A gloss on Greek prose style; probably (as Adler suggests) specifically on Plato, who was fond of such argumentative phrases in his dialogues, and uses e)/xe dh/ fifteen times. (He also uses the first of these glosses, a)/ge dh/, six times. However, he apparently never uses a)/ra dh/; and although he uses pro/sexe eight times, the direct object to\n nou=n is present in seven of the instances (i.e. 'apply your mind') while pro/sexe is used absolutely only in one of the disputed Letters (319A).)
Very similar entry in Photius, Lexicon epsilon2483, which however, instead of the Suda's second gloss a)/ra dh/ ('so then'), has o(/ra dh/ ('consider then'), a phrase used twenty-three times by Plato.