This is C.S. Lewis's response to William Blake's "The Marriage of Heaven and Hell". Unlike Blake, Lewis believed that good and evil need not and should not be together in an eternal Gordian knot. As Lewis says in his introduction, "Evil can be undone, but it cannot "develop" into good. Time does not heal it ...If was insist on keeping Hell (or even Earth) we shall not see Heaven: if we accept Heaven we shall not be able to retain even the smallest and most intimate souvenirs of Hell." Like Blake's work, Lewis's book is the account of a dream - a mixture of fantasy, fable and parable, with a Bunyan-like cast of "everymen".