Robert Heilbroner's history of economic thought has introduced generations of readers to the ideas that shape how we understand capitalism. He profiles the 'worldly philosophers'—Adam Smith, Thomas Malthus, David Ricardo, Karl Marx, John Maynard Keynes, and others—explaining their theories while placing them in historical context. Heilbroner was a gifted writer who made complex ideas accessible without oversimplifying. He conveys the intellectual excitement of thinkers who were trying to understand a new kind of society, one organized around markets rather than tradition or command. The book traces how each theorist built on or reacted against predecessors, creating a cumulative tradition while leaving deep disagreements unresolved. First published in 1953 and revised multiple times, the book reflects Heilbroner's own evolving views about capitalism's prospects and problems. For readers seeking to understand the intellectual foundations of economic policy debates, or simply curious about the ideas behind headlines about markets and growth, this remains the essential introduction.