"For a real discussion rather than just a rallying of supporters, the writers need to come back with a theological alternative to Natural Law as a basis for the formation of conscience."

Actually, as I've said before on these boards, Natural Law simply needs to undergo a much-needed evolution when it comes to human sexual behavior. As it stands, it's stuck in the 13th century. Because Thomas Aquinas never himself observed animals of the same sex engaging in sexual behavior he deduced that same-sex behavior is "against nature." Since homosexuality is extant in every species of the animal kingdom it is clearly not "against nature." So the church has not evolved in its thinking on this one issue even though it has evolved on many other aspects of scientific inquiry. It's as though the church has held its collective ears and shouted, "NO! WE DON'T WANT TO CHANGE!" And so it has remained stuck. Let Natural Law evolve and you won't have to throw out the theological baby with the bath.