - arrogant because it denigrated literally everyone who refused to be Roman/Han Chinese as part of a lesser, savage state of being. What barbarians! Dohohohohoho!