...the Lockean settlement was obviously a long time ago, and most of today's liberals no longer believe in the "endowed-by-their-Creator" theory of human rights. Which is why abortion has become such a flashpoint - because it's the place where modern liberals have instituted a utilitarian approach to killing in place of the older natural-rights-based understanding, and the place where Christians are resisting. This explains, in turn, why pro-lifers make liberal arguments even though the source of their conviction is usually religious: it's not because they're dishonestly concealing their Christianity, but because they still think that rights-based liberalism is the common ground between Christians and secularists, and so they naturally attempt to argue on that ground. And the current pro-life frustration, I think, flows from the fact that pro-choicers have half-abandoned this common ground, but often won't admit it. Hence the constant talk about slippery slopes and infanticide from my side of the debate: it's not because we necessarily think America is about to legalize infanticide, but because we're trying to demonstrate to the pro-choice side that they only have one foot left in rights-based liberalism, and that there are some pretty awful things waiting where they've put their other foot down.
All public ethics are equivocal mishmashes, but some mishmashes are more equivocal than others. The so-called Lockean settlement has its flaws, as Daniel Larison shows, but like many I'm wary of exchanging it for its likely successors.
Mr. Douthat's comments recall the editorial advocating "semantic gymnastics" a few posts below this one, as well Helen Alvare's response to my question "is natural law theory just a Catholic Thing?"