Yet how can such a confusion be possible? (Sokrates here again replies to himself.) How can knowledge betray a man into such error? If he knows A, and knows B--how can he mistake A for B? Upon this supposition, knowledge produces the effect of ignorance: and we might just as reasonably imagine ignorance to produce the effects of knowledge.[116]--Perhaps (suggests Theætêtus), he may have _non-cognitions_ in his mind, mingled with the cognitions: and in hunting for a cognition, he may catch a non-cognition. Herein may lie false opinion.--That can hardly be (replies Sokrates). If the man catches what is really a non-cognition, he will not suppose it to be such, but to be a cognition. He will believe himself fully to _know_, that in which he is mistaken. But how is it possible that he should confound a non-cognition with a cognition, or _vice versâ_? Does not he know the one from the other? We must then require him to have a separate cognition of his own cognitions or non-cognitions--and so on _ad infinitum_.[117] The hypothesis cannot be admitted. [Footnote 116: Plato, Theæt. p. 199 E.] [Footnote 117: Plato, Theæt. p. 200 B.] We cannot find out (continues Sokrates) what false opinion is: and we have plainly done wrong to search for it, until we have first ascertained what knowledge is.[118] [Footnote 118: Plato, Theæt. p. 200 C.] [Side-note: He brings another argument to prove that Cognition is not the same as true opinion. Rhetors persuade or communicate true opinion; but they do not teach or communicate knowledge.] Moreover, as to the question, Whether knowledge is identical with true opinion, Sokrates produces another argument to prove that it is not so: and that the two are widely different. You can communicate true opinion without communicating knowledge: and the powerful class of rhetors and litigants make it their special business to do so. They persuade, without teaching, a numerous audience.[119] During the hour allotted to them for discourse, they create, in the minds of the assembled dikasts, true opinions respecting complicated incidents of robbery or other unlawfulness, at which none of the dikasts have been personally present. Upon this opinion the dikasts decide, and decide rightly. But they cannot possibly _know_ the facts without having been personally present and looking on. That is essential to knowledge or cognition.[120] Accordingly, they have acquired true and right opinions; yet without acquiring knowledge. Therefore the two are not the same.[121] [Footnote 119: Plato, Theæt. p. 201 A. [Greek: ou(=toi ga/r pou tê=| e(autô=n te/chnê| pei/thousin, ou) dida/skontes, a)lla\ doxa/zein poiou=ntes a(\ a)\n bou/lôntai.]] [Footnote 120: Plato, Theæt. p. 201 B-C. [Greek: Ou)kou=n o(/tan dikai/ôs peisthô=si dikastai\ peri\ _ô(=n i)do/nti mo/non e)/stin ei)de/nai, a)/llôs de\ mê/_, tau=ta to/te _e)x a)koê=s kri/nontes_, a)lêthê= do/xan labo/ntes, a)/neu e)pistê/mês e)/krinan, o)rtha\ peisthe/ntes, ei)/per eu)= e)di/kasan?]]