As infants cannot learn to speak except by learning words and phrases from those who do speak, why should not men become eloquent without being taught any art of speech, simply by reading and learning the speeches of eloquent men, and by imitating them as far as they can? And what do we find from the examples themselves to be the case in this respect? We know numbers who, without acquaintance with rhetorical rules, are more eloquent than many who have learnt these; but we know no one who is eloquent without having read and listened to the speeches and debates of eloquent men. For even the art of grammar, which teaches correctness of speech, need not be learnt by boys, if they have the advantage of growing up and living among men who speak correctly. For without knowing the names of any of the faults, they will, from being accustomed to correct speech, lay hold upon whatever is faulty in the speech of any one they listen to, and avoid it; just as city-bred men, even when illiterate, seize upon the faults of rustics.
St. Augustine, On Christian Doctrine, Book IV, Ch. 3