ἕτερος ἐξ ἑτέρου σοφός τό τε πάλαι τό τε νῦν → one gets his skill from another, now as in days of old
firmly: P. and V. βεβαίως, V. ἐμπέδως, P. ἀκινήτως; see immovably.
authoritatively: P. κυρίως.