Plato, Letters 362d

ἔθιζε οὖν αὐτοὺς καὶ ἀνάγκαζε φράζειν καὶ ταῦτα καὶ τὰ ἄλλα· σὲ γὰρ δεῖ εἰδέναι τε τὰ πάντα κατὰ δύναμιν καὶ κριτὴν εἶναι καὶ μὴ φεύγειν τὸ εἰδέναι. πάντων γὰρ ἄριστόν σοι ἔσται πρὸς τὴν ἀρχήν· τὰ γὰρ ἀναλώματα ὀρθῶς ἀναλισκόμενα καὶ ὀρθῶς ἀποδιδόμενα πρός τε τἆλλα καὶ πρὸς αὐτὴν τὴν τῶν χρημάτων κτῆσιν καὶ σὺ δὴ φῂς ἀγαθὸν εἶναι καὶ φήσεις. μὴ οὖν σε διαβαλλόντων πρὸς τοὺς ἀνθρώπους οἱ κήδεσθαί σου φάσκοντες· τοῦτο γὰρ οὔτε ἀγαθὸν οὔτε καλὸν πρὸς δόξαν σοι, δοκεῖν δυσσύμβολον

to declare these matters as well as the rest; for it is right that you should know the whole state of affairs so far as you can and act as the judge, and not avoid this knowledge. For such a course will best serve to enhance your authority. For expenditure that is rightly laid out and rightly paid back is a good thing—as you yourself maintain and will maintain—not only for other purposes but also for the acquisition of money itself. Therefore, do not let those who profess to be devoted to you slander you before the world; for to have the reputation of being ill to deal with is neither