Matter is no Soul; it is not Intellect, is not Life, is no Ideal-Principle, no Reason-Principle; it is no limit or bound, for it is mere indetermination; it is not a power, for what does it produce? It lives on the farther side of all these categories and so has no tide to the name of Being. It will be more plausibly called a non-being, and this in the sense not of movement [away from Being] or station (in Not-Being) but of veritable Not-Being, so that it is no more than the image and phantasm of Mass, a bare aspiration towards substantial existence; it is stationary but not in the sense of having position, it is in itself invisible, eluding all effort to observe it, present where no one can look, unseen for all our gazing, ceaselessly presenting contraries in the things based upon it; it is large and small, more and less, deficient and excessive; a phantasm unabiding and yet unable to withdraw – not even strong enough to withdraw, so utterly has it failed to accept strength from the Intellectual Principle, so absolute its lack of all Being. Enneads: III VI. 7
Let us begin with the well-known tenfold division of the Existents, and consider whether we are to understand ten genera ranged under the common name of Being, or ten categories. That the term Being has not the same sense in all ten is rightly maintained. Enneads: VI I. 1
On the other hand, line and surface and body are not called quantities; they are called magnitudes: they become known as quantities only when they are rated by number-two yards, three yards. Even the natural body becomes a quantity when measured, as does the space which it occupies; but this is quantity accidental, not quantity essential; what we seek to grasp is not accidental quantity but Quantity independent and essential, Quantity-Absolute. Three oxen is not a quantity; it is their number, the three, that is Quantity; for in three oxen we are dealing with two categories. So too with a line of a stated length, a surface of a given area; the area will be a quantity but not the surface, which only comes under that category when it constitutes a definite geometric figure. Enneads: VI I. 4
So with the numbers themselves: how can they constitute the category of Quantity? They are measures; but how do measures come to be quantities or Quantity? Doubtless in that, existing as they do among the Existents and not being adapted to any of the other categories, they find their place under the influence of verbal suggestion and so are referred to the so-called category of Quantity. We see the unit mark off one measurement and then proceed to another; and number thus reveals the amount of a thing, and the mind measures by availing itself of the total figure. Enneads: VI I. 4
If however voice is not characteristically impact, but is simply air, two categories will be involved: voice is significant, and the one category will not be sufficient to account for this significance without associating with a second. Enneads: VI I. 4
This question, however, applies to all the categories: are the two spheres irreconcilable, or can they be co-ordinated with a unity? Enneads: VI I. 12
With regard to Date: If “yesterday,” “to-morrow,” “last year” and similar terms denote parts of time, why should they not be included in the same genus as time? It would seem only reasonable to range under time the past, present and future, which are its species. But time is referred to Quantity; what then is the need for a separate category of Date? If we are told that past and future – including under past such definite dates as yesterday and last year which must clearly be subordinate to past time – and even the present “now” are not merely time but time – when, we reply, in the first place, that the notion of time – when involves time; that, further, if “yesterday” is time-gone-by, it will be a composite, since time and gone-by are distinct notions: we have two categories instead of the single one required. Enneads: VI I. 13
Again, if by “yesterday” we are expected to understand that this or that event has taken Place at a definite time gone by, we have more notions than ever. Besides, if we must introduce fresh categories because one thing acts in another – as in this case something acts in time – we have more again from its acting upon another in another. This point will be made plain by what follows in our discussion of Place. Enneads: VI I. 13
Furthermore, if “in time,” “in place” are to be ranged under a category other than that applying to time and place, why not a separate category for “in a vessel”? Why not distinct categories for “in Matter,” “in a subject,” “a part in a whole,” “a whole in its parts,” “a genus in its species,” “a species in a genus”? We are certainly on the way to a goodly number of categories. Enneads: VI I. 14
Does it follow that whenever alteration proceeds from Quality, it will be activity and Action, the quale remaining impassive? It may be that if the quale remains impassive, the alteration will be in the category of Action; whereas if, while its energy is directed outwards, it also suffers – as in beating – it will cease to belong to that category: or perhaps there is nothing to prevent its being in both categories at one and the same moment. Enneads: VI I. 20
Thus, what is Action in one relation may be Passion in another. One same motion will be Action from the point of view of A, Passion from that of B; for the two are so disposed that they might well be consigned to the category of Relation – at any rate in the cases where the Action entails a corresponding Passion: neither correlative is found in isolation; each involves both Action and Passion, though A acts as mover and B is moved: each then involves two categories. Enneads: VI I. 22
In short, Situation signifies “being in a place”; there are two things involved, the position and the place: why then must two categories be combined into one? Moreover, if sitting signifies an Act, it must be classed among Acts; if a Passion, it goes under the category to which belong Passions complete and incomplete. Enneads: VI I. 24
There are those who lay down four categories and make a fourfold division into Substrates, Qualities, States, and Relative States, and find in these a common Something, and so include everything in one genus. Enneads: VI I. 25
Now if we were obliged to consider Being as a unity, the following questions would be unnecessary: Is there one genus embracing everything, or are there genera which cannot be subsumed under such a unity? Are there first-principles? Are first-principles to be identified with genera, or genera with first-principles? Or is it perhaps rather the case that while not all genera are first-principles, all first-principles are at the same time genera? Or is the converse true? Or again, do both classes overlap, some principles being also genera, and some genera also principles? And do both the sets of categories we have been examining imply that only some principles are genera and some genera principles? or does one of them presuppose that all that belongs to the class of genera belongs also to the class of principles? Since, however, we affirm that Being is not a unity – the reason for this affirmation is stated by Plato and others – these questions become imperative, once we are satisfied as to the number of genera to be posited and the grounds for our choice. Enneads: VI II. 1
What, then, is the meaning of “existence” as applied to fire, earth and the other elements? What is the difference between this existence and existence in the other categories? It is the difference between being simply – that which merely is – and being white. But surely the being qualified by “white” is the same as that having no qualification? It is not the same: the latter is Being in the primary sense, the former is Being only by participation and in a secondary degree. Whiteness added to Being produces a being white; Being added to whiteness produces a white being: thus, whiteness becomes an accident of Being, and Being an accident of whiteness. Enneads: VI III. 6
If however by classing the triangle and the rectangle as qualia we propose to bring figures under Quality, we are not thereby precluded from assigning the same object to more categories than one: in so far as it is a magnitude – a magnitude of such and such a size – it will belong to Quantity; in so far as it presents a particular shape, to Quality. Enneads: VI III. 14
With Quality we have undertaken to group the dependent qualia, in so far as Quality is bound up with them; we shall not however introduce into this category the qualified objects [qua objects], that we may not be dealing with two categories at once; we shall pass over the objects to that which gives them their [specific] name. Enneads: VI III. 19