It is not clear how early Latin began to be used as the official language of the Church, but everything points to an important change soon after the middle of the second century. Before that time, Justin, living at Rome, and writing (A.D. 138), for the Roman people to read, a defence of Christianity, which was addressed to the emperor Antoninus Pius, wrote it in Greek; but before long another apologetic writer, Minucius Felix, wrote in Latin. This coincides with other indications to mark a great transition in the latter half of the second century. Up to this time two languages were in literary currency, a foreign scholastic language and an æsthetic vernacular. It was chiefly the wealthy class that sustained these literary languages in Rome. When in A.D. 166 the Oriental plague was brought to Italy with the army returning from Parthia, cultivated society was wrecked, and the literary movement was greatly interrupted in both languages. This was a blow to the artificial culture of Greek in Italy, just as the plague of 1349 and following years was a blow to the artificial culture of French in England. After A.D. 166 a check was given to progress, which lasted, in the secular domain, until the sixteenth century.
Let us spend a moment upon the sequel of the old literature, before we come to the new, which is our proper subject here.
Under the altered times that now ensued, the continuity of classicism is seen in two forms of literature--namely, philological criticism and poetry. The acknowledged model of Latin poetry was Virgil, and his greatest imitator was Claudian, who had made himself a Latin scholar by study, much as the moderns do. Claudian is commonly called the last of the heathen poets. He has also been called the transitional link between ancient and modern, between heathen and Christian poetry.[2] One characteristic may be mentioned, namely, his personification of moral or personal qualities, a sort of allegory destined to flourish for many centuries, of which the first mature example appears in the "Soul's Fight" of Prudentius, the Christian poet, who was a contemporary of Claudian. The school study of the classics produced grammars, and two authors became chiefly celebrated in this branch, namely, Donatus and Priscian. Their books were standards through the Dark and Middle Ages.[3]