Quesnay and the analysis of the surplus in an agrarian capitalist economy

In order to discuss the ‘rational foundation’ of certain aspects of Quesnay´s theory we use a simple formalization of the necessary connections between assumptions about the techniques in use, the distribution of income between the classes and sectors, the system of relative prices. We argue that Quesnay´s system was a truly capitalist agrarian economy and that he was indeed a pioneer of the classical political economy/surplus approach to economics as identified first by Marx, Sraffa and Garegnani, the physical surplus of grains being the necessary basis for his analysis of the distribution and relative prices.