Obscurity of Satire

Joseph Addison (1672-1719), Dialogues on Medals, II:

For my part, says Cynthio, I am so far from Mr. Dryden's opinion in this particular, that I fancy Persius a better poet than Lucan; and that, had he been engaged on the same subject, he would at least in his expressions and descriptions have outwrit the Pharsalia. He was, indeed, employed on subjects that seldom led him into any thing like description, but where he has an occasion of showing himself, we find very few of the Latin poets that have given a greater beauty to their expressions. His obscurities are, indeed, sometimes affected, but they generally arise from the remoteness of the customs, persons, and things he alludes to: as satire is for this reason more difficult to be understood by those that are not of the same age with it, than any other kind of poetry. Love verses and heroics deal in images that are ever fixed and settled in the nature of things, but a thousand ideas enter into satire, that are as changeable and unsteady as the mode or the humours of mankind.