Why did Bloomsbury U.K. eventually decide to offer “Harry Potter” books in disguised covers? Because people were ashamed to be seen reading about witches and wizards on the train. Fantasy had been made into a guilty pleasure, like pornography. It was immature, juvenile, escapist. As for all those Tolkien fans who liked to dress up as elves and orcs, the only explanation, spluttered Edmund Wilson in 1956, was that “Certain people . . . have a lifelong appetite for juvenile trash.” This, Michael Saler remarks, “from a man who liked to be called ‘Bunny.’ ”

In “As If: Modern Enchantment and the Literary Prehistory of Virtual Reality,” a historical and cultural study of fiction fandom, Mr. Saler counterpunches vigorously against the whole edifice of literary snobbery. What he has to say is so self-evidently right that the fact he has to say it makes one wonder how the critical profession has managed, for so long, to cultivate such a large blind spot. His book should be essential reading in every graduate school of the humanities. But it’s much more fun than that recommendation suggests. More..