"Common Time" is a science fiction short story written by James Blish. It first appeared in the August 1953 issue of Science Fiction Quarterly and has been reprinted several times: in the 1959 short-story collection Galactic Cluster; in The Testament of Andros (1965); in The Penguin Science Fiction Omnibus (1973); and in Isaac Asimov Presents the Great SF Stories.The story is considered to be an archetype of symbolism in science fiction.