Isaac Asimov was criticized for the general absence of sexuality and of extraterrestrial life in his science fiction. Asimov once explained that his reluctance to write about aliens came from an incident early in his career when Astounding's editor John Campbell rejected one of his early science fiction stories because the alien characters were portrayed as superior to the humans. He decided that, rather than write weak alien characters, he would not write about aliens at all. Nevertheless, in response to these criticisms he wrote The Gods Themselves, which contains aliens, sex, and alien sex.