Plato, Epinomis 976a

σοφίᾳ δεδομένη. ἣν δὲ καλοῦσι μὲν ἰατρικήν, βοήθεια δέ που καὶ αὕτη σχεδὸν ὅσων ὧραι ψύχει καὶ καύματι ἀκαίρῳ καὶ πᾶσι τοῖς τοιούτοις ληίζονται τὴν τῶν ζῴων φύσιν. εὐδόκιμον δὲ οὐδὲν τούτων εἰς σοφίαν τὴν ἀληθεστάτην· ἄμετρα γὰρ δόξαις φορεῖται τοπαζόμενα. βοηθοὺς δέ που καὶ τοὺς κυβερνήτας ἅμα καὶ τοὺς ναύτας ἐροῦμεν, καὶ τούτων ἄνδρα σοφὸν μηδένα τις ἡμᾶς παραμυθούμενος ἐξ ἁπάντων διαγγελλέτω· οὐ γὰρ ἂν εἰδείη τις πνεύματος ὀργὴν

And that which they call medicine is likewise, of course, an assistance in almost every case towards things of which animal nature is deprived by seasons of untimely cold and heat and all such visitations. But none of these is of high repute for the truest wisdom: for they are borne along by opinion, as inaccurate matter of conjecture. We may, I suppose, speak of pilots and sailors alike as giving assistance: yet you shall not report, to appease us, a single wise man from amongst them all; for a man cannot know