Former Colorado Senator and two-time presidential contender Gary Hart describes what he calls “the increasing gap between purpose and performance” in America in his book, The Republic of Conscience. Director Matthew Heineman talks about his new film, “Cartel Land,” an on-the-ground look at the journeys of two modern-day vigilante groups and their shared enemy - the murderous Mexican drug cartels. Military analyst P.W. Singer and national security analyst August Cole look at what the next global conflict may be in their futuristic thriller, Ghost Fleet. The Economist’s “Schumpeter” columnist, Adrian Wooldridge, compiled a book of his columns addressing the causes and consequences of the unprecedented disruption of business over the past five years.