The Vatican made headlines this month with its release of Dignitatis Personae (Latin for "The Dignity of the Person"), which updated Catholic teachings on bioethics and reaffirmed opposition to the cloning, killing and manipulating of human embryos. Critics have blasted the document as proof of the church's inexplicable fixation on embryos. They ask: Why devote such energy to defending the rights of a microscopic dot? Why throw up roadblocks to the Brave New World of biotech advances — including the detection and destruction of genetically flawed embryos in pursuit of so-called designer babies — to save infinitesimal entities no one...