Distinguished historian Ferguson and renowned futurist Schwartz disagree profoundly on the nature of human progress. Both use scenarios (called "counterfactual history" by Ferguson) to analyze how events play out. Ferguson wrote "The War of the World" (2006), a history of the violence that defined the 20th Century. Schwartz wrote "The Art of the Long View" (1991), the standard text on scenario planning, and "The Long Boom" (1999), on global prosperity in the 21st century. Both speakers regard history as highly contingent. The question is, contingent on what?"Historian vs. Futurist on Human Progress" was given on April 28, 02008 as part of Long Now's Seminar series. The series was started in 02003 to build a compelling body of ideas about long-term thinking from some of the world's leading thinkers. The Seminars take place in San Francisco and are curated and hosted by Stewart Brand.