Was Mr Say the ultimate nemesis of Lord Keynes?

Profs. Alain Béraud and Guy Numa in this piece says we usually think that Keynes and Say were at opposite ends of each other. However, they are far more proximate than it is imagined:

Since the publication of Keynes’s General Theory of Employment, Interest and Money, generations of economists have been led to believe that Say was Keynes’s ultimate nemesis. By means of textual and contextual analysis, we show that Keynes and Say held similar views on several key issues, such as the possibility of aggregate-demand deficiency, the role of money in the economy, and government intervention.

Our conclusion is that there are enough similarities to call into question the idea that Keynes’s views were antithetical to Say’s. The irony is that Keynes was not aware of these similarities. Our study sheds new light on the interpretation of Keynes’s work and on his criticism of classical political economy. Moreover, it suggests that some policy implications of demand-side and supply-side frameworks overlap.

Finally, the study underlines the importance of a thorough analysis of the primary sources to fully grasp the substance of Say’s message.

In economics we love this comparison of this vs that. But if we analyse closely, there are more similarities than differences.