The same ideas about the Latin character of the barbarian language were held by the Greeks.
They called the Romans barbarians, not because they were inferior to the Geeks in civilization, but because they belonged by origin and language, to the family of the barbarian peoples.
“The Greeks”, writes Pliny, “call us barbarians also, and insult us with words much more disgusting than they do the Opicii” (XXIX. I. 14).
The Pope Nicolas I says the same in a letter addressed in 865ad to the Byzantine emperor Michail III, that the Greeks called the Latin language a barbarian and Scythian language (Du Cange, Gloss. Med. lat.; Jaffe, Regesta Pontif. Rom. p. 247).
In the history of Polybius, the Romans figure under the name barbarians (Hist. lib. IX. 38, 5, 7).
Dionysius of Halikarnassus calls the Sicilians a barbarian people, barbaroi Sicheloi (lib. II. 1), and according to Diodorus Siculus, the language of the ancient Sicilians was a barbarian language (lib. V. 6. 5).
Not only the Greeks, but also the Roman authors of classical times considered the popular or rustic Latin language as a barbarian language.
Plautus (2nd century ad) calls Nevius “poetam barbarum” (Mil. Glor. II. 258) and uses the words Barbaria for Italy and barbaricae urbes for the Italians.
Quintilianus writes: “it happens often that the mob in the theaters and circuses exclaim in the barbarian language” Inst. I. 6), meaning rustic. Cicero also calls barbaries domestica the rustic language spoken in the houses of the Roman citizens (Brutus, s. 74).
The citizens of Brundusium, writes Gellius, had brought from Rome a teacher of Latin language; but this one read Virgil in a barbarian and ignorant mode (Noct. Att. XVI. 6; Cicero, Tusc. II. 4).
The barbarian language had therefore, according to Roman authors, the characteristics of the vulgar or rustic Latin language.
Gellius also states that the barbarian language was the same as the rustic Latin language. “When we say today”, writes he, “that somebody speaks a barbarian language, it is nothing else but the rustic language” (XIII. 6).