In analyzing money, contemporary economics has focused its attention on money's function as a store of value, neglecting its role as medium of circulation. When circulation is put center stage, it becomes apparent that the supply of money does indeed adapt to the needs of trade - and does so in many different ways, often ways that are difficult for a central bank to control, because they reflect the responses of banks and other financial institutions to market incentives. But money's role in circulation must be coordinated with its store of value function, and both with finance. Failure here can lead to instability. The essays in this volume by internationally renowned economists cover these issues in original and contrasting analyses, presenting the American post-Keynesian perspective, on the one hand, and the point of view of the French Circulation School, on the other.