[106] Aristotle sometimes speaks of it as χωριστόν, the other Categories being not χωριστά (Metaphys. Z. p. 1028, a. 34). It is not easy, however, always to distinguish whether he means by the term χωριστὰ “sejuncta reâ€�, or “sejuncta notione solâ.â€� See Bonitz ad Metaphysic. (Δ. p. 1017), p. 244.
[107] Categor. p. 3, b. 12: ἄτομον γὰρ καὶ ἓν ἀριθμῷ τὸ δηλούμενόν ἐστιν. Compare Metaphysic. N. p. 1087, b. 33; p. 1088, a. 10.
[108] Hobbes says:— “Now that accident (i.e. attribute) for which we give a certain name to any body, or the accident which denominates its Subject, is commonly called the Essence thereof; as rationality is the essence of a man, whiteness of any white thing, and extension the essence of a body� (Hobbes, Philosophy, ch. viii. s. 23). This topic will be found discussed, most completely and philosophically, in Mr. John Stuart Mill’s System of Logic, Book I. ch. vi. ss. 2-3; ch. vii. s. 5.
[109] Categor. p. 3, b. 13: ἐπὶ δὲ τῶν δευτέρων οὐσιῶν φαίνεται μὲν ὁμοίως τῷ σχήματι τῆς προσηγορίας τόδε τι σημαίνειν, ὅταν εἴπῃ ἄνθρωπον ἢ ζῶον, οὐ μὴν ἀληθές γε, ἀλλὰ μᾶλλον ποιόν τι σημαίνει — ποιὰν γάρ τινα οὐσίαν σημαίνει (b. 20).
Metaphysic. Z. p. 1038, b. 35: φανερὸν ὅτι οὐθὲν τῶν καθόλου ὑπαρχόντων οὐσία ἐστί, καὶ ὅτι οὐθὲν σημαίνει τῶν κοινῇ κατηγορουμένων τόδε τι, ἀλλὰ τοιόνδε. Compare Metaphys. M. p. 1087, a. 1; Sophistic. Elench. p. 178, b. 37; 179, a. 9.
That which is called πρώτη οὐσία in the Categoriæ is called τρίτη οὐσία in Metaphys. Η. p. 1043, a. 18. In Ethic. Nikom. Z. p. 1143, a. 32, seq., the generalissima are called πρῶτα, and particulars are called ἔσχατα. Zell observes in his commentary (p. 224), “τὰ ἔσχατα sunt res singulæ, quæ et ipsæ sunt extremæ, ratione mentis nostræ, ab universis ad singula delabentis.â€� Patricius remarks upon the different sense of the terms Πρώτη Οὐσία in the Categoriæ and in the De Interpretatione (Discuss. Peripatetic. p. 21).
[110] Metaphysic. Δ. p. 1020, b. 13: σχεδὸν δὴ κατὰ δύο τρόπους λέγοιτ’ ἂν τὸ ποιόν, καὶ τούτων ἕνα τὸν κυριώτατον· πρώτη μὲν γὰρ ποιοτὴς ἡ τῆς οὐσίας διαφορά. Compare Physic. v. p. 226, a. 27. See Trendelenburg, Kategorienlehre, pp. 56, 93.
The remarks of the different expositors (contained in Scholia, pp. 52, 53, 54, Brand.), are interesting upon the ambiguous position of Differentia, in regard to Substance and Quality. It comes out to be Neither and Both — οὐδέτερα καὶ ἀμφότερα (Plato, Euthydemus, p. 300 C.). Dexippus and Porphyry called it something intermediate between οὐσία and ποιότης, or between οὐσία and συμβεβηκός.
We see, accordingly, that neither is the line of demarcation between the Category of Substance or Essence and the other Categories so impassable, nor the separability of it from the others so marked as some thinkers contend. Substance is represented by Aristotle as admitting of more and less, and as graduating by successive steps down to the other Categories; moreover, neither in its complete manifestation (as First Substance), nor in its incomplete manifestation (as Second Substance), can it be explained or understood without calling in the other Categories of Quantity, Quality, and Relation. It does not correspond to the definition of Substantia given by Spinoza — “quod in se est et per se concipitur.� It can no more be conceived or described without some of the other Categories, than they can be conceived or described without it. Aristotle defines it by four characteristics, two negative, and two positive. It cannot be predicated of a Subject: it cannot inhere in a Subject: it is, at bottom, the Subject of all Predicates: it is Unum numero and indivisible.[111] Not one of these four determinations can be conceived or understood, unless we have in our minds the idea of other Categories and its relation to them. Substance is known only as the Subject of predicates, that is, relatively to them; as they also are known relatively to it. Without the Category of Relation, we can no more understand what is meant by a Subject than what is meant by a Predicate. The Category of Substance, as laid out by Aristotle, neither exists by itself, nor can be conceived by itself, without that of Relation and the generic notion of Predicate.[112] All three lie together at the bottom of the analytical process, as the last findings and residuum.
[111] Categor. p. 2, a. 14, b. 4; p. 3, b. 12.