Slavoj Zizek, author of Violence: Six Sideways Reflections (Picador; July 22, 2008), and Bernard-Henri Levy, author of Left In Dark Times: A Stand Against the New Barbarism (Random House; September 16, 2008) talked about their books on stage with Paul Holdengraber. They debated the parameters of tolerance and the global understanding of human rights. In his book Mr. Zizek examines how violence is perceived and questions whether capitalism and civilization encourage greater violence.