Magic realism
Great quote, Tom -- thanks!
I'm the only person I know of our generation with a love for well-written fantasy who still has not read the Narnia series. I have, however, read enough about it, and Lewis, and the Inklings, to be aware of the subtext.
It's perfectly consistent (not to mention satisfying) that Aslan wouldn't break his own rules. The higher powers created by Tolkein (another Inkling) for Middle Earth also refused to break their own rules, with a lot more at stake than merely appearing (see The Silmarillion).
I think the Inklings were onto something...