High Quality Content by WIKIPEDIA articles! Soft science fiction, or soft SF, like its complementary opposite hard science fiction, is a descriptive term that points to the role and nature of the science content in a science fiction story. The term first appeared in the late 1970s and early 1980s and indicated SF based not on engineering or the "hard" sciences (for example, physics, astronomy, or chemistry) but on the "soft" sciences, and especially the social sciences (anthropology, sociology, psychology, political science, and so on). Another sense is SF that is more concerned with character, society, or other speculative ideas and themes that are not centrally tied to scientific or engineering speculations.