Against the Professors, Books I-VI of Against the Learned Section 69

εἰ γὰρ περὶ τὸ πιθανὸν ψεῦδος καταγίνεται, πάντως εἴσεται καὶ τὸ ἀπί- θανον. ἐπεὶ οὖν πᾶν ψεῦδος ἤτοι πιθανόν ἐστιν ἀπί- θανον, παντὸς ψεύδους ἐπιστήμη γενήσεται, καὶ διὰ τοῦτο καὶ παντὸς ἀληθοῦς, ὤστ’ αὐτὴν μὴ διαφέρειν τῆς δια- λεκτικῆς ὃ κατὰ πολλοὺς τρόπους ἐστὶν ἄτοπον.

For if it concerns persuasive falsehood, it will necessarily also know the unpersuasive. Since every falsehood is either persuasive or unpersuasive, rhetoric will become knowledge of every falsehood and, for this reason, of every truth as well, so that it will not differ from dialectic, which is absurd in many ways.

En effet, si elle s’occupe du faux persuasif, elle connaîtra nécessairement aussi le faux non-persuasif. Puisque tout faux est persuasif ou non-persuasif, elle deviendra la science de tout faux et, par conséquent, de tout vrai. Elle ne différera donc pas de la dialectique, ce qui est absurde de bien des manières.