This publication comprises a reappraisal of the work of John Maynard Keynes. It strengthens the view that the Keynesians went too far in supposing that the old economics had been overthrown by the new, and in a sense it rehabilitates both classical economics in a modern form and also Keynes as a theorist who added an important development to it, although the 'Keynesian Revolution' began and stayed on the wrong track partly because of Keynes's polemical presentation. Issues discussed include the multiplier; unemployment and effective demand; the saving-investment problem; and fiscal policy.