Laudator Temporis Acti

Marcus Aurelius, Meditations 6.21 (tr. Robin Waterfield):

If someone can prove me wrong and show me that something I thought or did was mistaken, I'll gladly change, because my goal is the truth and the truth has never harmed anyone. The man who's harmed is the one who persists in his own self-deception and ignorance.

εἴ τίς με ἐλέγξαι καὶ παραστῆσαί μοι, ὅτι οὐκ ὀρθῶς ὑπολαμβάνω ἢ πράσσω, δύναται, χαίρων μεταθήσομαι· ζητῶ γὰρ τὴν ἀλήθειαν, ὑφ᾿ ἧς οὐδεὶς πώποτε ἐβλάβη. βλάπτεται δὲ ὁ ἐπιμένων ἐπὶ τῆς ἑαυτοῦ ἀπάτης καὶ ἀγνοίας.

Christopher Gill ad loc.:

This chapter has strong Socratic echoes. These include the idea the need for continuing search ('I am looking for', zēteō) for knowledge of truth on which to base one's life. The echoes also include the idea that since people go wrong by mistake, it is advantageous 'if someone can prove me wrong (elenchein, a favourite Socratic term)', and that people are harmed not by truth but by persisting in ignorance. See e.g. Apol. 21b–22e (on Socrates' search for truth); 30b–30d (on what constitutes 'harm') and 38a (for the idea that 'the unexamined life is not worth living'); also Pl. Grg. 458a, 470c (on readiness to be corrected to avoid error). On the significance of Socratic ideas of this type for Epictetus, see Long 2002: ch. 3, also note on 2.1. On readiness to change one's mind if shown wrong, compare 4.12, also 6.30.