[340] Ibid. a. 32-b. 2.
36. Perhaps the definiend is not sufficiently well known to enable you to attack the definition as a whole, but you may find arguments against one or other of its parts; this is sufficient to upset it. If it be obscure and unintelligible, you should help to correct and re-model it until it becomes clear; you will then see what are the really assailable points in it. When you indicate and expose the obscurity, the respondent must either substitute some clearer exposition of his own meaning, or else he must acquiesce in that which you propose as substitute.[341] If the improved definition which you propose is obviously clearer and better, his previous definition is of course put out of court; since there cannot be several definitions of the same subject.[342]
[341] Topic. VI. xiv. p. 151, b. 3-11. ὅσοι τ’ ἀσαφεῖς τῶν ὁρισμῶν, συνδιορθώσαντα καὶ συσχηματίσαντα πρὸς τὸ δηλοῦν τι καὶ ἔχειν ἐπιχείρημα, οὕτως ἐπισκοπεῖν· ἀναγκαῖον γὰρ τῷ ἀποκρινομένῳ ἢ δέχεσθαι τὸ ἐκλαμβανόμενον ὑπὸ τοῦ ἐρωτῶντος, ἢ αὐτὸν διασαφῆσαι τί ποτε τυγχάνει τὸ δηλούμενον ὑπὸ τοῦ λόγου.
[342] Ibid. b. 12-17.
To conclude, one suggestion may be given bearing upon all the arguments that you have to carry on against definitions tendered by respondents:— Reflect on the definiend, and frame a definition of it for yourself, as cleverly as you can at the moment; or call to mind any good definition of it which you may have heard before. This will serve you as a standard with which to compare the definition tendered, so that you will see at once what there is in it either defective or redundant, and where you can find arguments against it.[343]
[343] Ibid. b. 18-23. ἀνάγκη γὰρ, ὥσπερ πρὸς παράδειγμα θεώμενον, τό τ’ ἐλλεῖπον ὧν προσῆκεν ἔχειν τὸν ὁρισμὸν καὶ τὸ προσκείμενον περιέργως καθορᾶν, ὥστε μᾶλλον ἐπιχειρημάτων εὐπορεῖν.
VII.
In the Seventh Book of the Topica Aristotle continues his review of the manner of debating theses which profess to define, but enters also on a collateral question connected with that discussion: viz., By what arguments are we to determine whether two Subjects or Predicates are the same Numero (modo maxime proprio), as distinguished from being the same merely Specie or Genere? To measure the extent of identity between any two subjects, is important towards the attack and defence of a definition.[344]
[344] Ibid. VII. i. p. 151, b. 28: πότερον δὲ ταὐτὸν ἢ ἕτερον κατὰ τὸν κυριώτατον τῶν ῥηθέντων περὶ ταὐτοῦ τρόπων (ἐλέγετο δὲ κυριώτατα ταὐτὸν τὸ τῷ ἀριθμῷ ἕν) &c.
Two subjects (A and B) being affirmed as the same numero, you may test this by examining the Derivatives, the Co-ordinates, and the Opposites, of each. Thus, if courage is identical with justice, the courageous man will be identical with the just man; courageously will be identical with justly. Likewise, the opposite of courage (in all the four modes of Opposition) will be identical with the opposite of justice. Then, again, the generators and destroyers, the generations and destructions, of courage, will be identical with those of justice.[345] If there be any predicate applied to courage in the superlative degree, the same predicate will also be applied to justice in the superlative degree.[346] If there be a third subject C with which A is identical, B also will be identical therewith. The same attributes predicable of A will also be predicable of B; and, if the two be attributes, each will be predicable of the same subjects of which the other is predicable. Both will be comprised in the same Category, and will have the same genus and differentia. Both will increase or diminish under the same circumstances. Each, when added to or subtracted from any third subject, will yield the same result.[347]