[118] Categor. p. 2, b. 31: τὸν γάρ τινα ἄνθρωπον ἐὰν ἀποδιδῷ τις τί ἐστι, τὸ μὲν εἶδος ἢ τὸ γένος ἀποδιδοὺς οἰκείως ἀποδώσει — τῶν δ’ ἄλλων ὅ τι ἂν ἀποδιδῷ τις, ἀλλοτρίως ἐσται ἀποδεδωκώς, &c.
It is thus that Aristotle has dealt with Ontology, in one of the four distinct aspects thereof, which he distinguishes from each other; that is, in the distribution of Entia according to their logical order, and the reciprocal interdependence, in predication. Ens is a multivocal word, neither strictly univocal nor altogether equivocal. It denotes (as has been stated above) not a generic aggregate, divisible into species, but an analogical aggregate, starting from one common terminus and ramifying into many derivatives, having no other community except that of relationship to the same terminus.[119] The different modes of Ens are distinguished by the degree or variety of such relationship. The Ens Primum, Proprium, Completum, is (in Aristotle’s view) the concrete individual; with a defined essence or essential constituent attributes (τί ἥν εἶναι), and with unessential accessories or accidents also — all embodied and implicated in the One Hoc Aliquid. In the Categoriæ Aristotle analyses this Ens Completum (not metaphysically, into Form and Matter, as we shall find him doing elsewhere, but) logically into Subject and Predicates. In this logical analysis, the Subject which can never be a Predicate stands first; next, come the near kinsmen, Genus and Species (expressed by substantive names, as the First Substance is), which are sometimes Predicates — as applied to Substantia Prima, sometimes Subjects — in regard to the extrinsic accompaniments or accidents;[120] in the third rank, come the more remote kinsmen, Predicates pure and simple. These are the logical factors or constituents into which the Ens Completum may be analysed, and which together make it up as a logical sum-total. But no one of these logical constituents has an absolute or independent locus standi, apart from the others. Each is relative to the others; the Subject to its Predicates, not less than the Predicates to their Subject. It is a mistake to describe the Subject as having a real standing separately and alone, and the Predicates as something afterwards tacked on to it. The Subject per se is nothing but a general potentiality or receptivity for Predicates to come; a relative general conception, in which the two, Predicate and Subject, are jointly implicated as Relatum and Correlatum.[121]
[119] Aristot. Metaphys. Δ. p. 1017, a. 22. καθ’ αὑτὰ δὲ εἶναι λέγεται ὅσαπερ σημαίνει τὰ σχήματα τῆς κατηγορίας· ὀσαχῶς γὰρ λέγεται, τοσαυταχῶς τὸ εἶναι σημαίνει.
[120] Categor. p. 3, a. 1: ὡς δέ γε αἱ πρῶται οὐσίαι πρὸς τὰ ἄλλα πάντα ἔχουσιν, οὕτω τὰ εἴδη καὶ τὰ γένη πρὸς τὰ λοιπὰ πάντα ἔχει· κατὰ τούτων γὰρ πάντα τὰ λοιπὰ κατηγορεῖται.
[121] Bonitz has an instructive note upon Form and Matter, the metaphysical constituents of Prima Substantia, Hoc Aliquid, Sokrates, Kallias (see Aristot. Metaphys. Z. p. 1033, b. 24), which illustrates pertinently the relation between Predicate and Subject, the logical constituents of the same σύνολον. He observes (not. p. 327, ad Aristot. Metaph. Z. p. 1033, b. 19). “Quoniam ex duabus substantiis, quæ quidem actu sint, nunquam una existit substantia, si et formam et materiem utrumque per se esse poneremus, nunquam ex utroque existeret res definita ac sensibilis, τόδε τι. Ponendum potius, si recte assequor Aristotelis sententiam, utrumque (Form and Matter) ita ut alterum exspectet, materia ut formæ definitionem, forma ut materiam definiendam, exspectet, neutra vero per se et absolute sit.â€� What Bonitz says here about Matter and Form is no less true about Subject and Predicate: each is relative to the other — neither of them is absolute or independent of the other. In fact, the explanation given by Aristotle of Materia (Metaph. Z. p. 1028, b. 36) coincides very much with the Prima Essentia of the Categories, if abstracted from the Secunda Essentia. Materia is called there by Aristotle τὸ ὑποκείμενον, καθ’ οὗ τὰ ἄλλα λέγεται. ἐκεῖνο δ’ αὐτὸ μηκέτι κατ’ ἄλλο — λέγω δ’ ὕλην ἣ καθ’ αὑτὴν μήτε τὶ μήτε ποσὸν μήτε ἄλλο μηθὲν λέγεται οἷς ὥρισται τὸ ὄν (p. 1029, a. 20). ἔστι γάρ τι καθ’ οὗ κατηγορεῖται τούτων ἕκαστον, ᾧ τὸ εἶναι ἕτερον καὶ τῶν κατηγοριῶν ἑκάστῃ· τὰ μὲν γὰρ ἄλλα τῆς οὐσίας κατηγορεῖται, αὕτη δὲ τῆς ὕλης.
Aristotle proceeds to say that this Subject — the Subject for all Predicates, but never itself a Predicate — cannot be the genuine οὐσία, which must essentially be χωριστὸν καὶ τὸ τόδε τι (p. 1029, a. 28), and which must have a τί ἦν εἶναι (1029, b. 2). The Subject is in fact not true οὐσία, but is one of the constituent elements thereof, being relative to the Predicates as Correlata: it is the potentiality for Predicates generally, as Materia is the potentiality for Forms.
The logical aspect of Ontology, analysing Ens into a common Subject with its various classes of Predicates, appears to begin with Aristotle. He was, as far as we can see, original, in taking as the point of departure for his theory, the individual man, horse, or other perceivable object; in laying down this Concrete Particular with all its outfit of details, as the type of Ens proper, complete and primary; and in arranging into classes the various secondary modes of Ens, according to their different relations to the primary type and the mode in which they contributed to make up its completeness. He thus stood opposed to the Pythagoreans and Platonists, who took their departure from the Universal, as the type of full and true Entity;[122] while he also dissented from Demokritus, who recognized no true Ens except the underlying, imperceptible, eternal atoms and vacuum. Moreover Aristotle seems to have been the first to draw up a logical analysis of Entity in its widest sense, as distinguished from that metaphysical analysis which we read in his other works; the two not being contradictory, but distinct and tending to different purposes. Both in the one and in the other, his principal controversy seems to have been with the Platonists, who disregarded both individual objects and accidental attributes; dwelling upon Universals, Genera and Species, as the only real Entia capable of being known. With the Sophists, Aristotle contends on a different ground, accusing them of neglecting altogether the essential attributes, and confining themselves to the region of accidents, in which no certainty was to be found;[123] in Plato, he points out the opposite mistake, of confining himself to the essentials, and ascribing undue importance to the process of generic and specific subdivision.[124] His own logical analysis takes account both of the essential and accidental, and puts them in what he thinks their proper relation. The Accidental (συμβεβηκός, concomitant, i.e. of the essence) is per se not knowable at all (he contends), nor is ever the object of study pursued in any science; it is little better than a name, designating the lowest degree of Ens, bordering on Non-Ens.[125] It is a term comprehending all that he includes under his nine last Categories; yet it is not a term connoting either generic communion, or even so much as analogical relation.[126] In the treatise now before us, he does not recognize either that or any other general term as common to all those nine Categories; each of the nine is here treated as a Summum Genus, having its own mode of relationship, and clinging by its own separate thread to the Subject. He acknowledges the Accidents in his classification, not as a class by themselves, but as subordinated to the Essence, and, as so many threads of distinct, variable, and irregular accompaniments, attaching themselves to this constant root, without uniformity or steadiness.[127]
[122] Simplikius ad Categ. p. 2, b. 5; Schol. p. 52, a. 1, Br: Ἀρχύτας ὁ Πυθαγορεῖος οὐ προσίεται τὴν νυνὶ προκειμένην τῶν οὐσίων διαίρεσιν, ἀλλ’ ἄλλην ἀντὶ ταύτης ἐκεῖνος ἐγκρίνει — τῶν μέντοι Πυθαγορείων οὐδεὶς ἂν πρόσοιτο ταύτην τὴν διαίρεσιν τῶν πρώτων καὶ δευτέρων οὐσιῶν, ὅτι τοῖς καθόλου τὸ πρώτως ὑπάρχειν μαρτυροῦσι, τὸ δὲ ἔσχατον ἐν τοῖς μεριστοῖς ἀπολείπουσι, καὶ διότι ἐν τοῖς ἁπλουστάτοις τὴν πρώτην καὶ κυριωτάτην οὐσίαν ἀποτίθενται, ἀλλ’ οὐχ ὡς νῦν λέγεται ἐν τοῖς συνθέτοις καὶ αἰσθητοῖς, καὶ διότι τὰ γένη καὶ τὰ εἴδη ὄντα νομίζουσιν, ἀλλ’ οὐχὶ συγκεφαλαιούμενα ταῖς χωρισταῖς ἐπινοίαις.
[123] Metaphys. E. p. 1026, b. 15: εἰσὶ γὰρ οἱ τῶν σοφιστῶν λόγοι περὶ τὸ συμβεβηκὸς ὡς εἰπεῖν μάλιστα πάντων, &c.; also K. p. 1061, b. 8; Analytic. Poster. i. p. 71, b. 10.
[124] Analytic. Priora, i. p. 46, a. 31.