The Matter even of the Intellectual Realm is the Indefinite, [the undelimited]; it must be a thing generated by the undefined nature, the illimitable nature, of the Eternal Being, The One illimitableness, however, not possessing native existence There but engendered by The One. Enneads: II IV. 15
Matter, then, must be described as Indefinite of itself, by its natural opposition to Reason-Principle. Reason is Reason and nothing else; just so Matter, opposed by its indeterminateness to Reason, is Indeterminateness and nothing else. Enneads: II IV. 15