"When I was writing Dune there was no room in my mind for concerns about the book's success or failure. I was concerned only with the writing. Six years of research had preceded the day I sat down to put the story together, and the interweaving of the many plot layers I had planned required a degree of concentration I had never before experienced. It was to be a story exploring the myth of the Messiah. It was to produce another view of a human-occupied planet as an energy machine. It was to penetrate the interlocked workings of politics and economics. It was to be an examination of absolute prediction and its pitfalls. It was to have an awareness drug in it and tell what could happen through dependence on such a substance. Potable water was to be an analog for oil and for water itself, a substance whose supply diminishes each day. It was to be an ecological novel, then, with many overtones, as well as a story about people and their human concerns with human values, and I had to monitor each of these levels at every stage in the book. There wasn't room in my head to think about much else."