Is causation a fundamental principle that orders the universe, or a construct invented by human beings? What does it mean to exist? In this provocative audio series, Dr. Robert Lawrence Kuhn, creator and host of the hit PBS series Closer to Truth, probes causality, existence, and other heady philosophical topics in intimate conversations with thirteen of the world's greatest thinkers. Among Kuhn's interlocutors are Alvin Plantinga, the John A. O'Brien...