Which friend encouraged C.S. Lewis to write science fiction?

J.R.R. Tolkien encouraged C.S. Lewis to write science fiction.

Lewis and Tolkien became close friends at Oxford, where both taught English literature and shared an interest in mythology, language, and imaginative fiction. Their conversations helped each writer develop work that later became highly influential, although their literary projects were distinct.

Tolkien’s encouragement contributed to Lewis’s decision to write The Space Trilogy, beginning with Out of the Silent Planet in 1938. Lewis, in turn, supported Tolkien’s creative work and read early versions of material connected with Middle-earth. Their friendship was part of the wider Inklings circle, which also included writers such as Charles Williams and Owen Barfield.

The two men eventually disagreed about some religious and literary matters, and their friendship changed over time. Still, Tolkien remained one of the most important personal influences on Lewis’s writing life. Their relationship is often remembered alongside their separate achievements in modern fantasy literature.