ἃ γὰρ δεῖ μαθόντας ποιεῖν, ταῦτα ποιοῦντες μανθάνομεν → what we have to learn to do we learn by doing
ăciscŭlārĭus, ĭī, m., tailleur de pierres : Gloss.
ἀκισκλάριος
aciscularius acisculari(i) N M :: worker with an adze; stone-cutter?