Dune, 50 years on: how a science fiction novel changed the world

"As for any inner meaning or 'message', it has in the intention of the author none. It is neither allegorical nor topical. As the story grew it put down roots (into the past) and threw out unexpected branches: but its main theme was settled from the outset by the inevitable choice of the Ring as the link between it and The Hobbit. The crucial chapter, "The Shadow of the Past', is one of the oldest parts of the tale. It was written long before the foreshadow of 1939 had yet become a threat of inevitable disaster, and from that point the story would have developed along essentially the same lines, if that disaster had been averted. Its sources are things long before in mind, or in some cases already written, and little or nothing in it was modified by the war that began in 1939 or its sequels."

   - Foreword : Lord of the Rings (JRR Tolkien)

It's a shame that the third book is so unrepentantly a young adult novel, by comparison to the much more mature first two books.