Paul A. Samuelson is widely regarded as the world's leading economist in the so-called “Age of Keynes”, the three decades after WWII, acknowledged by his being the first American to win the Nobel prize in economics. Foundations of Economic Analysis was a manual on how economic theory should be done, and the nineteen editions of Economics: An Introductory Analysis provided the first exposure to economics for millions of students worldwide. Volume I of this intellectual biography told the story of someone who established himself as the most promising economist of his generation. This volume shows how he went on to dominate the subject. He was well known as a mathematical economist at a time when the use of mathematics in economics was in its infancy but, as this volume shows, he was far more than that. He wrote seminal articles in field after field, including consumer behaviour, international trade, consumer, finance, public expenditure, optimal taxation, the economics of inflation and