The great stimulus to macroeconomic theory provided by Keynes is well recognised, but much less is said about his views on scientific methodology and his influence there. There is a widespread belief among economists that Keynes was an a priori thinker who dealt with “facts” and empirical material in a cavalier and high‐handed manner. We question the validity of this interpretation and give evidence to show that Keynes' methodology was not hostile to empiricism.