Such is Aristotle’s tripartite distribution of Theoretical or Contemplative Science. In introducing us to the study of First Philosophy, he begins by clearing up the meaning of the term Ens. It is a term of many distinct significations; being neither univocal, nor altogether equivocal, but something intermediate between the two, or multivocal. It is not a generic whole, distributed exhaustively among correlative species marked off by an assignable difference:[9] it is an analogical whole, including several genera distinct from each other at the beginning, though all of them branches derivative from one and the same root; all of them connected by some sort of analogy or common relation to that one root, yet not necessarily connected with each other by any direct or special tie.
[9] Metaphys. Γ. ii. p. 1003, a. 33-p. 1004, a. 5: τὸ δ’ ὂν λέγεται μὲν πολλαχῶς, ἀλλὰ πρὸς ἓν καὶ μίαν τινὰ φύσιν, καὶ οὐχ ὁμωνύμως — ὑπάρχει γὰρ εὐθὺς γένη ἔχοντα τὸ ὂν καὶ τὸ ἕν.
Compare K. iii. p. 1060, b. 32. See also above, [ch. iii. p. 60], of the present work.
Of these various significations, he enumerates, as we have already seen, four:— (1) Ens which is merely concomitant with, dependent upon, or related to, another Ens as terminus; (2) Ens in the sense of the True, opposed to Non-Ens in the sense of the False; (3) Ens according to each of the Ten Categories; (4) Ens potentially, as contrasted with Ens actually. But among these four heads, the two last only are matters upon which science is attainable, in the opinion of Aristotle. To these two, accordingly, he confines Ontology or First Philosophy. They are the only two that have an objective, self-standing, independent, nature.
That which falls under the first head (Ens per Accidens) is essentially indeterminate; and its causes, being alike indeterminate, are out of the reach of science. So also is that which falls under the second head — Ens tanquam verum, contrasted with Non-Ens tanquam falsum. This has no independent standing, but results from an internal act of the judging or believing mind, combining two elements, or disjoining two elements, in a way conformable to, or non-conformable to, real fact. The true combination or disjunction is a variety of Ens; the false combination or disjunction is a variety of Non-Ens. This mental act varies both in different individuals, and at different times with the same individual, according to a multitude of causes often unassignable. Accordingly, it does not fall under Ontological Science, nor can we discover any causes or principles determining it.[10] When Aristotle says that the two first heads are out of the reach of science, or not proper subjects of science, he means that their first principia, causes, or deepest foundations, cannot be discovered and assigned; for it is in determining these principia and causes that true scientific cognition consists.[11]
[10] Aristot. Met. E. iv. p. 1027, b. 17; Θ. p. 1051, b. 2; p. 1052, a. 17-30; K. viii. p. 1065, a. 21.
There remains much obscurity about this meaning of Ens (Ens ὡς ἀληθές), even after the Scholia of Alexander (p. 701, a. 10, Sch. Brand.), and the instructive comments of Bonitz, Schwegler, and Brentano (Ueber die Bedeutung des Seienden nach Aristoteles, ch. iii. pp. 21-39).
The foundation of this meaning of Ens lies in the legitimate Antiphasis, and the proper division thereof (τὸ δὲ σύνολον περὶ μερισμὸν ἀντιφάσεως, p. 1027, b. 20). It is a first principle (p. 1005, b. 30) that, if one member of the Antiphasis must be affirmed as true, the other must be denied as false. If we fix upon the right combination to affirm, we say the thing that is: if we fix upon the wrong combination and affirm it, we say the thing that is not (p. 1012, b. 10). “Falsehood and Truth (Aristotle says, E. iv. p. 1027, b. 25) are not in things but in our mental combination; and as regards simple (uncombined) matters and essences, they are not even in our mental combination:â€� οὐ γάρ ἐστι τὸ ψεῦδος καὶ τὸ ἀληθὲς ἐν τοῖς πράγμασιν, οἷον τὸ μὲν ἀγαθὸν ἀληθές, τὸ δὲ κακὸν εὐθὺς ψεῦδος, ἀλλ’ ἐν διανοίᾳ· περὶ δὲ τὰ ἁπλᾶ καὶ τὰ τί ἐστιν οὐδ’ ἐν τῇ διανοίᾳ. Compare Bonitz (ad Ar. Metaph. Z. iv. p. 1030, a.), p. 310, Comm.
In regard to cogitabilia — simple, indivisible, uncompounded — there is no combination or disjunction; therefore, strictly speaking, neither truth nor falsehood (Aristot. De Animâ, III. vi. p. 430, a. 26; also Categor. x. p. 13, b. 10). The intellect either apprehends these simple elements, or it does not apprehend them; there is no διάνοια concerned. Not to apprehend them is ignorance, ἄγνοια, which sometimes loosely passes under the title of ψεῦδος (Schwegler, Comm. Pt. II., p. 32).
[11] Metaphys. E. i. p. 1025, b. 3: αἱ ἀρχαὶ καὶ τὰ αἴτια ζητεῖται τῶν ὄντων, δῆλον δ’ ὅτι ᾗ ὄντα. — ὅλως δὲ πᾶσα διανοητικὴ ἢ μετέχουσά τι διανοίας περὶ αἰτίας καὶ ἀρχάς ἐστιν ἢ ἀκριβεστέρας ἢ ἁπλουστέρας.