In light of recent developments in the United States on the issue of gay marriage, I thought it would be interesting to revisit what C. S. Lewis thought about homosexuality. Lewis, who died in 1963, never wrote about same-sex marriage, but he did write, occasionally, about the topic of homosexuality in general. In the following I am quoting from my book, Mere Theology: A Guide to the Thought of C. S. Lewis. For detailed references and footnotes, you may obtain a copy from Amazon, your local library, or by clicking on the book cover at the right....
In Surprised by Joy, Lewis claimed that homosexuality was a vice to which he was never tempted and that he found opaque to the imagination. For this reason he refused to say anything too strongly against the pederasty that he encountered at Malvern College, where he attended school from the age of fifteen to sixteen. Lewis did not rate pederasty as the greatest evil of the school because he felt the cruelty displayed at Malvern to be a far greater sin. Lewis thought that pederasty was most attacked because it was the most disreputable and unmentionable sin, by adult standards, and because it was a crime in English law. He thought this attack was hypocritical.
Lewis also abhorred the modern notion that friendship between two men is unconsciously homosexual. He maintained that those who cannot conceive of friendship as a love, in and of itself, but only see friendship as a guise for Eros, show that they have never experienced true friendship. Lewis says that even kisses, tears and embraces are not necessarily signs of homosexuality. If they were, then the results would be too comic, for Johnson and Boswell embraced each other, and they were obviously both heterosexual.... Lewis suggests that if we do not have such demonstrations between male friends in our culture today, it is we, not our ancestors, who are out of step.
In regard to homosexuality Lewis believed that the physical satisfaction of homosexual desires is sin. This leaves the homosexual no worse off than the heterosexual who is prevented from marrying for whatever reason. According to Lewis, our speculation about the cause of homosexuality is not what matters. We have to rest content with ignorance. Lewis cites the case where the disciples ask Jesus why a certain man was born blind. The disciples were told that it was not because of the man's sin or his parents' sin that he was born blind. Rather, the man was born blind so that the work of God might be displayed in his life. (John 9:1-3) Lewis applies this to the condition of homosexuality and makes the point that every disability, homosexuality included, conceals a vocation. To discover this vocation the homosexual must accept sexual abstinence. Lewis speculates that the Christian homosexual might be able to provide a certain kind of sympathy and understanding to others that mere men and women cannot give. The Christian homosexual should not seek to evade this vocation through mock marriage to his own sex, even if carnal acts are not involved, nor should he wear the clothes of the other sex in private. Rather, the Christian homosexual must try to cultivate the duties, burdens and virtues of the other sex. In short, the tribulation of homosexuality, like all other tribulations, must be offered to God, and then he will guide.
Lewis did not think that homosexual acts should be considered criminal. He thought that of all sins in the world, homosexuality should be of least concern to the state. Lewis argued with regard to the homosexual issue that one is fighting on two fronts: for the persecuted homosexual against busybodies who have no right to know about this aspect of people's private lives, and for ordinary people against the highbrow homosexuals who dominate the world of criticism [literary criticism that is] and who won't be very nice to you as an author unless you are on their side.
It is quite possible that Lewis's views on homosexuality were influenced by his lifelong friendship with Arthur Greeves, a man who struggled with homosexual desires. Lewis's relationship with Greeves developed in him a deep compassion for the homosexual, especially the Christian homosexual. However, Lewis did not allow this relationship to alter his biblical understanding of homosexual practice as a sin.
(References: Surprised by Joy, pp. 89, 101, 108-109; The Four Loves, pp. 90-94; Vanauken, A Severe Mercy, pp. 146-147; Lewis & Hooper, Letters of C. S. Lewis, p. 281 (February 1, 1958), p. 292 (May 17, 1960); see also Lewis's letters to Arthur Greeves in They Stand Together and The Collected Letters of C. S. Lewis, Volumes I-III.)