διαληπτ-έον · dialēpt-eon — LSJ
one must divide, τὰς ἐπιστήμας Pl. Plt. 258b; δ. ὡς . . we must distinguish and say that . ., Arist. Pol. 1290b9.
one must hold an opinion, form a judgement, τὸ παραπλήσιον δ. περί τινος Plb. 6.44.1, 11.25.3.
one must discuss, treat, Porph. Abst. 1.57.