Every book reflects the beliefs of its author, at least indirectly. But some books are the very apotheosis of their authors' philosophies, often containing long sections devoted to ethical or moral analysis. Here's what it looks like when your favorite authors get philosophical.
Monomania is a trait shared by science fiction authors and science fiction fans. One group writes books about their obsessions, and the other makes those books into their obsessions. Over time, the latter can get quite a good picture of the philosophy of the former. These aren't always the fan favorite books, nor the most popular ones by a given author. Instead, they are a sort of symbolic culmination of all the ideas that float around inside the authors' heads. Some books just seem to be the embodiment of different author's philosophies.
Science fiction works are often set against a backdrop of politics, but not everyone makes those politics the central point of their novels. These authors are obsessed with what makes society tick, rather than what makes people tick.
One of the best books to demonstrate this is Railsea, by China Miéville. Railsea is neither his best book nor his most popular book, but the twist at the end perfectly explains what many of Miéville's books are about. The book is an homage to Moby Dick, set on a dust sea criss-crossed by rails which trains use to hunt giant moles. Why the rails are there, and how they are maintained, is the subject of much speculation - most of which is religious in nature. When one train heads to the end of the rails, they battle mechanical "angels," and discover a moldering city of the gods. There, the descendants of the great engineers who built the rails wait, with bills that they expect to be paid with interest. Miéville has been open both about his atheism and his socialism, and while these come out in most of his books, no other book so suddenly represents both ideas. One of the characters literally turns to the capitalist gods and says, "We owe you nothing."
Railsea is a young adult book, and, while it's not an attempt at propaganda, it has the vehemence of youthful idealism. Its whole purpose, after a long, strange journey, is to let kids know that no matter how weird and seemingly anarchic their adventures are, there are social and economic forces underpinning everything, and those forces have a bill handy.
Another book falls into this category, far more than some people realize is Do Androids Dream of Electric Sheep? Philip K Dick was a mind-bogglingly prolific author, and this was his most famous work, but those who see Blade Runner only get part of the politics. Androids isn't just about humans and androids and quiet introspection about the nature of consciousness. Deckard, in the book, doesn't just have a electric femme fatale. He has an electric pet - a sheep. He knows its a machine, but can't bring himself to not care for it. He still wants a real animal to love. All humans do. With resources so scarce, having, and loving, a real pet is an aspiration and a status symbol. The question of real versus artificial isn't just something that's to be pondered by people deep into the night, it's a commodity and a part of society.
Two political books that I think duel (quietly) with each other are George Orwell's book, 1984, and Ursula K Le Guin's book, The Dispossessed. Both are tough reads by authors that take a square look at human nature and at politics, and believe that the latter arises, inescapably, from the follies of the former. They both seem to come to two semi-conflicting points. Although 1984 makes us watch the slow breakdown of a man's mind under the constraints of a totalitarian regime, it ends with an epilogue that makes it look like we've been reading a historical document of a time long past. The regime has ended. Orwell's uber-depressing political book ends with a wink - humans inevitably break down the chains that they make for themselves. It represents his hopes, as well as his fears.
The Dispossessed, on the other hand, takes a look at a anarchic society. Colonists go to a barren moon vowing to surrender possessions and rules, and even deliberately re-shape their speech, so that people will understand that they have no right to oppress other people. They will be totally free. Inevitably, power structures and methods of dealing with those who oppose those power structures, creep into this egalitarian society. Le Guin seems sure, in this and other writing, that we will always rebuild the chains that we have to escape.
While few authors leave politics completely out of their books, for many, the reality of their world isn't so much one of politics as it is one of experience. And they communicate that experience through style. That style conveys the feeling with which we are meant to walk away from the page, still buzzing. The most famous of these is probably William Gibson, who used Neuromancer to create the future aesthetic he wanted. He wasn't just an author, he was the leader of the charge of the cyberpunks, and his novel perfectly reflected that. Kurt Vonnegut, with Slaughterhouse Five, did the same. The novel might be considered political, but its cynicism and exploded narrative sidestep political treatise and turn it towards counterculture. In that way, it's a nearly literal representation of its author. Vonnegut and the protagonist both experienced the bombing of Dresden, and then the protagonist experiences literally the counterculture philosophy that Vonnegut turned to figuratively.
Like Vonnegut, Octavia Butler deals in areas that can be viewed as political, but that she tries to get readers to experience. This is uncomfortably evident in her book, Kindred, about a modern African-American woman who is transported, seemingly at random, back to a plantation in the American south in 1815. Butler said, of the book, "I was trying to get people to feel slavery. I was trying to get across the kind of emotional and psychological stones that slavery threw at people." Like Vonnegut and Gibson, her books are written in such a way to communicate the experience of a science fictional situation. Her goal was not to see slavery as a set of laws, but as a horror that could be unleashed on the body, the mind, and the heart. In order to understand, the reader has to experience it with the characters. The effects of different situations on the body, mind, and heart, run through many of her books, and although Kindred may be her most famous, the book that embodied her stylistic philosophy most is, Lilith's Brood. The Earth is destroyed ecologically, and physically repugnant yet strangely seductive aliens want to have sex with humans to rebuild a hybrid population. That could be the set-up for something cheap, but Butler's style makes it real, with all the immediate physical and emotional impact such a situation would have. The book represents her more than her more-famous work by being the book that allows her to share a body, and a world, with the reader.
And lastly, some people just decide to live their life and the books in unison. The philosophies that the books represent aren't political or aesthetic, but representations of the way the authors want to live their lives. These are books that come closest to enthusiasms, loves, and quirks of the authors that write them.
Although Ray Bradbury is best known for Fahrenheit 451, I think the book that carries the largest quotient of Bradbury's personal philosophy is The Martian Chronicles. This is a guy who said, "I have never listened to anyone who criticized my taste in space travel, side shows, or gorillas. When that happens I pack up my dinosaurs and leave the room." The collection of stories, some of the haunting science fiction tales, some of them stories of alien miracles, and some of them Poe-like tales of horror, contain as much relish as can be packed into a book. You can't tell me that Bradbury didn't spend at least one day pacing back and forth in his room muttering, "For the love of God, Montresor." These are stories that came from pure love.
Madeleine L'Engle's most famous book is A Wrinkle In Time, but although it deserves its reputation and its laurels, the book that packs as much L'Engle as it is possible to get between two covers is A Ring of Endless Light.
L'Engle's books were coming-of-age books back when coming-of-age didn't mean marrying a vampire or living in a dystopia, but opening yourself up to everything life had to offer. L'Engle opened up her heroes to everything all at once. Her books were filled to the brim with plots and themes, all about finding one's place in the world. A religious person in a genre not particular given to the type, L'Engle was both passionate and wholesome in her writing - and famously adopted a 'story as truth' philosophy when people asked her about the difference between fiction and memoirs. She liked her life crammed full of stuff, and her stories tended to get her heroes to a place where their lives are crammed full of stuff, too. A Ring of Endless Light included family fighting and forgiveness, three different love interests, an uncomfortable awareness of death, awakening sexuality, and technology that let the heroine communicate telepathically with dolphins. And it was only halfway through a series.
Possibly the most obscure book on this list is Douglas Adams' Last Chance to See. For the most part, Adams was a fiction writer. This book, however, was a series of nonfiction stories about Adams going around the world for a year with a zoologist, and checking out different critically-endangered species. Considering the strongly connected themes in Adams' other work (it's tragically ironic that so many of his books deal with a sort of cursed immortality when Adams himself died so far before his time), what makes this book so much him?
Adams himself listed it as his favorite, but I think the real clue as to why this represents him is in an answer he gave to an interviewer who asked him about the long gaps between his novels. He said that he had become wary of writing novels that contained jokes about scientists. He'd been listening to a tedious comic talking about how stupid scientists were, for some specious reason, and had a horror that his absurdist books might provoke the same feeling. That they would do such a thing is doubtful, as his enthusiasm for all the sciences shows in all his novels, but whenever he wrote about technology nerds, science breakthroughs, or gifted researchers, there was a wistfulness to the writing that showed through.
Last Chance to See was a book in which he had the bizarre adventures he wrote about in fiction - like trying to buy a condom as an improvised microphone cover in rural China, and after much miming to a shopkeeper, receiving birth control pills. But it also had him working with actual scientists, doing the kind of conservation work he was passionate about. His admiration for the scientists' work and their eccentricities shows through on every page. It's basically a book in which a fanboy is, for one year, given the keys to the kingdom. Although it will never be his most famous book, or even his best, its clearly the one that allowed him to revel in his own personal ideas of what life in general, and his life in particular, should be.