I have read elsewhere (and I don't have the time or inclination to look up the source) that C. S. Lewis supposedly believes that hell is "a state of mind." This assertion, at least in the location where I read it, was written by a self-professed evangelical Christian who wanted to discredit what he saw as his co-religionists' misplaced praise of Lewis.
While I do believe their praise is misplaced because he did not really espouse the causes or the outlook that many evangelicals claim to believe in (he once wrote....I believe it was in "Mere Christianity"....that even though he believed homosexuality is a sin, he had no right to judge homosexuals because he, not being one, was not himself subject to the temptations and virtues of being gay, not exactly the official, DOCTOR Dobson sanctioned stance), this person had it wrong about Lewis's conception of hell, at least if his work "The Great Divorce" is any indication.
In that story--I hesitate to say "allegory," because Lewis had a very precise definition of allegory and claimed that none of his writings, save for "Pilgrim's Regress" (unread by me) was properly "allegorical"--the narrator has a dream where he visits hell. He finds it is full of people who cannot live with each: they reside in isolation: no neighborhoods, no community. Each claims, more or less, to be self-sufficient and each is prey to blaming others for his or her problems. (In one scene, the narrator is on a bus in hell and a stranger tries to force him (the narrator) to read his (the stranger's) poetry.....quite humbling food for thought given my own poetic aspirations.) To top it all off, the people in hell either don't know they are in hell, or they vaguely realize it but find it so much more interesting than they imagine heaven to be. The story goes on when the narrator and a few of hell's inhabitants take an excursion to heaven, where everyone is much larger, much more "complete" and much stronger than the shadowy people from hell. Indeed, heaven is so much more "real" that it hurts the hellites even to walk upon the ground (as it might hurt one to walk barefoot along a gravelly road).
To me, this story suggests Lewis believed that hell is a state of being and not merely a state of mind. (In his other writings--I believe in "Mere Christianity"--he also says that hell is the principle of death counterposed to the principle of life, i.e., heaven. In other words, by focusing on what I see as Lewis's notion of hell as a state of being, I acknowledge that I am bracketing what for him was probably the more important distinction of eternal life versus eternal death, a distinction I'm not sure I believe in, since I don't know if I believe in eternal life.) The state of being is one of pride, or extreme introversion and egocentrism, the belief that the universe revolves around oneself (as, in the Christian scheme of the world, the universe revolves around God). In other words, the essential sin that lands people in hell is their choice to try to make themselves the center of the universe, to make themselves "as God."
How many evangelicals would fully buy into this notion of hell? Maybe a lot; maybe a majority. But I do wonder whether the DOCTOR Dobsons of the world would. They have, and I stand to be corrected, set up a universe that revolves around themselves.