The description "soft" science fiction may describe works based on social sciences such as psychology , economics , political science , sociology , and anthropology . Noteworthy writers in this category include Ursula K. Le Guin and Philip K. Dick .   The term can describe stories focused primarily on character and emotion; SFWA Grand Master Ray Bradbury was an acknowledged master of this art.  The Eastern Bloc produced a large quantity of social science fiction, including works by Polish authors Stanislaw Lem and Janusz Zajdel , as well as Soviet authors such as the Strugatsky brothers , Kir Bulychov , Yevgeny Zamyatin and Ivan Yefremov .  Some writers blur the boundary between hard and soft science fiction.