Rex Features via AP Images) F or years, the solemn benediction given by the Pontiff of the Catholic Church to the City of Rome and the world on Christmas Day has been urbi et orbi , a blessing that conveys nothing less serious than the full absolution of his flock’s sins. (The phrase translates literally as: “to the city and to the world.”) But when thousands of faithful Catholics gather on St. Peter's Square in Rome this Christmas, the current head of their church, Pope Francis, might be just as likely to wish them—along with the hundreds of millions tuning in via radio, TV, and the internet—a very down-to-earth buon pranzo , which literally means “enjoy your lunch.” Francis has issued this unconventional greeting on previous occasions, eliciting horror from Vatican officials of all ranks. It’s just one of the many ways that Pope Francis has broken ranks with the conservative wing of the Catholic Church, especially on issues that involve the church‘s moral teachings, like divorce and...