I define science fiction as the art of the possible. Fantasy is the art of the impossible. Science fiction, again, is the history of ideas, and they're always ideas that work themselves out and become real and happen in the world. And fantasy comes along and says, 'We're going to break all the laws of physics.' ... Most people don't realize it, but the series of films which have made more money than any other series of films in the history of the universe is the James Bond series. They're all science fiction, too - romantic, adventurous, frivolous, fantastic science fiction!
Ray Bradbury