It is in Christian writers alone that we find the vigour of life. The earliest work of Christian apologetics is the _Octavius_ or Minucius Felix, a contemporary of Fronto. It is written in pure Latin and is strongly tinged by classical influences. Quite different is the work of "the fierce Tertullian," Q. Septimius Florens Tertullianus (c. 150-230), a native of Carthage, the most vigorous of the Latin champions of the new faith. His style shows the African revolt of which we have already spoken, and in its medley of archaisms, Graecisms and Hebraisms reveals the strength of the disintegrating forces at work upon the Latin language. A more commanding figure is that of Aurelius Augustinus or St Augustine (354-430), bishop of Hippo, who for comprehensiveness and dialectical power stands out in the same way as Hieronymus or St Jerome (c. 331 or 340-420), a native of Stridon in Dalmatia, does for many-sided learning and scholarship.
The decline of literature proper was attended by an increased output of grammatical and critical studies. From the time of L. Aelius Stilo Praeconinus, who was the teacher of Varro and Cicero, much interest had been taken in literary and linguistic problems at Rome. Varro under the republic, and M. Verrius Flaccus in the Augustan age, had busied themselves with lexicography and etymology. The grammarian M. Valerius Probus (c. A.D. 60) was the first critical editor of Latin texts. In the next century we have Velius Longus's treatise _De Orthographia_, and then a much more important work, the _Noctes Atticae_ of Aulus Gellius, and (c. 200) a treatise in verse by Terentianus, an African, upon Latin pronunciation, prosody and metre. Somewhat later are the commentators on Terence and Horace, Helenius Acro and Pomponius Porphyrio. The tradition was continued in the 4th century by Nonius Marcellus and C. Marius Victorinus, both Africans; Aelius Donatus, the grammarian and commentator on Terence and Virgil, Flavius Sosipater Charisius and Diomedes, and Servius, the author of a valuable commentary on Virgil. Ambrosius Macrobius Theodosius (c. 400) wrote a treatise on Cicero's _Somnium Scipionis_ and seven books of miscellanies (_Saturnalia_); and Martianus Capella (c. 430), a native of Africa, published a compendium of the seven liberal arts, written in a mixture of prose and verse, with some literary pretensions. The last grammarian who need be named is the most widely known of all, the celebrated Priscianus, who published his text-book at Constantinople probably in the middle of the 5th century.