Founding Father

Story, first published: Galaxy Science Fiction, May 1957

The hero of "Founding Father" is a mutant immortal who lands on a planet to found a colony after a century in space. To preserve his sanity on the trip, Earthlings provided him with a dimensino, a machine that deluded him with imaginary companions to pass the time. Winston cannot totally dispel the illusion even after his robots tell him the truth. The story ends ambiguously: "He heard steps on the stairway, the sound of many happy, friendly voices, coming up to get him"

Ewald, Robert J.: When the Fires Burn High and the Wind is from the North, p.70-71