The public mea culpa has become akin to performance art in modern times. It seems a month seldom goes by without a celebrity, public figure or politician begging for forgiveness via the mass media. Repentance and forgiveness have not always been such public, interpersonal matters, however. In the days before the Protestant Reformation, forgiveness was up to God and God alone. In her new book, "Shakespeare and the Grammar of Forgiveness" (Cornell University Press/2011), Duke University English Professor Sarah Beckwith traces the roots of our modern understanding of forgiveness to the language of William Shakespeare's later plays. Host Frank Stasio talks with Beckwith about how we say "I'm sorry."