A trolley is careering out of control. Up ahead are five workers; on a spur to the right stands a lone individual. You, a bystander, happen to be standing next to a switch that could divert the trolley, which would save the five, but sacrifice the oneÑdo you pull it? Or say youÕre watching from an overpass. The only way to save the workers is to drop a heavy object in the trolleyÕs path. And youÕre standing next to a really fat manÉ.

This ethical conundrumÑbased on British philosopher Philippa FootÕs 1967 thought experimentÑhas inspired decades of lively argument around the world. Now Thomas Cathcart, coauthor of the New York Times bestseller Plato and a Platypus Walk into a Bar, brings his sharp intelligence, quirky humor, and gift for popularizing serious ideas to Òthe trolley problem.Ó Framing the issue as a possible crime that is to be tried in the Court of Public Opinion, Cathcart explores philosophy and ethics, intuition and logic. Along the way he makes connections to the Utilitarianism of Jeremy Bentham, KantÕs limits of reason, St. Thomas AquinasÕs fascinating Principle of Double Effect, and more.

Read with an open mind, this provocative book will challenge your deepest held notions of right and wrong. Would you divert the trolley? Kill one to save five? Would you throw the fat man off the bridge?