[Canadauni]

Probably, Tolkien and Lewis are often noted as being friends. Tolkien regularly gave friendly criticism of Lewis's frequent use of obvious allegory. The main character in the Out of the Silent Planet series is noted as being based on Tolkien.

[duskwuff]

As an aside, a fun fact: Out of the Silent Planet was the result of a challenge between Tolkien and Lewis, in which Tolkien would write a book about time travel, and Lewis a book about space travel. Tolkien's attempt was The Lost Road -- a work which he never completed, but which appears in fragmentary form in the collection The Lost Road and Other Writings.