Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
rătō: adv. ratus,
I certainly, surely (postclass.), Tert. Anim. 35; id. ad Uxor. 2, 9.
rătō, adv., d’une manière valable : Tert. Anim. 35.