C.S. Lewis was clear about his biblical views on homosexuality. At one point he wrote, "I take it for certain that the physical satisfaction of homosexual desires is sin. This leaves the homo. no worse off than any normal person who is, for whatever reason, prevented from marrying." But this didn't stop Lewis from building and maintaining a long and close friendship with Arthur Greeves, a man who was honest with Lewis about his same-sex attraction.

The two met when they were boys and bonded over a shared love of Norse mythology. "Many thousands of people," Lewis would later write, "have had the experience of finding the first friend, and it is none the less a wonder; as great a wonder … as first love, or even a greater." For the next several decades, until the end of Lewis' life, the two would maintain their friendship in spite of geographical distance, a gap in intellectual aptitude, and other trivial and not-so-trivial differences and disagreements.

Arthur Greeves admitted at some point to Lewis that he was a homosexual. But as far as the textual record goes, there is no evidence that this ever proved to be an impediment to their intimacy. Lewis certainly didn't try to distance himself from Greeves on account of it, as if he needed to hold himself aloof from Greeves's complex feelings—which may, in any case, never have been directed toward Lewis at all—in order to keep himself from learning too much about his friend's personal life.

On the contrary, their letters are filled with the affection of a deep friendship. In what turned out to be the final year of Lewis' life, he was planning a holiday with Greeves in Ireland. When a heart attack prevented Lewis from keeping those plans, he wrote in the final letter he ever sent to Greeves, "It looks as if you and I shall never meet again in this life. This often saddens me [very] much." And then, in the letter's last line, "Oh Arthur, never to see you again!" Their letters still serve as a model for what friendship between a gay man and a heterosexual sympathizer and confidant might become.