Dio Chrysostom, On Troy Not Being Captured §1:
“I know, roughly speaking, that while it is difficult to teach all people, it is easy to deceive them. They learn only with difficulty (if they learn at all) from a few educated people, but they are almost immediately deceived by a crowd of ignorant fools, and not just by others, but sometimes even by themselves. This is because the truth is bitter and unpleasant to people without knowledge, but falsehood is sweet and pleasant. Thus I suspect that for those with a disorder of the eyes find the light distressing to see, but think the shade painless and pleasant, since it does not permit them to see. But how could falsehood so consistently overpower the truth, if it did not conquer through pleasure?
Though teaching is, as I have said, very difficult, the most difficult thing is to teach someone to change their mind, especially when some people have spent so much time listening to falsehoods, and are not the only ones who have been deceived – their fathers, and grandfathers, and nearly everyone who came before them believed the same falsehoods. For it is not easy to take away this belief, nor can one refute it entirely. I suspect that it is much like when people have raised suppositious children, and it proves to be hard to take them away when the truth is told, but they would not have taken the children in the first place if someone had told them the truth. This has so much power that many people pretend and agree that bad ones are their own, as long as they were early convinced of this, than those who learn of good ones after a long time.”
Οἶδα μὲν ἔγωγε σχεδὸν ὅτι διδάσκειν μὲν ἀνθρώπους ἅπαντας χαλεπόν ἐστιν, ἐξαπατᾶν δὲ ῥᾴδιον. καὶ μανθάνουσι μὲν μόγις, ἐάν τι καὶ μάθωσι, παρ’ ὀλίγων τῶν εἰδότων, ἐξαπατῶνται δὲ τάχιστα ὑπὸ πολλῶν τῶν οὐκ εἰδότων, καὶ οὐ μόνον γε ὑπὸ τῶν ἄλλων, ἀλλὰ καὶ αὐτοὶ ὑφ’ αὑτῶν. τὸ μὲν γὰρ ἀληθὲς πικρόν ἐστι καὶ ἀηδὲς τοῖς ἀνοήτοις, τὸ δὲ ψεῦδος γλυκὺ καὶ προσηνές. ὥσπερ οἶμαι καὶ τοῖς νοσοῦσι τὰ ὄμματα τὸ μὲν φῶς ἀνιαρὸν ὁρᾶν, τὸ δὲ σκότος ἄλυπον καὶ φίλον, οὐκ ἐῶν βλέπειν. ἢ πῶς ἂν ἴσχυε τὰ ψεύδη πολλάκις πλέον τῶν ἀληθῶν, εἰ μὴ δι’ ἡδονὴν ἐνίκα; χαλεποῦ δέ, ὡς ἔφην, ὄντος τοῦ διδάσκειν, τῷ παντὶ χαλεπώτερον τὸ μεταδιδάσκειν, ἄλλως τε ὅταν πολύν τινες χρόνον ὦσι τὰ ψευδῆ ἀκηκοότες καὶ μὴ μόνον αὐτοὶ ἐξηπατημένοι, ἀλλὰ καὶ οἱ πατέρες αὐτῶν καὶ οἱ πάπποι καὶ σχεδὸν πάντες οἱ πρότερον. οὐ γάρ ἐστι ῥᾴδιον τούτων ἀφελέσθαι τὴν δόξαν, οὐδ’ ἂν πάνυ τις ἐξελέγχῃ. καθάπερ οἶμαι τῶν τὰ ὑποβολιμαῖα παιδάρια θρεψάντων χαλεπὸν ὕστερον ἀφελέσθαι τἀληθῆ λέγοντα ἅ γε ἐν ἀρχῇ, εἴ τις αὐτοῖς ἔφρασεν, οὐκ ἄν ποτε ἀνείλοντο. οὕτω δὲ τοῦτο ἰσχυρόν ἐστιν ὥστε πολλοὶ τὰ κακὰ μᾶλλον προσποιοῦνται καὶ ὁμολογοῦσι καθ’ αὑτῶν, ἂν ὦσι πεπεισμένοι πρότερον, ἢ τἀγαθὰ μετὰ χρόνον ἀκούοντες.