Characterization poses a special problem for science fiction writers.

In addition to establishing and resolving plot conflicts, they frequently attempt to create plausible imaginary worlds. Not surprisingly, then, writers often rely heavily on a limited gallery of stock characters — genius inventors, mad scientists, intrepid explorers, and gallant spacemen — who serve mainly to advance the plot or articulate the author's ideas or gimmicks. One of Sturgeon's main contributions to science fiction in the 1940s and 1950s (a contribution he was able to make perhaps because he frequently wrote other kinds of stories and thus lacked the narrow "ghetto" mentality of many science fiction writers) was to make psychological conflict central to the short story. Instead of characters who exhibit their creator's cleverness at inventing and solving intellectual puzzles (e.g. Asimov's robot stories) or who perform melodramatic feats of derring-do (as in countless "space operas"), Sturgeon emphasizes...