It’s almost always more incorrect than correct to say “Church” when you mean “hierarchy.” It’s especially misleading in the case of same-sex marriage, and Catholic support thereof.
The vocal public insistence of much of the hierarchy (Vatican, Irish, US) on the impossibility and the danger of same-sex marriage represents a dead end in Catholic moral theology. This is not to undercut the entirety of the moral theology — far from it. The notion that humans are created for relationships, that the power of procreation is deeply and sacredly connected to the love between men and women, that stable, loving families are a crucial element of a healthy society and one of the best possible situations in which to bring up children — these and other aspects of Catholic teaching on human sexuality are a potentially great — even essential — gift to the world.
For it is also hard to argue that contemporary society has given rise to a view of human sexuality that’s unambiguously conducive to human flourishing. The commodification of young bodies, whether in advertising or pornography or trafficking; the deep-rooted, vicious misogyny unleashed at the drop of a hat on every web site with a comments section; the widespread acceptance of the notion that sex need not involve real mutuality, commitment, even consent — these and other current realities disregard human dignity in favor of the unconstrained pursuit of some other ostensible good: profit, autonomy, pleasure, freedom.
On these and other issues, I happily listen to the hierarchy teach the wisdom of Catholic tradition. But I have come to believe that in including the issue of same-sex marriage in this list, they are making a significant category error. It is not an error that invalidates the moral tradition from which it emerged. All traditions that have deep roots give rise to multiple branches and offshoots, and some of those shoots eventually become dead ends. They are connected to the original roots, but they do not themselves bear good fruit nor help preserve the life of the tree.
Available at: http://works.bepress.com/una_cadegan/7/