Hence we draw another argument for not admitting the Platonic doctrine of Ideas, affirmed by the dialecticians (οἱ ἐν τοῖς λόγοις — p. 1050, b. 35). If there existed such Ideas, they would be only δυνάμεις in respect to the ἐνέργεια existing in their particular embodiments. Thus an individual cognizing man would be much more cognizant than αὐτοεπιστήμη; a particular substance in motion would be much more in motion than κίνησις or αὐτοκίνησις itself. For αὐτοεπιστήμη or αὐτοκίνησις are only δυνάμεις to the ἐπιστῆμόν τι or the κινούμενόν τι, which belong to ἐνέργεια (b. 36). (We may remark that in the Platonic Parmenides, p. 134, C., an argument the very opposite to this is urged. It is there contended that Cognitio per se (the Idea) must be far more complete and accurate than any cognition which we possess.)
It is thus plain that ἐνέργεια is prius to δύναμις, and to every principle of change (p. 1051, a. 2). It is also better and more honourable than δύναμις even in the direction of good. We have already observed that δύναμις always includes both of two contraries, in the way of alternative: one of these must be the good, the other the bad. Now the actuality of good is better than the potentiality of good; the actuality of health is better than the potentiality of health, which latter must also include the potentiality of sickness, while the actuality of health excludes the actuality of sickness. On the other hand, the actuality of evil is worse than the potentiality of evil; for the potentiality is neither of the two contraries or both of them at once (a. 17). Hence we see that evil is nothing apart from particular things; since it is posterior in its nature even to Potentiality: there is therefore neither evil, nor error, nor destruction, in any of the principia or eternal Essences (a. 19). (The note of Bonitz here is just:— “Quem in hac argumentatione significavi errorem — judicium morale de bono et malo immisceri falso iis rebus, a quibus illud est alienum — ei non dissimilem Arist. in proximâ argumentatione, si recte ejus sententiam intelligo, videtur admisisse, quum quidem malum non esse παρὰ τὰ πράγματα, seorsim ac per se existens, demonstrare conatur.â€� Aristotle here as elsewhere confounds the idea of Good, Perfection, Completeness, &c., with that of essential Priority. But what he says here — οὐκ ἔστι τὸ κακὸν παρὰ τὰ πράγματα — can hardly be reconciled with what he says in the Physica (pp. 189, 191, 192) about στέρησις, which he includes among the three ἀρχαί, and which he declares to be κακοποιός — p. 192, a. 15.)
Lastly, we discover geometrical truths by drawing visible diagrams, and thus translating the Potentialities into Actuality. If these diagrams were ready drawn for us by nature, there would be no difficulty in seeing these truths; but, as the case stands, the truths only inhere in the figures potentially (p. 1051, a. 23: εἰ δ’ ἦν διῃρηνένα, φανερὰ ἂν ἦν· νῦν δ’ ἐνυπάρχει δυνάμει). If the triangle had a line ready drawn parallel to its side, we should have seen at once that its three angles were equal to two right angles. Potential truths are thus discovered by being translated into Actuality. The reason of this is, that the Actuality is itself an act of cogitation, so that the Potentiality springs from Actuality (αἴτιον δ’ ὅτι νόησις ἡ ἐνέργεια· ὥστ’ ἐξ ἐνεργείας ἡ δύναμις — a. 30. It is not therefore true — what the Platonists say — that the mathematical bodies and their properties are οὐσίαι καὶ ἐνεργεῖαι: they are only δυνάμεις, and they are brought into being by our cogitation or abstraction). It is true that each individual diagram drawn is posterior to the power of drawing it (a. 32).
Having gone through the discussion of Ens according to the first of the ten Categories, and of Ens Potential and Actual, we have now to say something about Ens as True or False in the strictest sense of the words (τὸ δὲ κυριώτατα ὂν ἀληθὲς ἢ ψεῦδος — p. 1051, b. 1). These words mean, in reference to things, either that they are conjoined or that they are disjoined. To speak truth is to affirm that things which are disjoined or conjoined in fact, are disjoined or conjoined; to speak falsely, the reverse. The appeal is to the fact: it is not because we truly call you white, that you are white; it is because you really are white, that we who call you white speak truth (b. 9). If there are some things which are always conjoined, others always disjoined, others again sometimes conjoined sometimes disjoined, propositions in reference to the first two classes affirming conjunction or disjunction, will be always true or always false, while in reference to the third class propositions may be either true or false, according to the case (b. 10).
But what shall we say in regard to things Uncompounded? In respect to them, what is truth or falsehood — to be or not to be? (τὰ ἀσύνθετα — p. 1051, b. 18). If we affirm white of the wood, or incommensurability of the diagonal, such conjunction of predicate and subject may be true or false; but how, if there be no predicate distinct from the subject? Where there is no distinction between predicate and subject, where the subject stands alone, — in these cases, there is no truth or falsehood in the sense explained above: no other truth except that the mind apprehends and names the subject, or fails to do so. You either know the subject, or you do not know it: there is no alternative but that of knowledge or ignorance; to be deceived is impossible about the question Quid est (τὸ μὲν θιγεῖν καὶ φάναι ἀληθές, οὐ γὰρ ταὐτὸ κατάφασις καὶ φάσις, τὸ δ’ ἀγνοεῖν μὴ θιγγάνειν· ἀπατηθῆναι γὰρ περὶ τὸ τί ἐστιν οὐκ ἔστιν ἀλλ’ ἢ κατὰ συμβεβηκός — b. 25. The last words are thus explained by Bonitz: “nisi forte per abusum quendam vocabuli ipsam ignorantiam dixeris erroremâ€� — p. 411.). All these uncompounded subjects exist actually, not potentially: if the latter had been true, they would have been generated and destroyed; but Ens Ipsum (τὸ ὂν αὐτό — b. 29) is neither generated nor destroyed; for, if it had been, it must have been generated out of something. Respecting all those things which exist in Essence and Actuality, you cannot be deceived: you may apprehend them in cogitation, or fail to apprehend them. The essential question respecting them is, whether they exist in such or such manner or not; as it is respecting the One and the Uncompounded — whether, being an existent, it exists thus and thus or not (b. 35). Truth consists in apprehending or cogitating them (p. 1052, a. 1): the contrary thereof is non-apprehension of them or ignorance (ἄγνοια), yet not analogous to blindness; for that would be equivalent to having no apprehensive intelligence (ὡς ἂν εἰ τὸ νοητικὸν ὅλως μὴ ἔχοι τις — a. 3; one is not absolutely without νοητικόν, but one’s νόησις does not suffice for apprehending these particular objects).
Respecting objects immoveable and unchangeable, and apprehended as such, it is plain that there can be no mistake as to the When (κατὰ τό ποτέ â€” p. 1052, a. 5; i.e., a proposition which is true of them at one time cannot be false at another time). No man will suppose a triangle to have its three angles equal to two right angles at one time, but not at another. Even in these unchangeables, indeed, a man may mistake as to the What: he may suppose that there is no even number which is a prime number, or he may suppose that there are some even numbers which are prime, others which are not so; but, respecting any particular number, he will never suppose it to be sometimes prime, sometimes not prime (a. 10).
(In respect to the meaning of τὰ ἀσύνθετα — p. 1051, b. 17 — Bonitz and Schwegler differ. Bonitz says, Comm. p. 409: “Compositæ quas dicit non sunt intelligendæ eæ quæ ex pluribus elementis coaluerunt, sed eæ potius, in quibus cum substantia conjungitur accidens aliquod, veluti homo albus, homo sedens, diagonalis irrationalis, et similia.â€� Schwegler says, p. 187: “Unter den μὴ συνθεταὶ οὐσίαι versteht Arist. näher diejenigen Substanzen, die nicht ein σύνθετον oder σύνολον sondern ἄνευ ὕλης (οὐ δυνάμει) und schlechthin ἐνεργείᾳ, also reine Formen sind, und als solche kein Werden und Vergehen haben.â€� Of these two different explanations, I think that the explanation given by Bonitz is the more correct, or at least the more probable.)
Book Λ.
We have to speculate respecting Essence; for that which we are in search of is the principles and causes of Essences (p. 1069, a. 18). If we look upon the universe as one whole, Essence is the first part thereof: if we look upon it as a series of distinct units (εἰ τῷ ἐφεξῆς, a. 20), even in that view οὐσία stands first, ποιόν next, ποσόν third; indeed these last are not Entia at all, strictly speaking (a. 21) — I mean, for example, qualities and movements, and negative attributes such as not-white and not-straight; though we do talk of these last too as Entia, when we say Est non-album. Moreover Essence alone, and none of the other Categories, is separable. The old philosophers (οἱ ἀρχαῖοι) are in the main concurrent with us on this point, that Essence is prius to all others; for they investigated the principles, the elements, and the causes of Essence. The philosophers of the present day (Plato, &c.) declare Universals, rather than Particulars, to be Essences; for the genera are universal, which these philosophers, from devoting themselves to dialectical discussions, affirm to be more properly considered as Principles and Essences (a. 28); but the old philosophers considered particular things to be Essences, as fire and earth, for example, not the common body or Body in general (οὐ τὸ κοινὸν σῶμα — a. 30).