It's pretty easy to see that Brave New World is science fiction. Just read the first chapter. The world in which the novel takes place is highly imaginative and completely different from our own. Because it portrays a futuristic society in which, to put it bluntly, everything sucks, and also because this novel helped define the genre, we feel confident about labeling it as dystopian literature. The philosophical bit arrives in Chapters Seventeen and Eighteen, where the novel is often criticized for reading like a treatise in the form of dialogue. It gives the impression that Huxley wrote Brave New World to promote his own philosophical beliefs rather than to write a perfect exemplar of the novel form.