[1949. In Collier’s Encyclopedia. New York: P.F. Collier and Son.]
PLOTINUS (A.D. 205-270), philosopher and teacher, was born in Egypt, probably in A.D. 205. He studied at Alexandria under the philosopher Ammonius Saccas, took part in a military campaign against the Persians, and in A.D. 244 settled in Rome, where he spent his remaining years. He founded a school in Rome, one of his pupils being the philosopher Porphyry, and brought to its highest development the system of philosophy known as Neo-Platonism. Plotinus died in A.D. 270, at the age of sixty-six. His extant writings consist of fifty-four tractates, arranged by his pupil Porphyry into six enneads, or groups of nine.
For Plotinus, whose interests were strongly psychological, the explanations of man and of the universe proceed in parallel. Man, he maintained, is not a materialistic result of atomic motion; he is a soul. Similarly, inanimate compounds are not chance accretions; there is a world soul, and the determinate proportions of particular things are evidence of a determining Reason. Man, in this view, is not merely the vegetative soul; he is more truly the sensitive soul, and especially the imaginative and remembering soul. These functions of imagining and remembering Plotinus analyzes with acuity. In exercising them at their highest reach, man is in contact with, one may even say man is, Reason. Similarly, as Reason is above the soul of man, above the world soul is the Divine Mind, the analogue of Plato’s world of Ideas. The things of this world are mere reflections of these Ideas, visible images in an invisible mirror.
The Divine Mind is not, for Plotinus, the ultimate principle, for it has duality and distinctness: one Idea is different from another, and the knowing subject is different from the known object. A complete explanation requires a completely unitary principle. Hence, above the Mind is the One, a Simplicity as pure as Parmenides’ Being. Since the One is superior to all duality, and since language and knowledge involve distinctness, the One can be neither described nor known. Man may come into contact with it only by a mystic vision, an ineffable experience. According to Porphyry, Plotinus experienced such a vision four times in his life.
Thus, the ascent from the sensitive soul or the physical world to Reason, the Divine Mind, and at last to the One, is not only a philosophic exercise but a moral purification. G.H.CL.