Througout his life Hayek had a profound interest in money and its role within the economy. Money plays a critical part in his 1920s work on the trade cycle, which attempts to integrate capital theory and monetary theory. As late as the 1970s, Hayek was advocating radical reform of the monetary system, suggesting that the supply of money be turned over to private enterprise. This volume, together with Volume Six, Good Money, Part Two, collect all of Hayek's significant writings on money. Together they amply demonstrate both the significance of 'sound money' in Hayek's economic vision, and Hayek's importance as a monetary theorist.