In a TV talk show (I think a program called “3 nach 9” in one German TV-Channel (Radiao Bremen (?)) in the late 1970s or early 1980s (I don’t remember), Lem said that there are two types of books, those that contain feelings and those that contain ideas.
Personally, I am more inclined to the books containing ideas, and Lem was one of the masters in this direction, writing some sparklingly intelligent books, mixing fiction with philosophy.
One of my favorite authors is Stanislaw Lem. One of my favorite books of him (and one of my favorite books in general) is “The Cyberiad”. Look here for a sample from that book (“How the world was saved”) explaining the real reason why the night sky is so empty: http://english.lem.pl/index.php/works/novels/the-cyberiad I am not sure this is really science fiction, certainly not in the normal sense of the word, but in a deeper sense, it might be the only type of fiction that really deserves that term.