Dionysius Cassius Longinus
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [1]
a noted Greek philosopher and rhetorician, was born probably in Syria, and flourished in the 3d century of our aera. He was educated at Alexandria under Ammonius and Origen, and became an earnest disciple of Platonism. To expound this system and to teach rhetoric, he opened a school at Athens, and there soon acquired a great reputation. His knowledge was immense, and to him was first applied the phrases, often repeated since, "a living library" and "a walking museum." His taste and critical acuteness also were no less wonderful. He was probably the best critic of all antiquity. Flourishing in an age when Platonism was giving place to the semi-Oriental mysticism and dreams of Neo-Platonism, Longinus stands out conspicuously as a genuine disciple of the great master. Clear, calm, rational, yet lofty, he despised the fantastic speculations of Plotinus (q.v.). In the latter years of his life he accepted the invitation of Zenobia to undertake the education of her children at Palmyra; but, becoming also her prime political adviser, he was beheaded as a traitor, by command of the emperor Aurelian, A.D. 273. Longinus was a heathen, but generous and tolerant. Of his works, the only one extant (in parts only) is a treatise, Περὶ Υψους (On the Sublime). There are many editions of it; those by Morus (Leips. 1769), Toupius (Oxford, 1778; 2d edition, 1789; 3d edit., 1806), Weiske (Leipsic, 1809), and Egger (Paris, 1837) being among the best. Translations have been made of it into French by Boileau, into German by Schlosser, and into English by W. Smith. See Ruhnken, Dissertatio de Vita et Scriptis Longini (1776); Smith, Dict. of Gr. and Rom. Biog. s.v.; Chambers, Cyclop. s.v.
The Nuttall Encyclopedia [2]
A learned Greek philosopher, rhetorician, and critic, and eminent in all three departments, being in philosophy a Platonist of pure blood; his fame as a teacher reached the ears of Zenobia, the queen of Pal myra, and being invited to her court he became her political adviser as well as the educator of her children, but on the surrender of the place he was beheaded by order of the Emperor Aurelian as a traitor; he wrote several works, but the only one that survives to some extent is his "Treatise on the Sublime," translated by Boileau (210-273).