The idea of retelling the myth of Cupid and Psyche, with the palace invisible, had been in C.S. Lewis's mind ever since he was an undergraduate; the retelling, as he imagined it, involved writing through the mouth of the elder sister. He argued that this made the sister not simply envious and spiteful, but ignorant (as any mortal might be of the divine) and jealous (as anyone could be in their love).
He tried it in different verse-forms when he considered himself primarily a poet, so that one could say that he'd been "at work on Orual for 35 years," even though the version told in the book "was very quickly written." In his pre-Christian days, Lewis would imagine the story with Orual "in the right and the gods in the wrong."
Origin of title
Lewis originally titled his working manuscripts "Bareface", with the interplay of multiple meanings: Orual's facial deformity, which she hides with a mask; Psyche's mortal beauty; and the invisible gods Cupid and Aphrodite, who are supposedly the most beautiful of all in Greek mythology. There is also the "bare-faced lie" of the gods; and the "plain truth" of her argument, as Orual sees it in the beginning. The word "face" also refers to the original myth, in which Psyche was not allowed to see Cupid's face, so her intimate encounters with him would be veiled in darkness. The working title "Bareface" also suggests the anonymity of the dark and of "Everyman" looking to see the face of god.
The editor (Gibb) rejected the title "Bareface" on the ground that readers would mistake it for a Western. In response, Lewis said he failed to see why people would be deterred from buying the book if they thought it was a Western, and that the working title was cryptic enough to be intriguing. Nevertheless, Lewis started considering an alternative title on February 29, 1956, and chose "Till We Have Faces", which refers to a line from the book where Orual says, "How can [the gods] meet us face to face till we have faces?" He defended his choice in a letter to his long-time correspondent, Dorothea Conybeare, explaining the idea that a human "must be speaking with its own voice (not one of its borrowed voices), expressing its actual desires (not what it imagines that it desires), being for good or ill itself, not any mask."