Plotinus c. 204 – 270

Plotinus was a 3rd-century philosopher of late antiquity, born in Roman Egypt and active in Rome, where he founded the philosophical school whose teaching is preserved in the Enneads. Edited by his student Porphyry, the Enneads develop a Platonic metaphysics in which all reality emanates from a single ineffable source called the One, through Intellect and Soul, into the perceptible cosmos. Plotinus is regarded as the founder of Neoplatonism, the dominant philosophical current of late antiquity. His thought decisively influenced Christian theology through Augustine, Islamic philosophy through al-Farabi and Avicenna, and the Renaissance Platonists through Marsilio Ficino. The Enneads remain among the most ambitious works of Western metaphysics.

Plotinus (c. 204–270) was the founding figure of Neoplatonism and the most influential philosopher of the late ancient period. Born in Lycopolis in Upper Egypt, he studied with Ammonius Saccas in Alexandria for eleven years, accompanied a Roman military expedition into Persia in 243, and from 245 ran a philosophical school in Rome under the patronage of the senatorial elite. His student Porphyry edited and arranged his philosophical writings into the six Enneads — six sets of nine treatises — that constitute the surviving record of his thought.

Plotinus's metaphysics develops Plato in directions only loosely anticipated by the dialogues. Reality is structured as a hierarchy of three primary hypostases: the One (the absolute principle, beyond being and intellection), the Intellect (Nous, the realm of the Forms grasped in their unity), and the Soul (the principle of life and motion that organizes the natural world). The hypostases proceed from the One by emanation, and the philosophical-religious task of the soul is its return to the One through philosophical contemplation and ethical ascent.

Plotinus's influence on Christian philosophy through Augustine, on Islamic philosophy through al-Kindi and al-Farabi, on the medieval Jewish tradition, and on the Renaissance recovery of Plato is enormous. His direct influence on twentieth-century continental philosophy — Bergson, Deleuze — has restored him to the philosophical mainstream after a long period in which he was treated as a transitional figure rather than as a major philosopher in his own right.