Irving Fisher was one of America's greatest mathematical economists - and certainly one of the most colourful. During his career, he made numerous contributions to mathematical economics, capital theory, monetary theory, and statistics. The now familiar distinction between stocks and flows is almost entirely due to Fisher's The Nature of Capital and Income, and similarly, his theory of money and prices is the foundation of much contemporary monetary economics. An influential and controversial figure during his lifetime, Fisher's work remains accessible and useful to students of economics today. This impressive collection brings together key contemporary responses to Fisher's work, along with later assessments of his main contributions. Also including a new introduction to the collection and individual volume introductions by the editor, this unique set is undoubtedly a valuable research resource for both student and scholar.