[400] Ibid. a. 11-14: ἢ τῷ μὲν μανθάνοντι οὐ θετέον, ἂν μὴ γνωριμώτερον ᾖ, τῷ δὲ γυμναζομένῳ θετέον, ἂν ἀληθὲς μόνον φαίνηται. ὥστε φανερὸν ὅτι οὐχ ὁμοίως ἐρωτῶντί τε κὶ διδάσκοντι ἀξιωτέον τιθέναι.
This section is obscure and difficult. I am not sure that I understand it. It seems doubtful whether the verb τιθέναι is intended to apply to the questioner or to the respondent.
We have now said enough for the purpose of instructing the questioner how to frame and marshal his interrogations. We must turn to the respondent, and point out how he must answer in order to do well and perform his duty to the common work of dialogue. Speaking generally, the task of the questioner is to conduct the dialogue so as to make the respondent enunciate the most improbable and absurd replies which follow necessarily from the thesis that he has undertaken to defend; while the task of the respondent is to make it appear that these absurdities follow from the thesis itself, and not from his manner of defending it. The respondent may err in one of two ways, or indeed in both together: either he may set up an indefensible thesis; or he may fail to defend it in the best manner that it really admits; or he may do both. The second is a worse error than the first, in reference to the general purpose of Dialectic.[401]
[401] Ibid. iv. p. 159, a. 15-24: τοῦ δ’ ἀποκρινομένου τὸ μὴ δι’ αὐτὸν φαίνεσθαι συμβαίνειν τὸ ἀδύνατον ἢ τὸ παράδοξον, ἀλλὰ διὰ τὴν θέσιν· ἑτέρα γὰρ ἴσως ἁμαρτία τὸ θέσθαι πρῶτον ὃ μὴ δεῖ καὶ τὸ θέμενον μὴ φυλάξαι κατὰ τρόπον.
Aristotle distinguishes (as has been already stated) three purposes in the dialogue:— (1) Teaching and Learning; (2) Contention, where both questioner and respondent strive only for victory; (3) Investigating and Testing the consequences of some given doctrine.[402] The first two of these three are dismissed rapidly. In the first, the teaching questioner has no intention of deceiving, and the pupil respondent has only to answer by granting all that appears to him true.[403] In the second, Aristotle tells us only that the questioner must always appear as if he were making some point of his own; while the respondent, on his side, must always appear as if no point were made against him.[404] But in regard to the third head — dialogues of Search, Testing, Exercise — he is more copious in suggestions: he considers these as the proper field of Dialectic, and, as we saw, claims to have been the first who treated them apart from the didactic dialogues on one side, and the contentious on the other.[405]
[402] Ibid. v. p. 159, a. 24-28.
[403] Ibid. a. 29: τῷ μὲν γὰρ μανθάνοντι θετέον ἀεὶ τὰ δοκοῦντα· καὶ γὰρ οὔδ’ ἐπιχειρεῖ ψεῦδος οὐδεὶς διδάσκειν.
[404] Topic. VIII. iv. p. 159, a. 30: τῶν δ’ ἀγνωνιζομένων τὸν μὲν ἐρωτῶντα φαίνεσθαί τι δεῖ ποιεῖν πάντως, τὸν δ’ ἀποκρινόμενον μηδὲν φαίνεσθαι πάσχειν.
[405] Ibid. a. 32-37; xi. p. 161, a. 23-25: δυσκολαίνοντες οὖν ἀγνωνιστικὰς καὶ οὐ διαλεκτικὰς ποιοῦνται τὰς διατριβάς· ἔτι δ’ ἐπεὶ γυμνασίας καὶ πείρας χάριν ἀλλ’ οὐ διδασκαλίας οἱ τοιοῦτοι τῶν λόγων, &c.
The thesis which the respondent undertakes to defend (in a dialogue of Search or Testing) must be either probable, or improbable, or neither one nor the other. The probability or improbability may be either simple and absolute, or special and relative — in the estimation of the respondent himself or of some one or more persons. Now, if the thesis be improbable, the opposite thereof, which you the questioner try to prove, must be probable; if the thesis be probable, the opposite thereof must be improbable; if the thesis be neither, its opposite will also be neither. Suppose, first, that the thesis is improbable absolutely. In that case, its opposite, which you the questioner must fish for premisses to prove, will be probable; the respondent therefore ought not to grant you any demand which is either simply improbable or less probable than the conclusion which you aim at proving; for no such concessions can really serve your purpose, since you are bound to prove your conclusion from premisses more probable than itself.[406] Suppose, next, that the thesis is probable absolutely. In that case, the opposite conclusion, which you have to make out, will be improbable absolutely. Accordingly, whenever you ask concessions that are probable, the respondent ought to grant them; whenever you ask for concessions that are less improbable than your intended conclusion, he ought to grant these also; but, if you ask for any thing more improbable than your intended conclusion, he ought to refuse it.[407] Suppose, thirdly, that the thesis is neither probable nor improbable. Here, too, the respondent ought to grant all concessions that appear to him probable, as well as all that he thinks more probable than the opposite conclusion which you are seeking to arrive at; but no others. This is sufficient for the purpose of Dialectic, and for keeping open the lines of probable argument.[408]