Isocrates, Helen 1-3
“There are some people who get puffed up if they manage to talk about something tolerably after they have themselves selected a strange and impossible subject. Men have also grown old claiming that it is impossible to say or disprove a lie or to speak two ways about the same matters. Others claim that courage, wisdom, and justice are the same thing, that we have none of these by nature, and that there is a single knowledge about them all. Others waste their time in conflicts which bring no benefit, which can only create more trouble for those who approach them.
I, if I saw that this superfluity had only just emerged in speeches and that these men were eager for honor in the novelty of what they discover, I would not be a surprised at them. But, now, who is such a late-learner that he does not know Protagoras and the sophists who were active at his time and that they left to us these types of things and speeches even more excessively composed than these? How could anyone overcome Gorgias who dared to say that nothing exists at all or Zeno who tried to demonstrate that the same things are possible and impossible or even Melissos who—although some things are countless in number—tried to provide a proof that everything is one!”
Εἰσί τινες οἳ μέγά φρονοῦσιν, ἢν ὑπόθεσιν ἄτοπον καὶ παράδοξον ποιησάμενοι περὶ ταύτης ἀνεκτῶς εἰπεῖν δυνηθῶσι· καὶ καταγεγηράκασιν οἱ μὲν οὐ φάσκοντες οἷόν τ᾿ εἶναι ψευδῆ λέγειν οὐδ᾿ ἀντιλέγειν οὐδὲ δύω λόγω περὶ τῶν αὐτῶν πραγμάτων ἀντειπεῖν, οἱ δὲ διεξιόντες ὡς ἀνδρία καὶ σοφία καὶ δικαιοσύνη ταὐτόν ἐστι, καὶ φύσει μὲν οὐδὲν αὐτῶν ἔχομεν, μία δ᾿ ἐπιστήμη καθ᾿ ἁπάντων ἐστίν· ἄλλοι δὲ περὶ τὰς ἔριδας διατρίβουσι τὰς οὐδὲν μὲν ὠφελούσας, πράγματα δὲ παρέχειν τοῖς πλησιάζουσι δυναμένας.
Ἐγὼ δ᾿ εἰ μὲν ἑώρων νεωστὶ τὴν περιεργίαν ταύτην ἐν τοῖς λόγοις ἐγγεγενημένην καὶ τούτους ἐπὶ τῇ καινότητι τῶν εὑρημένων φιλοτιμουμένους, οὐκ ἂν ὁμοίως ἐθαύμαζον αὐτῶν· νῦν δὲ τίς ἐστιν οὕτως ὀψιμαθής, ὅστις οὐκ οἶδε Πρωταγόραν καὶ τοὺς κατ᾿ ἐκεῖνον τὸν χρόνον γενομένους σοφιστάς, ὅτι καὶ τοιαῦτα καὶ πολὺ τούτων πραγματωδέστερα συγγράμματα κατέλιπον ἡμῖν; πῶς γὰρ ἄν τις ὑπερβάλοιτο Γοργίαν τὸν τολμήσαντα λέγειν ὡς οὐδὲν τῶν ὄντων ἔστιν, ἢ Ζήνωνα τὸν ταὐτὰ δυνατὰ καὶ πάλιν ἀδύνατα πειρώμενον ἀποφαίνειν, ἢ Μέλισσον ὃς ἀπείρων τὸ πλῆθος πεφυκότων τῶν πραγμάτων ὡς ἑνὸς ὄντος τοῦ παντὸς ἐπεχείρησεν ἀποδείξεις εὑρίσκειν;