Neo-Platonism is the revival and transformation of Platonic philosophy.
Primarily metaphysical with theological emphasis tending toward mysticism, Neo-Platonism started as a synthesis of Pythagoreanism, Platonism, Aristotelianism, and Stoicism, adapted Jewish and Oriental religious elements, crept, though professedly pagan, into patristic Christian theology, and finally influenced medieval and modern thought. Though the term's narrower meaning confines Neo-Platonism to its most potent phase from 200 to 550 A.D., where it was the chief philosophy of classical paganism, whose principal philosophers then were making a last attempt to explain the dualism of appearance and reality, yet its wider significance includes Neo-Platonism's long history, of which perhaps six periods may be suggested:
(1) Preparatory (1st century B.C. to 3rd century A.D.), wherein eclectic philosophers groped syncretically toward Neo-Platonism.
(2) Formulative (3rd century), when appeared the founders: Ammonius Saccas (242), who left no writings, but whose lectures led Plotinus (205-270), his greatest disciple and the sect's first systematic thinker, to supply the most complete corpus of philosophical principles (Enneads) between Aristotle (384-322 B.C.) and St. Thomas Aquinas (1225-1274); and Porphyry (232-304), who, the most prominent of Plotinus' many pupils, excelled all Neo-Platonists both in quantity of production and in quality of style.
(3) Propagative (4th century), when Neo-Platonism created important centers of instruction to counter Christian supernaturalism and monotheism, which opposed pagan philosophy and religion. Among the principal propounders were: Iamblichus (333), who introduced theosophy and magic into the dogma; Sallustius (63), who recorded the sect's religious system; Ambrosius Theodosius Macrobius (400), whose commentary on Cicero's Somnium Scipionis influenced medieval schoolmen.
(4) Scholastic (400-550), wherein philosophical schools (principally at Alexandria and at Athens), before their suppression by Emperor Justinian I ended ancient Neo-Platonism (529), produced many notable Neo-Platonists, among whom were : Hypatia, antiquity's most famous female philosopher, who was murdered by a monk-led mob (415); Proclus (410-485), who, applying Aristotelian logic to Neo-Platonism, was the sect's last eminent savant; Anicius Manlius Severinus Boethius (480-524), last of Roman philosophers and first of scholastic theologians.
(5) Medieval (500-1600), wherein influential presentations of Neo-Platonism survived in such representatives as Dionysius the Pseudo-Areopagite (500), whose vogue was universal; Johannes Scotus Erigena (815-877) , Scotch-Irish theologian; Michael Psellus (1018-1078), Byzantille philosopher; and Marsilio Ficino (1433-1499), Pico della Mirandola (1463-1494), Giordano Bruno (1548-1600), three Italian philosophers.
(6) Modern (after 1600), wherein an attempt to revive Neo-Platonism occurred late in the 17th century among the Cambridge Platonists, whose religious idealism combated scientific materialism. Thereafter inspirational traces appeared intermittently among poets and philosophers, except for Thomas Taylor (1758-1835), who was the last European thorough-going Neo-Platonist.
Neo-Platonism preaches a poetical rather than a philosophical solution to the perennial problem of the dualism of mind and matter. The unity beyond all multiplicity is God, from whom emanates the nous (thought, mind, reason), whence proceeds in turn the world-soul, which in turn produces individual souls and the world of nature.
The nous is likened to light, which, as it recedes from God, grows dimmer by emanation until it ends in darkness, which is matter, essentially plural and evil. The individual soul's only escape from the material world is by purificatory stages, which start with practice of virtues and lead through mystical ecstasies until reabsorption with God is reached. But this is poetry, not philosophy, when rapture is exalted above reason, and in this essential process of Neo-Platonism ancient philosophy abdicates.