Nobody - for good reason - has ever been able to say exactly where "fantasy" begins and ends. It is immensly larger than the current commercial category of books labeled Fantasy. It cannot be limited to "the impossible" or "magic", or "the supernatural". The origins of fantastic literature are lost to sight, because it is worldwide, and if myth and legend are included in it, it long predates history and literacy. It's permanent, it thrives, because it's infinitely adaptable.
Ursula K. Le Guin i introduksjonen.