Plotinus and the One

Plotinus (c. 204–270 CE), probably born in Egypt, studied philosophy in Alexandria with Ammonius Saccas and later taught in Rome from 244 CE, attracting senators and even the emperor Gallienus. He developed the system historians call Neoplatonism, though he saw himself simply as an interpreter of Plato. At the summit of reality is the One, a source so simple that it is beyond all description and even beyond being.

From the One flows, or 'emanates', Intellect (Nous), which contains the Forms, and from Intellect flows Soul, which animates the physical world. Plotinus compared this to light radiating from the sun without the sun being diminished. Human souls, he taught, can turn inward and ascend back toward the One through philosophy, virtue and contemplation. His student Porphyry edited his writings into six groups of nine treatises, the Enneads. Neoplatonism became the dominant philosophy of late antiquity.