Stefano Solari

The notion of ‘social justice’ emerged in political economy debates in the XIX century. This concept was developed particularly by Walras and by Catholic social economists. While Walras found inspiration in the view of natural law expressed by Quesnay, Catholic economists based their reflections on the Neo-Thomistic (or New Scholastic) philosophical thought developed by the Jesuits. We first study the main differences in the use of this concept among economists in the second half of the XIX century. Second, we analyse the connection between the notion of social justice and the ‘classical’ natural law from which it was derived. Then we highlight the debate which developed around this concept between the main currents of Roman Catholic social economics and the official adoption in encyclicals Quadragesimo Anno and Divini Redemptoris. This essay concludes by examining the impact that differing definitions of rights and the law have had on economic theory. Key words: Social justice, Thomism, Classic natural law, Quesnay, Walras. JEL Classification: B49, P48, Z12.