Concept
ἕνωσις · henōsis
Henōsis (ἕνωσις) means union, a making-one, from hen (ἕν), 'one', and the verb henoō, 'to unify'. In Neoplatonism it names the summit of the soul's journey: its mystical union with the One, the first principle of all, in an embrace beyond thought, speech, and even being.
Henōsis is the goal toward which the whole Plotinian ascent is ordered. The soul rises by purification and by contemplation through Intellect; but the final step lies beyond contemplation itself, for to contemplate is still to have an object set over against oneself, and the One is beyond all such division. In union the very distinction of knower and known falls away, and the soul, no longer seeing the One as another, is simply one with it. Plotinus called it a touching, a presence, a being-at-home; Porphyry reports that his master reached it four times in the years they were together.
Because it cannot be described from outside, the tradition speaks of henōsis only in images and denials — the flight of the alone to the Alone, the wave that returns to the sea, the center that coincides with the center. It is the practical and spiritual fulfillment of the metaphysics of the One and of return: all things flow from unity and long to be one again, and in the soul that longing can, at the last, be answered.