Ass (refering to St. Francis's title of "Brother Ass" for the body) is exquisitely right becasue no one in his senses can either revere or hate a donkey. It is a useful, sturdy, lazy, obstinate, patient, loveable and infuriating beast; deserving now the stick and now a carrot; both pathetically and absurdly beautiful. So the body. There's no living with it till we recognixe that one its functions in our lives is to play the part of buffoon....Lovers...feel an element not only of comedy, not only of play, but even of buffoonery, in the body's expressoin of Eros. And the body would frustrate us if this were not so. It would be too clumsy an instrument to render love's music unless its very clumsiness could be felt as adding to the total experience its own grotesque charm -- a sub-plot or antimasque miming with its own hearty rough-and-tumble what the soul enacts in statelier fashion.
I won't deny that the body sometimes has its own ideas about what's appropriate at what times, regardless of what one wishes it would do. Lewis is enjoyably apt when he speaks a few paragraphs earlier about bodily desire striking at the most inopportune times and then deserting one when external circumstances seem to be perfect. Still, I don't know that the fact that our bodies are not completely under the control of our wills means that their main role is to be the comic double to our souls in terms of sex.
After all, one can't have sex without the body, no matter how you slice it. And if sex is the earthly expression of the love of Christ for his bride, the Church, then there must be an inherent dignity in the act itself that is more than a matter of souls uniting. Lewis's attempts to give the physical act of sex a dignity of it's own lead him to pontificate on what he calls the "Pagan Sacrament" of sex: man as Sky-Father and woman as Earth-Mother, enacting an age-old ritual. Uh, sure, but I don't really know that one has to reach out quite that far to bring the bodily aspects of sex in line with the sublime symbolism of the act. After all, God made our bodies and proclaimed them good, so the reality that the most intimate expression of human love involves our bodies shouldn't be a surprise.
Lewis doesn't seem to think that the bodily aspects of sex are transcendent, but merely mirror on a human level what's taking place spiritually. In these enlightened "Theology of the Body" days I think that we (as Catholics anyway, and Lewis wasn't) have moved to a more integrated and complete view of all elements of human sexuality. Not that I'm pitting myself or my theological insights against Lewis, mind you.