Os Guinness (DPhil, Oxford) is the author or editor of more than thirty-five books, including The Dust of Death, The Call, Fool's Talk, Carpe Diem Redeemed, The Magna Carta of Humanity, Last Call for Liberty, Impossible People, Unspeakable, and Time for Truth. He is the founder of the Trinity Forum, a prominent social critic, and a frequent speaker who has addressed audiences worldwide.