[xaritas]

As Horace wrote around 14 BC:

Graecia capta ferum victorem cepit et artes intulit agresti Latio. - Ep. II.i.156

"Greece, once conquered, herself conquered the artless victor, and planted the banner of civilization in the farmlands of Rome."

I have translated freely and taken considerable license.

By Aurelius' time, familiarity with Greek for the ruling classes was a given; as a matter of preference, it is a more supple language and probably more comfortable to use for putting abstract reasoning to words.