=Origen=, the gifted pupil of Cle’mens the Alexandrian, an ardent Christian philosopher, flourished in the third century. Among his writings, which, including his discourses, were numbered by thousands, are “Commentaries on the Scriptures,” in the preparation of which he was assisted by clerks who wrote in short-hand from his dictation. Origen also replied effectively to CELSUS, an Epicurean philosopher who some years before had attacked Christianity in his “True Story,” a powerful and much-read work of the time. =Neo-Platonism.=—The Academic philosophy, modified by its later professors and wrapped in a veil of mysticism, gave rise to the eclectic school of the Neo-Platonists, which was popular among the learned till the time of Constantine. The seeds of this philosophy were planted by Philo the Jew, mentioned on page 104 as attempting to reconcile Plato’s doctrines with the teachings of the Hebrew Scriptures. AMMONIUS, of Alexandria, was the real founder of Neo-Platonism, which, as it left his hand, was a medley of Plato’s and Aristotle’s tenets harmonized with the leading doctrines of Christianity. Though Ammonius enjoined his disciples to keep the mysteries of his philosophy to themselves, PLOTI’NUS, one of his distinguished pupils, unfolded them in his writings and taught them publicly at Rome, where he went to live 244 A.D. After Plotinus, PORPHYRY became a shining light of the Neo-Platonists; but he was an outspoken opponent of Christianity, maintaining that the world was without beginning, and denying the divinity of our Saviour. His work “Against the Christians” was afterward burned by order of the Roman emperor Theodosius the Great. IAMBLICHUS, a successor of Porphyry, went back to the mystical speculations of Pythagoras, and, taking quite a different view from the early Neo-Platonists, turned his philosophy to the support of paganism. The emperor Julian the Apostate was one of his converts. EUSEBIUS, the learned ecclesiastical historian, bishop of Cæsare’a in the fourth century, was among those who repelled the assaults of Porphyry on the Christian faith. He was a favorite of Constantine, whose life he wrote. =Longinus= (213-273 A.D.) was the greatest critic and most learned philosopher of his age. He studied and taught at Athens, and by reason of his extensive information was styled “the Living Encyclopædia.” The most distinguished of his pupils was Zenobia, queen of Palmyra, a woman of refined tastes and unusual talent. By his advice, she revolted from Rome; overpowered by the emperor Aurelian, 273 A.D., she sought to exculpate herself by throwing the blame upon her counsellor, and Longinus was put to death. Part of this author’s “Treatise on the Sublime” is all that remains of his many works.