 The surviving histories speak equally positively of <unk> 's brief reign , although none offer a substantial commentary on his policies . Both <unk> <unk> and Aurelius Victor emphasize his wisdom and <unk> , with <unk> commending his decision to adopt Trajan as his heir . These views were later popularized by the 18th @-@ century historian Edward <unk> in his History of the Decline and Fall of the Roman Empire . <unk> considered <unk> the first of the Five Good <unk> , five successive rulers under whom the Roman Empire " was governed by absolute power , under the guidance of wisdom and virtue " from 96 until 180 . Nevertheless , even <unk> notes that , compared to his successors , <unk> may have lacked the necessary qualifications for a successful reign : 
