Romans 1:14

I am a debtor. That is, I am bound to preach the word of God to all. (Witham) --- by Greeks, in this place, are understood the Romans also, and by Barbarians, all other people who were neither Greeks nor Romans. The Greeks called all barbarians, who did not speak the Greek language, even the Latins themselves. But after the Roman became masters of the world, they were excepted, through policy, from the number of barbarians, and particularly after they began to cultivate the science of the Greeks. Græcia victa ferum victorem cepit, et artes

Intulit agresti Latio.

--- St. Paul says, that he is a debtor both to Greeks and barbarians, to the wise, the philosophers, those who pass for sages amongst the pagans, and to the simple, ignorant, unlettered class of mankind: not that he had received any thing at their hands, but because it was his duty, in quality of apostle, to address himself to the whole world, and preach to the great and to the small, to the learned and the unlearned. (Calmet)