The philosopher Saint Augustine of Hippo is one of the most important figures in the history of Christianity. His efforts against the Manichean, Arian and Pelagain heresies shaped the fundamentals of Christian doctrine. His Confessions tells the story of his own conversion from Manicheanism to Christianity. His philosophical ideas anticipated Saint Thomas Aquinas and Descartes. His three-volume City of God remains a classic of Christian apologetics. And many find the roots of some of the darker sides of Christian doctrine, from the emphasis on original sin to the second-rate status for women, in his works. John and Ken welcome Georgetown University Provost James O'Donnell, author of Augustine, Sinner & Saint: A New Biography.