τρεπτέον
From LSJ
ἀσκεῖν περὶ τὰ νοσήματα δύο, ὠφελεῖν ἢ μὴ βλάπτειν → strive, with regard to diseases, for two things — to do good, or to do no harm | as to diseases, make a habit of two things — to help, or at least, to do no harm
English (LSJ)
(τρέπω)
A one must turn, ποίαν ὁδὸν νὼ τ. Ar.Eq.72; ἐπί τι Pl.R.365c.
