εὖ γὰρ ἴστε, ὦ ἄνδρες Ἀθηναῖοι, ὅτι οὐχ αἱ παλαῖστραι
οὐδὲ τὰ διδασκαλεῖα οὐδ᾿ ἡ μουσικὴ μόνον παιδεύει
τοὺς νέους, ἀλλὰ πολὺ μᾶλλον τὰ δημόσια κηρύγματα.
For you are well aware that it is not only by bodily exercises, by educational institutions, or by lessons in music, that our youth are trained, but much more effectually by public examples.
Aeschines, Against Ctesiphon (330 BC), III.246.