[419] Ibid. b. 17-22: ἄδοξον δ’ ὑπόθεσιν εὐλαβητέον ὑπέχειν· εἴη δ’ ἂν ἄδοξος διχῶς· &c.
The respondent must farther be able, if you bring against him a false syllogistic reasoning, to distinguish upon which among your premisses the false conclusion really turns, and to refute that one. Your reasoning may have more than one false premiss; but he must not content himself with refuting any one or any other: he must single out that one which is the chief determining cause of the falsehood. Thus, if your syllogism be:— Every man in a sitting position is writing, Sokrates is a man in a sitting position; therefore, Sokrates is writing, — it will not suffice that the respondent should refute your minor premiss, though this may be false;[420] because such a refutation will not apply to the number of other cases in which men are sitting but not writing; and therefore it will not expose the full bearing of the falsehood. Your major premiss is that upon which the full bearing of the falsehood depends; and the respondent must show that he is aware of this by refuting your major.[421]
[420] Topic. VIII. x. p. 160, b. 23-26. οὐ γὰρ ὁ ὁτιοῦν ἀνελὼν λέλυκεν, οὔδ’ εἰ ψεῦδός ἐστι τὸ ἀναιρούμενον· ἔχοι γὰρ ἂν πλείω ψευδῆ ὁ λόγος.
[421] Ibid. b. 30-39. οἶδε δὲ τὴν λύσιν ὁ εἰδὼς ὅτι παρὰ τοῦτο ὁ λόγος — οὐ γὰρ ἀπόχρη τὸ ἐνστῆναι, οὔδ’ ἂν ψεῦδος ᾖ τὸ ἀναιρούμενον, ἀλλὰ καὶ διότι ψεῦδος ἀποδεικτέον· οὕτω γὰρ ἂν εἴη φανερὸν πότερον προορῶν τι ἢ οὒ ποιεῖται τὴν ἔνστασιν.
This last-mentioned proceeding — refutation of that premiss upon which your false conclusion in its full bearing really turns — is the only regular, valid, and complete objection whereby the respondent can stop out your syllogistic approaches. There are indeed three other modes of objection to which he may resort; but these are all either inconclusive or unfair. He may turn his objection against you personally; and, without refuting any of your premisses, he may thus perplex and confuse you, so that you are disqualified from pursuing the thread of your questions. Or he may turn his objections against portions of your questions; not refuting any one of your premisses, but showing that, as they stand, they are insufficient to warrant the conclusion which you seek to establish; when, if you are master of your subject, and retain your calmness, you will at once supply the deficiency by putting additional questions, so that his objection thus vanishes. Or, lastly, he may multiply irrelevant objections against time, for the purpose of prolonging the discussion and tiring you out.[422] Of these four modes of objection open to the respondent the first is the only one truly valid and conclusive; the three others are obstructions either surmountable or unfair, and the last is the most discreditable of all.[423]
[422] Ibid. p. 161, a. 1-12: ἔστι δὲ λόγον κωλῦσαι συμπεράνασθαι τετραχῶς. ἢ γὰρ ἀνελόντα παρ’ ὃ γίνεται τὸ ψεῦδος. ἢ πρὸς τὸν ἐρωτῶντα ἔνστασιν εἰπόντα· — τρίτον δὲ πρὸς τὰ ἠρωτημένα· — τετάρτη δὲ καὶ χειρίστη τῶν ἐνστάσεων ἡ πρὸς τὸν χρόνον.
[423] Ibid. a. 13-15: αἱ μὲν οὖν ἐνστάσεις, καθάπερ εἴπαμεν, τετραχῶς γίνονται· λύσις δ’ ἐστὶ τῶν εἰρημένων ἡ πρώτη μόνον, αἱ δὲ λοιπαὶ κωλύσεις τινὲς καὶ ἐμποδισμοὶ τῶν συμπερασμάτων.
To blame the argumentative procedure and to blame the questioner are two distinct things. Perhaps your manner of conducting the interrogation, preparatory to your final syllogism, may be open to censure; yet nevertheless you the questioner may deserve no censure; for it may be the respondent’s fault, not yours. He may refuse to grant the very premisses which are essential to the good conduct of your case; he may resort to perverse evasions and contradictions for the mere purpose of thwarting you; so that you are forced to adapt yourself to his unworthy manœuvres rather than to aim at the thesis itself. Dialectic cannot be well conducted unless both the partners do their duty to the common purpose; the bad conduct of your respondent puts you out, and the dialectic presently degenerates on both sides into angry contention.[424] Apart from this, too, it must be remembered that the express purpose of Dialectic is not to teach, but to search and test consequences and to exercise the intellect of both parties. Accordingly you are not always restricted to true syllogistic premisses and conclusions. You are allowed to resort occasionally to false premisses and false conclusions; for, if what the respondent advances be true, you have no means of refuting it except by falsehood; and, if what he advances be false, the best way of refuting it may be through some other falsehood.[425] You render service to him by doing so; for, since his beliefs are contrary to truth, if the dialogue is confined to his beliefs, the result may perhaps contribute to persuade him, but it will not instruct or profit him.[426] It is your business to bring him round and emancipate him from these erroneous beliefs; but you must accomplish this in a manner truly dialectical, and not contentious; whether you proceed by true or by false conclusions.[427] If you on your side, indeed, put questions in a contentious spirit, it is you that are to blame. But often the respondent is most to blame, when he refuses to grant what he thinks probable, and when he does not apprehend what you really intend to ask.[428] He is sometimes also to blame for granting what he ought to refuse; such as Petitio Principii or Affirmation of Contraries. It is often difficult to distinguish what questions involve Petitio Principii or Affirmation of Contraries: they are asked and granted without either party being aware, and the like mistake is committed by men in private talk, not merely in formal dialogue. When this happens, the argument will inevitably be a bad one; but the fault is with the respondent who, having before refused what he ought to have granted, now grants what he ought to refuse.[429]
[424] Topic. VIII. xi. p. 161, a. 16-24. δυσκολαίνοντες οὖν ἀγωνιστικὰς καὶ οὐ διαλεκτικὰς ποιοῦνται τὰς διατριβάς. a. 37: φαῦλος κοινωνὸς ὁ ἐμποδίζων τὸ κοινὸν ἔργον.
[425] Ibid. a. 24-31: ἔτι δ’ ἐπεὶ γυμνασίας καὶ πείρας χάριν ἀλλ’ οὐ διδασκαλίας οἱ τοιοῦτοι τῶν λόγων, δῆλον ὡς οὐ μόνον τἀληθῆ συλλογιστέον ἀλλὰ καὶ ψεῦδος, οὐδὲ δι’ ἀληθῶν ἀεὶ ἀλλ’ ἐνίοτε καὶ ψευδῶν. πολλάκις γὰρ ἀληθοῦς τεθέντος ἀναιρεῖν ἀνάγκη τὸν διαλεγόμενον, ὥστε προτατέον τὰ ψευδῆ. ἐνίοτε δὲ καὶ ψεύδους τεθέντος ἀναιρετέον διὰ ψευδῶν.