Longinus was a celebrated philosopher and rhetorician of Athens, who was born about 213 and died in 273 a.d. He traveled widely in his youth, and was for a time a pupil of Ammonius Saccas at Alexandria; but he remained a genuine Platonist, and seems not to have been influenced by the eclecticism of the Neo-Platonists. He was a man of marked ability, of the broadest culture, and a thorough master of Greek style. Of his numerous writings we possess a large part of one beautiful work entitled περὶ ὕψους (often published), and fragments of some others (e.g. in Eusebius’ Præp. Evang. XV. 21). Longinus was the teacher of Porphyry before the latter went to Rome to study under Plotinus. Porphyry has made a mistake in classing Longinus with those other philosophers whose works Origen studied. He was a younger contemporary of Origen, and cannot even have studied with Ammonius until after Origen had left Alexandria. It is possible, of course, that Origen in later life read some of his works; but Porphyry evidently means that the works of all the philosophers, Longinus among them, had an influence upon Origen’s intellectual development. Heinichen reads ᾽Αλβίνου instead of Λογγίνου in his text, on the assumption that Porphyry cannot possibly have written Λογγίνου; but the latter word has the support of all the mss. and versions, and there is no warrant for making the change. We must simply conclude that Porphyry, who, of course, is not pretending to give an exact list of all the philosophical works which Origen had read, classes Longinus, the celebrated philosopher, along with the rest, as one whose works such a student of Greek philosophy as Origen must have read, without thinking of the serious anachronism involved.