On Friday, Maggie Gallagher and I had a conversation on Blogginheads in which we continued our attempt to, as she puts it so brilliantly, “achieve disagreement” about whether it is good or bad to gender-neutralize marriage’s entrance rules—i.e., to allow same-sex couples the freedom to marry. Maggie, as you may know, is one of the chief opponents of same-sex marriage, and has made arguing against our marriages a large part of her career. As you also know, just three days before we spoke, the pro-marriage equality side had won four different state referenda by about 52-48. Maggie was generous in loss; looking at the video, I am embarrassed to say I was testy and not as generous in return. I will apologize. At the same time, I do think our differing philosophies of marriage become clearer and clearer. She is correct in that hers is losing. As she says, “the fact that sex between men and women makes babies is the central fact about it.” She believes that the purpose of marriage is to...