This book demonstrates the relevance of the historical perspective with respect to national and international payment systems. Its analysis of national and international payments develops along a dialectical path that starts with the work of the Classics (thesis), undergoes a radical turn with the advent of the neoclassical school (antithesis), and reaches the modern theory of emissions passing through Keynes's contribution (synthesis). That the history of economic thought occupies a legitimate place in the field of historical studies is beyond dispute. What may be less well understood is that it can serve purposes beyond those of the academic community of historians. This book critically investigates the contributions of the greatest economists of the past to provide insights into the pathologies of today's systems of national and international payments and into the reforms that are needed to correct them. It will be relevant to students and researchers interested in economicpolicy and the history of economic thought.