[378] Ibid. b. 6: ἁπλῶς δ’ εἰπεῖν, ὅτι μάλιστα ποιεῖν ἄδηλον, πότερον τὸ προτεινόμενον ἢ τὸ ἀντικείμενον βούλεται λαβεῖν· ἀδήλου γὰρ ὄντος τοῦ πρὸς τὸν λόγον χρησίμου, μᾶλλον τὸ δοκοῦν αὑτοῖς τιθέασιν.
[379] Ibid. b. 18: δεῖ δὲ καὶ αὐτόν ποτε αὑτῷ ἔνστασιν φέρειν· ἀνυπόπτως γὰρ ἔχουσιν οἱ ἀποκρινόμενοι πρὸς τοὺς δοκοῦντας δικαίως ἐπιχειρεῖν.
[380] Ibid. b. 10, 20: χρήσιμον δὲ καὶ τὸ ἐπιλέγειν ὅτι σύνηθες καὶ λεγόμενον τὸ τοιοῦτον· ὀκνοῦσι γὰρ κινεῖν τὸ εἰωθός, ἔνστασιν μὴ ἔχοντες.
[381] Ibid. b. 23: ἔτι τὸ μὴ σπουδάζειν.
[382] Ibid. b. 30-39: καὶ τὸ ἐπ’ ἐσχάτῳ ἐρωτᾶν ὃ μάλιστα βούλεται λαβεῖν· &c.
[383] Topic. VIII. i. p. 157, a. 1-5: ἔτι τὸ μηκύνειν καὶ παρεμβάλλειν τὰ μηδὲν χρήσιμα πρὸς τὸν λόγον, καθάπερ οἱ ψευδογραφοῦντες· πολλῶν γὰρ ὄντων ἄδηλον ἐν ὁποίῳ τὸ ψεῦδος. διὸ καὶ λανθάνουσιν ἐνίοτε οἱ ἐρωτῶντες ἐν παραβύστῳ προστιθέντες ἃ καθ’ αὑτὰ προτεινόμενα οὐκ ἂν τεθείη.
Such are the multifarious suggestions addressed by Aristotle to the questioner for concealing his method of attack;[384] Concealment being the third of the four general heads relating to the treatment of premisses not immediately necessary for proof of the final refutative conclusion. On the other three general heads — Induction from particulars to an universal, Dignity, Clearness — Aristotle goes into less detail. For Clearness, he recommends that examples should be introduced; especially familiar examples, taken from well-known poets like Homer, not from obscure poets like Chœrilus.[385]
[384] Ibid. a. 6: εἰς μὲν οὖν πρύψιν τοῖς εἰρημένοις χρηστέον, &c.
[385] Ibid. a. 14.
In regard to Induction, Aristotle points out an embarrassment often arising from the want of suitable universal names. When, after having obtained an affirmative answer about several similar particulars, you wish to put a question generalizing the result, you will sometimes find no universal term fitting the position. You are obliged to say: Will it not be so in all such cases? and this lets in a serious difficulty, how to know what other cases are like, and what are not. Here the respondent will often dispute your right to include this or that other particular.[386] You will do well to coin a new universal term fitting the situation.