When we know clearly, then should we discuss:
To guess is one thing, and to know another. (tr. E. H. Plumptre)
σάφ᾿ εἰδότας χρὴ τῶνδε μυθεῖσθαι πέρι·
τὸ γὰρ τοπάζειν τοῦ σάφ᾿ εἰδέναι δίχα.
τὸ γὰρ τοπάζειν τοῦ σάφ᾿ εἰδέναι δίχα.
Original text (Ancient Greek)