Right-wing Catholic intellectuals like to claim that the Vatican's absolute opposition to abortion (and homosexuality, and contraception) is grounded in something called "natural law," a body of moral principles that are accessible to all human beings through both reason and conscience. Because these principles can be known by all of us, regardless of our theological convictions, they are supposed to be binding on all of us.

Here, for example, is a recent (and representative) statement by theocon George Weigel:

[T]he Church’s opposition to the taking of innocent human life, at any stage of the human journey, is not some weird Catholic hocus-pocus; it’s a first principle of justice than can be known by reason. It is a “requirement of the natural moral law” — that is, the moral truths we can know by thinking about what is right and what is wrong — to defend the inviolability of innocent human life. You don’t have to believe in papal primacy to know that; you don’t have do believe in seven sacraments, or the episcopal structure of the Church, or the divinity of Christ, to know that. You don’t even have to believe in God to know that. You only have to be a morally serious human being, willing to work through a moral argument — which, of course, means being the kind of person who understands that moral truth cannot be reduced to questions of feminist political correctness or partisan political advantage.

As this passage makes clear, the theocons believe that "all morally serious human being[s]" agree with them -- aside, of course, from those who are deluded by feminist ideology or blind partisanship. (Weigel places into these latter categories Nancy Pelosi, Joe Biden, Ted Kennedy, John Kerry, Barbara Mikulski, Rose DeLauro, Kathleen Sebelius, and pretty much every other Catholic Democrat in Washington.) And this conviction about the self-evident truth and universality of natural law theory leads the theocons to propose using it as a foundation for moral consensus in the United States.

There's just one problem with the proposal: "natural law," as both the theocons and the Catholic Church employ the term, is a fraud.

Think I'm being tendentious? Allow me to present Exhibit A:

It seems a nine-year-old, eighty-pound girl in (heavily Catholic and staunchly pro-life) Brazil was raped by her stepfather and became pregnant with twins. She was given an abortion on the grounds that she would not have survived the pregnancy. This inspired the local archbishop, Jos