The Postscript of Out of the Silent Planet is an interesting literary device. In it, the protagonist, Ransom, corresponds with the fictionalized and actual author of the story, "Lewis," or C. S. Lewis. There is an ongoing correspondence between them and Ransom is responding to a letter from Lewis. We can tell this because of a few things, especially Ransom's comments:
- "I agree, it is a pity I never saw the pfifltriggi at home."
- "Now as to your most annoying question ...."
These clearly indicate a give-and-take correspondence in which the Postscript is the latest response. This device serves several purposes along with allowing C. S. Lewis to poke a little fun at the fiction writing process as he speaks through the perceptions of his own protagonist. This device serves the purposes of:
- reinforcing the fiction-though-truth aspect of the story by providing a conversation between the witness of events and the chronicler of events.
- elaborating on (1) Ransom's perceptions of the Malacandrian world and on (2) the metaphorical battle between good and evil depicted in the story.
- expounding some of C. S. Lewis's own philosophical positions, such as the correct view to take toward lower forms of "irrational" animal life.
Ransom admits to being homesick for Malacandria (Mars) now that he is on Earth just as he was homesick for Earth while on Malacandria. He agrees with Lewis's decision to "telescope" the five weeks he spent living with the hrossa, especially Hyoi, to make the story better, yet laments the need to do so because it was in that time that he grew to know them.
I know them, Lewis; that's what you can't get into a mere story. For instance, because I always take a thermometer with me on holiday ... I know that the normal temperature of a hross is 103 degrees.
Ransom mildly laments or reprimands and corrects Lewis's decisions on a few points:
- "the three species" of Malacandria are not "perfectly homogeneous."
- though it is a pity Ransom never spent time with the pfifltriggi, it is important not to invent a visit with them, not "to introduce any mere fiction."
- though not as a correction of Lewis's information, Ransom laments the imperfect knowledge on Earth of the geography of Malacandria (Mars).
- responding to an annoying question, Ransom says eldil were correctly described as having "superior intelligence."
- questions Lewis's decision to ignore the "problem of eldil speech."
- specifies that Oysara are different from Earth's angels: "or whether he meant that they were ... some special military caste (since our poor old earth turns out to be a kind of Ypres Salient in the universe), ...."
- chides Lewis for omitting the account of the spacecraft's window shutters jamming just prior to their landing on Malacandria and challenges Lewis's theory of readers perceptions: "I don't believe your theory that 'readers never notice that sort of thing.' I'm sure I should."
- laments that the scene of a Malacandrian morning and procession to a hrossa funeral was omitted: "They go down, singing, to the edge of the lake. The music fills the wood .... For in that world, ... no one dies before his time."
- laments that the nocturnal (night) scene of lake swimming under a dark Malacandrian sky with a rising Milky Way was omitted: "the Milky Way ... rising like a constellation behind the mountain-tops--a dazzling necklace of lights ...."