The emergence of political economy as an autonomous field of study is normally linked to the publication of Adam Smith’s An Inquiry into the Nature and Causes of the Wealth of Nations, in (1776). Physiocracy is a branch of economic thought that comes before the development of political economy: it is, in all respects, the forerunner of classical political economy. The most influential author of this school is François Quesnay (1694–1774). He was a surgeon linked to the French Royal Court. However, he was also very interested in economic issues. He conceived a representation of the flows of commodities among the various sectors of a stationary economic system, which became immediately famous and known as the Tableau economique. The Tableau economique provides a graphical representation of these transactions. The production process occurs within a finite period of time called the ‘year’.