ἐπῖ τῶν καθόλου λόγων. The phrase is equivalent to the Latin Rationalis or Procurator summæ rei, an official who had charge of the imperial finances, and who might be called either treasurer or finance minister. The position which Macrianus held seems to have been the highest civil position in the empire (cf. Valesius’ note ad locum). Gibbon calls him Prætorian Prefect, and since he was the most famous of Valerian’s generals, he doubtless held that position also, though I am not aware that any of our sources state that he did.