POETRY AND ROMANCE.--Greek poetry no longer existed at this period. Hardly is it permissible to cite the didactic Oppian, with his poem on sin, and the fabulist Babrius, imitator of Aesop in his fables. In reparation, the romance was born and the scientific literature was important. The romance claimed among its representatives Antonius Diogenes, with his _Marvels Beyond Thule_; Heliodorus, with his _Aethiopica_ or _Theagenes and Chariclea_, the love-story so much admired by Racine in his youth; Longus, with his _Daphnis and Chloe_, which still retains general approval and which possesses real, though somewhat studied grace, and of which the ability of the style is quite above the normal. SCIENTIFIC LITERATURE.--Scientific literature includes the highly illustrious mathematician and astronomer Ptolemy, whose system obtained respect and belief until the advent of Copernicus; the physician Galen; the philosopher-physician Sextus Empiricus, who was a good historian, highly sceptical, but well informed and intelligent about philosophical ideas. DECADENCE OF THE GREEK SPIRIT.--Vitality was slowly withdrawn from the Grecian world, although not without revivals and highly interesting semi-renaissances. In the fourth century, the sophist--that is, the professor of philosophy and of rhetoric--Libanius left a vast number of official or academic discourses and letters which were dissertations. Like his friend the Emperor Julian, he was a convinced pagan, and with kindly but firm spirit combated the Christian bishops, priests, and particularly the monks, who were objects of veritable repulsion to him. He possessed talent of a secondary but honourable rank. THE EMPEROR JULIAN.--The Emperor Julian, a Christian in childhood, but who on attaining manhood reverted to paganism, which earned him the title of "the Apostate," was highly intelligent, pure in heart, and filled with a spirit of tolerance; but he was a heathen and he wrote against Christianity. He possessed satiric force and wit, even a measure of eloquence. A pamphlet by him, the _Misopogon_, directed against the inhabitants of Antioch, who had chaffed him about his beard, makes amusing reading. He died quite young; he would, in all probability, have become a very great man. PROCOPIUS.--It is necessary to advance to the sixth century to mention the historian Procopius, that double-visaged annalist who, in his official histories, was lost in admiration of Justinian, and who, in his _Secret History_, only published long after his death, related to us the turpitude, real or imagined, of Theodora, wife of the Emperor Justinian, and of Antonina, wife of Belisarius.