The propositions which we have hitherto studied have been indefinite; that is, they might be universal or not. But if we attach to them the sign of universality, and construe them as universals, all that we have said about them would still continue to be true, except that the propositions which are diametrically (or diagonally) opposed would not be both true in so many instances. Thus, let us take the first quaternion of propositions, in which est is attached to homo, and let us construe these propositions as universal. They will stand thus —
(A) Omnis est homo justus … … … … (B) Non omnis est homo justus. (D) Non omnis est homo non justus … … … … (C) Omnis est homo non justus.
| (A) Omnis est homo justus | … … … … | (B) Non omnis est homo justus. |
| (D) Non omnis est homo non justus | … … … … | (C) Omnis est homo non justus. |
In these propositions, as in the others before noticed, the same relation prevails between C and B, and between A and D; if C be true, B also is true, but not vice versâ; if A be true, D also will be true, but not vice versâ. But the propositions diagonally opposed will not be so often alike true:[26] thus, if A be true (Omnis est homo justus), C cannot be true (Omnis est homo non justus); whereas in the former quaternion of propositions (indefinite, and therefore capable of being construed as not universal) A and C might both be alike true.[27]
[26] Aristot. De Interpret. p. 19, b. 35. πλὴν οὐχ ὁμοίως τὰς κατὰ διάμετρον ἐνδέχεται συναληθεύειν· ἐνδέχεται δὲ ποτέ. The “diameterâ€� or “diagonalâ€� is to be understood with reference to the scheme or square mentioned p. 119, note, the related propositions standing at the angles, as above.
[27] The Scholion of Ammonius, p. 123, a. 17, Br., explains this very obscure passage: ἀλλ’ ἐπὶ μὲν τῶν ἀπροσδιορίστων (indefinite propositions, such as may be construed either as universal or as particular), κατὰ τὴν ἐνδεχομένην ὕλην τάς τε καταφάσεις (of the propositions diagonally opposite), συναληθεύειν ἀλλήλαις συμβαίνει καὶ τὰς ἀποφάσεις, ἅτε ταῖς μερικαῖς ἰσοδυναμούσας. ἐπὶ δὲ τῶν προσδιωρισμένων (those propositions where the mark of universality is tacked to the Subject), περὶ ὧν νυνὶ αὐτῷ ὁ λόγος, τῆς καθόλου καταφάσεως καὶ τῆς ἐπὶ μέρους ἀποφάσεως, τὰς μὲν καταφάσεις ἀδύνατον συναληθεῦσαι καθ’ οἱανδήποτε ὕλην, τὰς μέντοι ἀποφάσεις συμβαίνει συναληθεύειν κατὰ μόνην τὴν ἐνδεχομένην· &c.
It is thus that Aristotle explains the distinctions of meaning in propositions, arising out of the altered collocation of the negative particle; the distinction between (1) Non est justus, (2) Est non justus, (3) Est injustus. The first of the three is the only true negative, corresponding to the affirmative Est Justus. The second is not a negative at all, but an affirmative (ἐκ μεταθέσεως, or by transposition, as Theophrastus afterwards called it). The third is an affirmative, but privative. Both the second and the third stand related in the same manner to the first; that is, the truth of the first is a necessary consequence either of the second or of the third, but neither of these can be certainly inferred from the first. This is explained still more clearly in the Prior Analytics; to which Aristotle here makes express reference.[28]
[28] Aristot. De Interpr. p. 19, b. 31. ταῦτα μὲν οὖν, ὥσπερ ἐν τοῖς Ἀναλυτικοῖς λέγεται, οὕτω τέτακται.
Waitz in his note suggests that instead of τέτακται we ought to read τετάχθω. But if we suppose that the formal table once existed in the text, in an order of arrangement agreeing with the Analytica, this conjectural change would be unnecessary.
Waitz has made some changes in the text of this chapter, which appear to me partly for the better, partly not for the better. Both Bekker and Bussemaker (Firmin Didot) retain the old text; but this old text was a puzzle to the ancient commentators, even anterior to Alexander of Aphrodisias. I will here give first the text of Bekker, next the changes made by Waitz: my own opinion does not wholly coincide with either. I shall cite the text from p. 19, b. 19, leaving out the portion between lines 30 and 36, which does not bear upon the matter here discussed, while it obscures the legitimate sequence of Aristotle’s reasoning.