Karl Marx Found a Marvellous Weapon in Ricardian Economics, Which Ignores Market Exchanges by Focusing Instead on Production Followed by Distribution of Income

As Karl Marx plunged into the economics of capitalism that would occupy the rest of his life, he found ready at hand a marvellous weapon: Ricardian economics. In contrast to J.B. Say and the French tradition, Ricardo concentrated not on market exchange and its inevitable focus on individual actors and exchangers benefiting from exchange, but on 'production' followed by 'distribution' of income as a distinct and separate process. Ricardo's main focus was on how this social income from production is 'distributed'. Whereas Say or Turgot looked at individual factors of production and how their income emerges from production and exchange, Ricardo focused only on entire, allegedly homogeneous, 'classes' of producers: workers earning wages, capitalists earning 'profits' and landlords acquiring rent.

--Murray N. Rothbard, Classical Economics, vol. 2 of An Austrian Perspective on the History of Economic Thought (Auburn, AL: Ludwig von Mises Institute, 2006), 392.