Percy Bysshe Shelley, from "A Defence of Poetry"

In his 1821 essay, “A Defence of Poetry,” discussing the good and bad effects of Christian faith on the imaginative history of humanity, Percy Shelley wonders whether “Dante and his rival Milton” were conscious of the gap that, for Shelley at least, must have divided their personal beliefs from the orthodoxies and superstitions of their audiences. Milton's portrait of Satan is key to Shelley's speculations about this question.

Milton's poem contains within itself a philosophical refutation of that system of which, by a strange and natural antithesis, it has been a chief popular support. Nothing can exceed the energy and magnificence of the character of Satan as expressed in Paradise Lost. It is a mistake to suppose that he could ever have been intended for the popular personification of evil. Implacable hate, patient cunning, and a sleepless refinement of device to inflict the extremest anguish on an enemy, these things are evil; and although venial in a slave are not to be forgiven in a tyrant; although redeemed by much that ennobles his defeat in one subdued, are marked by all that dishonours his conquest in the victor. Milton's Devil as a moral being is as far superior to his God as one who perseveres in some purpose which he has conceived to be excellent in spite of adversity and torture is to one who in the cold security of undoubted triumph inflicts the most horrible revenge upon his enemy, not from any mistaken notion of inducing him to repent of a perseverance in enmity, but with the alleged design of exasperating him to deserve new torments. Milton has so far violated the popular creed (if this shall be judged to be a violation) as to have alleged no superiority of moral virtue to his God over his Devil.

 — From “A Defence of Poetry” (1821)