[Aiwendil]

Any 'sincere' form of spirituality expressed through art faces a kind of double-whammy - on the one hand, the pressure to be inclusive and non-confrontational; on the other, to avoid ridicule or deconstruction by postmodern cultural critique.

That such art will inevitably experience both of these criticisms does not mean that the artist need anticipate them and take them into account. Tolkien was certainly not worried about either of these, and his work reflects neither pressure.

You do have a point though - perhaps one reason no modern fantasy is imbued with the same heroic spirituality as Tolkien's is that modern authors do give in to one or both of those pressures. The safest course seems to be to avoid any spirituality at all, and that is what most modern hacks do.

But we really are talking about swords-and-sorcery fantasy, aren’t we? That’s what we’d like to see a new, seminal example of, right?

I think so, and that's exactly why I think the genre is constricted. In practice, the fantasy genre consists (with a few exceptions) of Tolkien imitation. How far away from the "sword and sorcery" style can one get before it's not fantasy any longer?

Tolkien traded on the same “Mental Real Estate” in his day, starting with The Hobbit, which offers familiar and accessible elements (Dragons, Wizards, Elves, Dwarves, magic rings, etc.; also classic mythic motifs) reworked in a new and innovative (at the time, anyway) form. I would add to the article author’s theory that not only do you need a points of accessibility like that, you also need to offer some fresh spin on them.

I'm not sure whether this kind of "mental real estate" is the same as that in Harry Potter. Wizards and dragons are fundamentally unlike school - the latter draws on actual experience, the former do not. Still, I think you have a point about Tolkien. I'm just not sure whether the analogy to Harry Potter is precise.

I thought that the Ideal Forms usually represented the essence of concrete things

I thought it could apply to qualities - beauty, for instance. I certainly could be wrong however. Regardless of how Plato used the concept, I'm using it to refer to art - and I think it's a valid application.

I’m tempted to muse that since the forms of various artistic mediums vary, the Platonic essence common to them all must have something to do with content.

But what about, for example, Beethoven's 5th symphony? There's no real content, if by content we mean allegory/applicability. Whatever the purpose of art is, it must be the same for both music and literature. Unless you want to consider one of those media not to be art, you must define the purpose of art as something common to both of them.