In this early treatise, Plotinus works out his signature account of matter, by which he distinguishes himself not only from his Presocratic, Aristotelian, and Hellenistic predecessors but also ultimately from subsequent Neoplatonists. As the alternative title ‘On the Two Kinds of Matter’ given by Porphyry in his Life of Plotinus (§4 and §24) already indicates, Plotinus divides his attention here between intelligible matter (§§2–5) and sensible matter (§§6–14). Particularly distinctive is Plotinus’ identification of sensible matter with privation and non-being, and especially with evil, which Proclus was to reject centuries later in his treatise On the Existence of Evils.
§1. Everyone agrees that matter is the substrate of forms, but there is disagreement about whether matter is corporeal or not, whether it is substantial or not, and whether there is intelligible matter.
§2. Plotinus begins his investigation into intelligible matter. Some preliminary obstacles to the existence of intelligible matter are stated.
§3. Indefiniteness is not an obstacle to the existence of intelligible matter, since matter in the intelligible world will always have all forms.
§4. Intelligible matter would seem to be necessary in order to account for the fact that the intelligible cosmos is both many and one, and for the fact that its image, the sensible cosmos, has both form and matter.
§5. Those who declare matter to be substantial are correct in a way. For intelligible matter may be considered to be substantial insofar as it is illuminated and possesses intellectual life. Intelligible matter is eternal but generated.
§6. Plotinus turns to examine sensible matter. Reflecting on the generation and destruction of sensible bodies shows that there must be sensible matter.
§7. A critique of Presocratic theories of sensible matter.
§§8–9. Sensible matter is incorporeal and without quality. Neither does it possess quantity or magnitude, which are delivered to matter by whatever form it receives.
§10. Despite matter’s lack of determination, we do have epistemological access to it. This is possible by a kind of dim thinking or spurious reasoning.
§11. Matter is not to be confused with mass, even if it appears to be mass when we try to imagine it.
§12. Although actions are in the sensible world without requiring matter, matter is required for quality, magnitude, and corporeality.
§§13–14. Matter is not a quality. Matter and privation are one in substrate but two in account.
§15. Both intelligible and sensible matter are unlimitedness, and not merely in an accidental manner, and sensible matter is more truly unlimited than intelligible matter.
§16. Whereas intelligible matter is Being, sensible matter is poverty of goodness and exceedingly evil.