Epictetus

“ Is it not, then, necessary that a man should also acquire this power, if he is to acquit himself intelligently in argument, and is himself not only to prove each point when he tries to prove it, but also to follow the argument of those who are conducting a proof, and is not to be misled by men who quibble as though they were proving something? ”

“ Three modes of sophistical reasoning are here differentiated. "Equivocal premisses" (μεταπίπτοντες λόγοι) are those that contain ambiguities in terms which are intended to mean one thing at one step in the argument, another at another. "Hypothetical premisses" involve assumptions, or conditions. The last class proceeds by drawing unexpected conclusions from the answers to questions. ”

“ Of the use of equivocal premisses, hypothetical arguments and the like
Most men are unaware that the handling of arguments which involve equivocal and hypothetical premisses, and, further, of those which derive syllogisms by the process of interrogation, and, in general, the handling of all such arguments, [1] has a bearing upon the duties of life. For our aim in every matter of inquiry is to learn how the good and excellent man may find the appropriate course through it and the appropriate way of conducting himself in it. ”