ἐφ' ἡμισείᾳ χρηστὸς εἶναι

From LSJ

ὡς μήτε τὰ γενόμενα ἐξ ἀνθρώπων τῷ χρόνῳ ἐξίτηλα γένηται → in order that so the memory of the past may not be blotted out from among men by time

Source

Greek > English (Woodhouse)

be honest by halves