In Part I, we saw that there were reasons to question the conventional wisdom that homosexuality is innate, but that funding for research for an alternative explanation is not likely to flood the academies soon. In Part II, we saw that homosexuality, innate or not, can still be classified a sexual dysfunction because it channels the reproductive urge into a non-reproductive channel; if it isn’t innate, then it can (and should) be treated like any other dysfunction.
The foundation of my argument—that sex exists solely for procreation—was deliberately cast as a Darwinian argument; Catholicism doesn’t teach such a strict position. Indeed, the Church insists on the combination of both the unitive and procreative aspects of married love. I note with some amusement that the celibate St. Paul, that old puritan, counseled married couples to give in to one another, allowing for short breaks of mutually-consented restraint (1 Cor 7:5).