Are you sure? It's my understanding that "barbarus" simply meant "not Greek or Roman" or something like "foreigner" in Classical Latin and that the idea of a barbarian necessarily being uncivilized came later, probably because of the relatively uncivilized Germanic and Hunnic tribes who overran the Western Empire in it's final generations.
For example, Romans would have called the Persians or Chinese barbarians, although both were obviously highly civilized. If I recall correctly, Saint Augustine wrote that it didn't matter if the barbarians conquered the Empire as long as they were Christian and didn't seem to mean the term in a pejorative sense.
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