Knowledge must come through action; thou canst have no test which is not fanciful, save by trial.
ἀλλ᾿ εἰδέναι χρὴ δρῶσαν· ὡς οὐδ᾿ εἰ δοκεῖς
ἔχειν, ἔχοις ἂν γνῶμα, μὴ πειρωμένη.
ἔχειν, ἔχοις ἂν γνῶμα, μὴ πειρωμένη.
Original text (Ancient Greek)