Here is an interview with R. Scott Bakker, wherein he talks about epic fantasy, world creation, religion, philosophy, and why fantasy is important in the modern world.
Here's an excerpt:
For instance, take the ancient Middle-East as described in the Bible. If you were to redraw the shorelines, rivers, and mountain ranges, and to rename the various peoples, nations, and cities -- to change everything, that is, except its fundamental form -- what would you have? A prescientific world where magic and prophecy are possible, where divinity is certain, where individuals have an indisputable place in a cosmic order, and where the end of the world is imminent.
What you would have, in other words, is something very similar to Eärwa or Middle-Earth! And this is my point: if you change the details and leave the fundamentals intact, scriptural worlds become fantasy worlds.
Personally, I find this fact extraordinary. It explains, for instance, why so many Biblical literalists have so much difficulty with Harry Potter. If you think the world as described in the Bible is the world, then Harry's world is no longer 'harmless fantasy' -- he might as well be a gunslinger! And it also explains, I think, something of epic fantasy's mass appeal.
And a little more:
So, to finally answer your question (I told you I spent way too much time mulling these things over!). Thanks to science, fantasy worlds are worlds where philosophy and religion still command the heights of cognition. In other words, any world where philosophical discourse remains entirely credible is a fantasy world -- which is why I think fantasy is ideally suited to be a 'literature of ideas.' To write the one, I've found, is to inevitably beg the other. I started using my philosophy to understand my fantasy, only to find my understanding of philosophy transformed as well.Speaking of fantasy and world creation, one of my favorite sites is Virtual Verduria. The work put into this is quite compelling, certainly on the level of a Tolkien or an Austin Tappan Wright, author of Islandia. Verduria has it all. History. Conlangs. All the cool stuff. Highly recommended.
And of course, taking world creation in a slightly more disturbing (because of thematic content, i.e. little girls with penises being vivisected and killed in battles) and outsider art direction, there's this link over at Metafilter, about Henry Darger, and the obsessive and astounding 15,000 page illustrated novel that he wrote over years.