All of Kurt Vonnegut's books are strongly satirical and ironical (Vonnegut often uses very dark humor), funny, compassionate and extremely wise. They mostly have a very poor plot (or none at all) and the emphasis is put onto the rather comic and pathetic characters. Kurt Vonnegut also very often uses science fiction and comic book formulas (quick action, short dialogues etc.), which usually puts his books onto bookstore shelves marked "sci-fi". Vonnegut, however, doesn't take the sci-fi elements with the same seriousness as the other sci-fi writers, and that probably makes the difference between his works and science fiction. I read and summarized three of his works: Cat's Cradle, Harrison Bergeron, and Slaughterhouse five. Through these stories Mr. Vonnegut argued through fate, the future, love, oppression and humanity. His descriptive writing style gives the reader a present sense impression of the story, and really makes you think. When you examine Cat's Cradle, Harrison Bergeron, and Slaughterhouse five you are given a good idea of Vonnegut a writer, because it provides a cross section of his ideas and the themes he is attempting to portray. .
The main thrust of Cat's Cradle seems to be toward the idea of fate. As a writer, he has been in charge of determining the fates for literally thousands of characters, and seems to have the idea in perspective. From the opening line, "Call me Jonah," to the end of the book when Bokonon tells Jonah to make a gesture to the gods, Vonnegut uses Herman Melville's Moby Dick as a symbol of fate. Every time the subject of fate is broached, especially with the Moby Dick references, it is a joke. In fact, one of the book's funniest scenes (at least as far as low humor is concerned) is Jonah's discovery of Mrs. Hoenikker's grave. That scene was probably also the single most cruel stab at Melville's masterpiece and the ideas it represented. Vonnegut was in this way trying to tell his readers that fate is foolish and to put any belief into it would be absurd.