Arthur Seldon was one of the most influential economists of the late twentieth century. His ideas were key to the changes in economic policies under Margaret Thatcher's government and which spread to many other countries. Seldon was for thirty years the editorial director of the Institute of Economic Affairs, where he directed a publishing programme which included some of the world's most eminent economists, such as Milton Friedman and Friedrich Hayek, advocating, among other things, less government intervention, control of inflation by monetary means, and reduced power for trades unions. Seldon was also a prolific author, and his Collected Works occupy seven volumes. This new biography concentrates on Seldon's intellectual contribution and traces the roots of his work from his childhood in the Jewish East End of London, where self-help and voluntary aid for the disadvantaged were the norm, through his time at the London School of Economics, where he was influenced by some of the leading economists of the 1930s, to his time at the IEA, where he worked in partnership with Ralph Harris.