The One

In Neoplatonism the One (to Hen) is the absolutely first principle, the source of everything that is. Plotinus places it beyond being and beyond Intellect, so utterly simple that no name truly fits it; even to call it 'one' is to point toward it rather than to describe it, since to be one in the ordinary sense would already be to have a property. It is identified with the Good of Plato's Republic, which is said to be 'beyond being' in dignity and power.

Why it must be simple

The reasoning runs from the many to the one. Whatever is composite depends on its parts and so on something prior that unites them; pursue this back and one must arrive at something perfectly simple, dependent on nothing, on which all else depends. That is the One. Because it has no parts, no limit, and no distinction even between knower and known, it cannot be grasped by reasoning, which always divides subject from object.

How it is approached

Since no positive description fits, the One is approached by negation — saying what it is not — a method later called negative or apophatic theology. At the summit the soul lets go even of these denials and is present to the One in a union beyond thought and speech. From the One all else proceeds by emanation, like light from the sun, without the source being lessened, divided, or changed.

The later refinements

Proclus set the henads beneath the One to mediate its power to all things, and Damascius pressed the doctrine further still, asking whether even the One is sayable and positing an ineffable principle beyond it. The whole tradition reads Plato's Parmenides, whose first hypothesis describes a 'one' that in a sense neither is nor is one, as the scriptural warrant for this first principle beyond being.

Hypotheses of the Parmenides

The later Platonists read the second half of Plato's Parmenides as a hidden map of reality. Its first hypothesis — that if the One simply is one, nothing whatever can be said of it, not even that it exists — became the charter of negative theology; its second, in which the One also has being and so spills over into number and difference, was read as the generation of Intellect. Proclus and Iamblichus built entire theologies on this scaffold.

The return

Because the One is the source of all, every soul keeps a trace of it and is drawn to return; the ascent through virtue and contemplation toward a union beyond thought is the practical heart of the Neoplatonic life.