Of the refutations, then, that depend upon ambiguity and amphiboly some contain some question with more than one meaning, while others contain a conclusion bearing a number of senses: e.g. in the proof that ‘speaking of the silent’ is possible, the conclusion has a double meaning, while in the proof that ‘he who knows does not understand what he knows’ one of the questions contains an amphiboly. Also the double-edged saying is true in one context but not in another: it means something that is and something that is not.
Whenever, then, the many senses lie in the conclusion no refutation takes place unless the sophist secures as well the contradiction of the conclusion he means to prove; e.g. in the proof that ‘seeing of the blind’ is possible: for without the contradiction there was no refutation. Whenever, on the other hand, the many senses lie in the questions, there is no necessity to begin by denying the double-edged premiss: for this was not the goal of the argument but only its support. At the start, then, one should reply with regard to an ambiguity, whether of a term or of a phrase, in this manner, that ‘in one sens............