In the wake of his enormously popular books The Armchair Economist and More Sex Is Safer Sex, Slate columnist and economics professor Steven Landsburg employs concepts from mathematics, economics, and physics in this sprightly tour of the deepest problems in philosophy: What is real? What can we know? Why is there something instead of nothing? And how should we live? Beginning with the broadest philosophical issues--theories of existence, knowledge, and ethics--Landsburg then turns to a dazzling variety of specific applications. He gives us a mathematical analysis for arguments for the existence of God; explains the real meanings of the Heisenberg uncertainty principle and Gödel's incompleteness theorem; and carefully dissects the meaning of social responsibility on the playground, in the marketplace, and in the voting booth. Stimulating, illuminating, and always surprising, The Big Questions reveals the relationship between the loftiest philosophical quests and our everyday lives.