In this article we shall argue that the Keynesian revolution was a revolution in the sense of Kuhn and that Kuhn's conceptual framework provides a better understanding of the convulsive changes that took place in macro‐economics in the twenties and thirties than alternative growth of knowledge theories that are being discussed in the economics literature at the present time. In the last ten years or so economists have become increasingly interested in the various growth of knowledge theories that have been developed by philosophers of science such as Kuhn, Popper, Lakatos and others. This heightened interest on the part of economists is to be explained by the fact that these new theories are based on the actual behaviour of scientists. The new philosophers of science devote their attention not to “correct scientific method” but to the actual behaviour of scientists. It is because of this revolution in the historiography of science that economists have been able to relate these new theories to their own work and to the development of economic theories in the past.