διατριπτέον
From LSJ
τὸ δὲ ποιεῖν ἄνευ νοῦ ἃ δοκεῖ καὶ σὺ ὁμολογεῖς κακὸν εἶναι: ἢ οὔ → but doing what one thinks fit without intelligence is—as you yourself admit, do you not?—an evil
English (LSJ)
A one must spend time, Arist.Rh.1417a10, Men.Rh. p.359 S. II one must rub, Hippiatr.1.
Greek (Liddell-Scott)
διατριπτέον: ῥημ. ἐπίθ. τοῦ διατρίβω, Ἀριστ. Ρητ. 3.16,6.