Léon Walras and Vilfredo Pareto on Social Justice

Léon Walras and Vilfredo Pareto on Social Justice The list of the methodological and analytical divergences between Walras and Pareto has been raised by Pareto in a letter he sent to the French economist on 28 April 1896, following the publication in the Revue Socialiste of his article on "Method of conciliation and synthesis" (April 15, 1896). In relation to some questions about Walras' article, Pareto indicates his own position. This one concerns, on the one hand, the method to apply to economics, and on the other hand, his position on social justice From this date, the relations between the two economists don't stop deteriorating until Pareto, in 1901, refused to admit the results contained in the marginal productivities theorem proposed by Walras in the last edition of his Éléments d'économie pure. Walras considered that theorem "as an essential result for economics" because it would permit to build a connection between pure economics and social justice. In others words, according to Walras, the marginal productivities theorem constitutes an exemplary illustration of connection between pure economics, object of truth, of applied economics, object of utility, and of social economics, object of justice. According to Pareto, pure and applied science cannot be sufficient to explain social facts because of complexity whereas for Walras pure economics contains answers about questions of social justice. In contrast Pareto separated the relative fields of pure economics and of applied economics and considered that social economics doesn't constitute a scientific discipline. Moreover the distinction between pure and applied science was a keystone of Paretian epistemology right from the beginning of his career and in Pareto's approach pure science is analytic and applied science is synthetic. In this paper we shall be mainly concerned by the reasons which depend on the disagreement between Walras and Pareto on social economics. In section I we will reconsider the question of marginal productivities theorem as a solution of social justice. Section II should be devoted Pareto's conception of justice and we would integrate the theory of actions as it stands out from the Treatise on General Sociology with the concept of derivations. So we would tempt to explain then why Paretian methodology implies to make that economics is depending of the sociology laws, beyond the fact that the author claims to proceed by successive approximations. In section III, we would show how Walras' and Pareto's opposite positions on social justice do not constitute a special case but are part of their views on epistemological conceptions of individual and of social science. Section IV will conclude.