Best-selling author and historian Thomas Cahill talks to Bill in a wide-ranging conversation covering everything from the bubonic plague to Christopher Columbus to the nature of human progress.

Bill talks to best-selling author Thomas Cahill about why Pope Francis has conservatives up in arms.

Christ's teaching for his followers to love one another gave way to inter-Christian violence within a few hundred years of his death.

Bill Moyers talks with the author of How the Irish Saved Civilization and revisits an interview with Desmond Tutu.