The great economists were harbingers of new ideas. The economic policies they recommended were at variance with the policies practiced by contemporary governments and political parties. As a rule many years, even decades, passed before public opinion accepted the new ideas as propagated by the economists, and before the required corresponding changes in policies were effected.It was different with the "new economics" of Lord Keynes.
The policies he advocated were precisely those which almost all governments, including the British, had already adopted many years before his "General Theory" was published. Keynes was not an innovator and champion of new methods of managing economic affairs. His contribution consisted rather in providing an apparent justification for the policies which were popular with those in power in spite of the fact that all economists viewed them as disastrous. His achievement was a rationalization of the policies already practiced. He was not a "revolutionary," as some of his adepts called him. The "Keynesian revolution" took place long before Keynes approved of it and fabricated a pseudo-scientific justification for it.
What he really did was to write an apology for the prevailing policies of governments.This explains the quick success of his book. It was greeted enthusiastically by the governments and the ruling political parties. Especially enraptured were a new type of intellectual, the "government economists." They had had a bad conscience. They were aware of the fact that they were carrying out policies which all economists condemned as contrary to purpose and disastrous. Now they felt relieved. The "new economics" reestablished their moral equilibrium. Today they are no longer ashamed of being the handymen of bad policies. They glorify themselves. They are the prophets of the new creed.