There are four principal varieties of meaning in this Essentia, κυρίως or sensu dignissimo: (1) τὸ τί ἦν εἶναι, (2) τὸ καθόλου, (3) τὸ γένος, (4) τὸ ὑποκείμενον.
We shall first speak about the fourth — Substratum — which is the subject of all predicates, but never itself the predicate of any subject. That which appears most of all to be Essentia is, τὸ ὑποκείμενον πρῶτον. This name applies, in one point of view, to Matter; in another, to Form; in a third, to the total result of the two implicated together (p. 1029, a. 1): e.g., the brass, the figure, and the complete statue of figured brass. If, therefore, the Form be prius, and more Ens, as compared with the Matter, it will be also prius and more Ens as compared with the complete result. We get thus far in the adumbration of Essentia — that it is the subject of all predicates, but never itself a predicate.
But this is not sufficient to define it: there still remains obscurity. It would seem that Matter is Essentia; and that, if it be not so, nothing else is discernible to be so; for, if every thing else be subtracted, nothing (save Matter) remains. All things else are either affections, or agencies, or powers, of bodies; and, while length, breadth, depth, &c., are quantities belonging to Essence, Quantity is not Essence, but something belonging to Essence as First Subject. Take away length, breadth, depth, and there will remain only that something which these three circumscribe; in other words, Matter — that which, in itself and in its own nature, is neither Quantity, nor Quality, but of which, Quantity, Quality, and the other Categories, are predicated. All these Categories are predicated of Essence, and Essence of Matter; so that Matter is the last remaining per se (p. 1029, a. 12-24). Take away Matter, and there remain neither affirmative nor negative predicates; for these negative predicates are just as much concomitants or accidents as the others (a. 25).
Upon this reasoning, it seems that Matter is the true Essence. Yet, on the other hand, this will be seen to be impossible. For the principal characteristic of Essence is to be separable and Hoc Aliquid. So that either Form, or the Compound of Form and Matter together, must be the true Essence. But this last, the Compound, may be dismissed as evidently unsuitable for the enquiry, not less than Matter separately; for it is manifestly posterior to either of the two components (p. 1029, a. 30). We must therefore investigate the Form, though it is full of difficulty (a. 33).
We shall begin the investigation from some of the Percipienda, which are acknowledged as Essence; for it is useful to go across from this starting-point to what is more cognizable (πρὸ ἔργου γὰρ τὸ μεταβαίνειν εἰς τὸ γνωριμώτερον — p. 1029, b. 3. These words ought properly to come immediately after ζητητέον πρῶτον — p. 1028, a. 35, and the intervening words now standing in the text, ἐπεὶ δ’ ἐν ἀρχῇ — περὶ αὐτοῦ, ought to be transferred to a more proper place some lines lower down, immediately before the words, καὶ πρῶτον εἴπωμεν — p. 1029, b. 12. Bonitz has made this very just correction in his Observatt. pp. 129-130, referred to in his Notes on the Metaphysica.). Every man learns in this way — by proceeding from what is less cognizable by nature to what is more cognizable by nature. And the business (ἔργον) of learning consists in making what is most cognizable to nature, most cognizable to ourselves also; just as, in practical matters, proceeding from what is good for each, to make what is good by nature good also for each man’s self. For it will often happen that things first and most cognizable to each man’s self, are only faintly cognizable, and have little or nothing of Ens (b. 9). Yet still, we must try to become cognizant of things fully knowable, by beginning with things poorly knowable, but knowable to us (b. 12).
Taking up these Percipienda, for the purpose of searching for Essentia in them, we shall first advert to τί ἦν εἶναι, which we discriminated as one of the characteristics of Essentia, saying something about the rational explanation or definition of it (p. 1029, a. 12). The τ.η.ε. of each subject is what is affirmed of it per se (ἔστι τὸ τ.η.ε. ἑκάστῳ ὃ λέγεται καθ’ αὑτό — a. 13). Your essence is not to be musical; you are not musical by yourself: your essence is, what you are by yourself. Nor does it even include all that you are by yourself. Surface is not included in the essence of white; for the essence of surface is not the same thing as the essence of white. Moreover white surface, the compound of both, is not the essence of white; because white itself is included in the definition of white — which cannot be tolerated. The definition, which explains τ.η.ε., must not include the very word of which you intend to declare the τ.η.ε. If you intend to declare the τ.η.ε. of white surface by the words smooth surface, this does not declare it all: you only declare that white is identical in meaning with smooth (b. 22).
Now, since there are compounds in every one of the Categories, we must enquire whether there is a τ.η.ε. belonging to each of these. Is there, for example, a τ.η.ε. for white man? Let the meaning of these two words be included in the single word garment. Is there a τ.η.ε. for garment? What is it to be a garment? You cannot answer; for neither is this an enunciation per se (p. 1029, b. 29). Are we to say, indeed, that there are two distinct sorts of enunciation per se: one including an addition (ἐκ προσθέσεως), the other, not? You may define by intimating something to which the matter defined belongs; e.g., in defining white you may give the definition of white man. Or you may define by intimating something which is not essential but accessory to the matter defined; e.g., garment signifying white man, you may define garment as white. Whereas the truth is, that, though a white man is white, yet to be white is accessory and not essential to him (p. 1030, a. 1).
But can we in any way affirm that there is any τ.η.ε. to garment (taken in the above sense)? Or ought we to say that there is none (p. 1030, a. 2; Bonitz. Obss. p. 120)? For the τ.η.ε. is of the nature of τόδε τι (ὅπερ γὰρ τόδε τι ἔστι τὸ τ.η.ε. — a. 3), or Hoc Aliquid, i.e., a particular concrete; but, when one thing is affirmed of another, as when we say white man, this is not of the nature of τόδε τι, if τόδε τι belongs to Essences alone (a. 5). Thus it appears that τόδε τι belongs to all those matters of which the rational explanation can be given by Definition. For to give the equivalent of a name in many other words is not always to give a definition: if this were so, a paraphrase of any length, even the Iliad, might be called a definition. There can be no definition except of a primary something; which is affirmed, without being affirmed as something about another (a. 10). There will be no τ.η.ε., therefore, except for species of a genus; for in these alone what is affirmed is not an affection or an accessory or by way of participation. Respecting every thing besides, there will be no τ.η.ε. or definition, but there may be a rational explanation (λόγος) of what the name signifies, or a more precise explanation substituted in place of a simpler (a. 16).
Yet have we not gone too far in restricting the applicability of τ.η.ε. and Definition? and ought we not rather to say, that both the one and the other are used in many different senses (p. 1030, a. 18)? For the Quid est (τὸ τί ἐστιν) signifies in one way Essence and Hoc Aliquid, and in different ways all the other Categories each respectively. To all of them Est belongs, though not in like manner, but primarily to one and consequentially to the rest; so also Quid est belongs simply and directly to Essence, but in a certain way to the others (a. 21). Respecting Quale, Quantum, and the rest, we may enquire Quid Est? so that Quale also comes under the Quid est, though not absolutely or directly (οὐχ ἁπλῶς, a. 25), but analogously to Non-Ens; for some assert in words that Est belongs to Non-Ens also though not absolutely, viz., Non Ens est Non-Ens — (a. 26).
Now we ought to be careful how we express ourselves about any particular matter, but we ought not to be less careful to determine how the matter itself really stands (p. 1030, a. 27: δεῖ μὲν οὖν σκοπεῖν καὶ τὸ πῶς δεῖ λέγειν περὶ ἕκαστον, οὐ μὴν μᾶλλόν γε ἢ τὸ πῶς ἔχει. This contrast of πῶς δεῖ λέγειν with πῶς ἔχει appears to refer to what had been said two lines before: λογικῶς φασί τινες εἶναι τὸ μὴ ὄν — verbal propositions distinguished from real.). The phraseology used just before is clear, and we must therefore recognize that τ.η.ε., as well as τί ἐστι, belongs absolutely and primarily to Essentia, but in a secondary way to the other Categories; that is not absolutely, but ποιῷ τ.η.ε., πόσῳ τ.η.ε., &c. (a. 31). For we must either declare the Categories to be simply æquivoca, or we must recognize this addition and subtraction of the separate title of each, like the non-cognizable cognizable (ὥσπερ καὶ τὸ μὴ ἐπιστητὸν ἐπιστητόν — a. 33. I do not understand these words, nor does the Scholiast or Bonitz explain them satisfactorily.). But the truth is, that they are neither æquivoca nor univoca, but in an intermediate grade of relation — not καθ’ ἕν, but πρὸς ἕν (b. 3.). People may express this in what phrases they like; but the truth is, that there is both τ.η.ε. and Definition, directly and primarily, of Essence; and of the other Categories also, but not directly and primarily. Of white man, you may give a rational explanation and a definition; but it will apply in a different manner to white and to the essence of man (b. 12).