Isaac Asimov’s reputation precedes him; his prolific output of science fiction novels and short stories between the 1940s and the 1990s, along with his many Hugo and Nebula awards, cemented his reputation as the premier science fiction author of his time. His writing, at least in the first half of his career, focused on “hard” science fiction: stories that were broadly founded in realistic science. Indeed, as well as writing fiction, he was a professor of biochemistry, and wrote a wide variety of popular science essays and books.

This collection brings together the few Asimov science fiction short stories that are currently known to have passed into the U.S. public domain, arranged in order of publication. It includes one focused on robots and the positronic brain, a subject that he would return to many times over his career.