One reason Tolkien’s imaginary realm has proved so successful is precisely its structural non-specificity. What I mean is: Tolkien treats material that has deep roots in, and deep appeal to, various cultural traditions; but he does so in a way—as fictionalised worldbuilding rather than denominated myth—that drains away much of the poisonous nationalist, racist and belligerent associations those traditions have accumulated over the centuries. A thumbnail history would go like this: in the late 19th- and early 20th-centuries, Wagner’s Ring melodramas spoke to a great many people about a particular northern-European cultural identity; about a group of linked, potent emotional attachments to history, landscape, to the numinous and the divine, to matters of heroism and everyday life. I am trying not to sound sneery as I say this (I mean melodrama in the strict sense of the word), because these things did, and do, matter intensely and genuinely to many people. But there is a reason, a room-filling elephant of a reason, why Der Ring des Nibelungen no longer has this general resonance. It is because the cultural reservoir from which it draws much of its power also supplied cultural capital to the worst regime ever to take charge in Germany, and therefore lubricated the most catastrophically destructive war ever to be waged in the world. In saying this I am not, of course, blaming Wagner for the Nazis. Indeed, the endless debates about Wagner’s own ideological ‘purity’ (‘was Wagner an anti-semite?’ Short answer: yes. Long answer: yes, like just about every other gentile in 19th-century Europe) seem to me to miss the point. The restless churning through this question happens because we're desperate to acquit Wagner so that we can enjoy his music with a clean conscience. We ask the question, get the uncomfortable answer, and ask it again. In our guts resides the queasy comprehension that Wagner can’t be acquitted. Politics can’t be neatly separated out from the Ring cycle, leaving only a washed-and-scrubbed sequence of pretty orchestral tone poems behind. I love the Ring cycle, and listen to it regularly; but I would never try to deny that it is political all the way through, down to its very marrow. It is, to be precise, about the notion that history and myth are in some sense the same thing—a very dangerous notion indeed.
Tolkien’s story is not the same as the Ring cycle; his ‘ring’ (as he crossly reminded correspondents) not the same as Alberich’s ring. But a considerable amount of the heft and force of Lord of the Rings derives from the way Tolkien draws on the same broader cultural, mythic, northern-European heritage. What saves Lord of the Rings is that it is not about Germany, or about England; or to be more precise, that it is about England and Germany only secondarily, in an eloquently oblique (a cynic might say: in a plausibly deniable) manner. Tolkien found a way of articulating the same deep-rooted cultural concerns in a way that avoids being poisoned by the cultural specificity of European Fascism. This doesn’t let Tolkien off the hook, as far as racial and ideological content goes, of course. Indeed, I offer my thoughts here not as a value judgement of his fiction, so much as an explanation for why Lord of the Rings has done so extraordinarily well—resonated so powerfully with so many people—in the postwar period. It rushed in to fill the gap that more culturally-specific art had supplied before that kind of art was discredited by the 1940s.
I wonder if this is a broader cultural phenomenon. We prefer stories of Marvel superheroes to actual stories of 'crime fighters' (policemen, soldiers and so on) because we have lost faith in the latter, or more precisely lost faith that the latter can ever exhibit the kind of perfect heroism we want our stories to articulate. Hogwarts, being fictional, can apprehend something very important -- school -- without being tangled in the messy specificity of actual real-world schooling. A sequence of novels set in Eton would be noisome; although that is, in effect, what Rowling has written. The twentieth-century has cured us of our attachment to a certain kind of ideology-text; and the cure we have chosen is -- worldbuilt fiction. (I could add lots of other examples, from West Wing to Westeros. But I've probably said enough.)
‘Could a rule be given from without, poetry would cease to be poetry, and sink into a mechanical art. It would be μóρφωσις, not ποίησις. The rules of the IMAGINATION are themselves the very powers of growth and production. The words to which they are reducible, present only the outlines and external appearance of the fruit. A deceptive counterfeit of the superficial form and colours may be elaborated; but the marble peach feels cold and heavy, and children only put it to their mouths.’ [Coleridge, Biographia ch. 18]
‘ποίησις’ (poiēsis) means ‘a making, a creation, a production’ and is used of poetry in Aristotle and Plato. ‘μóρφωσις’ (morphōsis) in essence means the same thing: ‘a shaping, a bringing into shape.’ But Coleridge has in mind the New Testament use of the word as ‘semblance’ or ‘outward appearance’, which the KJV translates as ‘form’: ‘An instructor of the foolish, a teacher of babes, which hast the form [μóρφωσις] of knowledge and of the truth in the law’ [Romans 2:20]; ‘Having a form [μóρφωσις] of godliness, but denying the power thereof: from such turn away’ [2 Timothy 3:5]. I trust that's clear.
There is much more on Coleridge at my other, Coleridgean blog.