This pamphlet studies the debate between John Maynard Keynes and the Treasury from 1919-1946, and discusses the implications of recent research. The traditional picture of Keynes as a Cassandra with the right solutions to unemployment and inflation has been challenged both by new documentary evidence and by economic historians using quantitative methods. Problems in the managed economy since the 1970's have also cast an undeserved shadow on Keynes's reputation. His ideas, and those of the Treasury, can now be looked at in historical perspective.