The much debated relations between Rawls and classical utilitarianism are always studied through the kantian face. However, historically, we have to compare Pareto and Rawls so as to understand the rawlsian criticism to utilitarianism. The history of original position stresses the mutual disinterest and not the veil of ignorance. This respect of individual interests is a paretian point. Besides, the rawlsian and paretian critics to Bentham are based on the same arguments. But to build a theory of justice, a sort of common measure is necessary, and this idea is not paretian. The study of the Pareto and Rawls’ relation about classical utilitarianism has to underline this difference and try to explain it. We will suggest the following idea. This sort of common measure is the counterpart of the kantian desire. On the debate about Rawls and utilitarianism, the two notions are in the heart of interpretations.
Paretian welfare economics is generally understood as a mere variant of classical utilitarianism which rests on a specific set of assumptions about the information which is available to decision makers. But it is shown here that a deeper alteration of the meaning of the theory results from these assumptions when they are properly taken into account by means of an implicit but insufficiently recognized principle of “informational validity”. If this principle is duly applied, Paretian prescriptions coincide with liberal judgments and Paretian welfare economics can basically be viewed as a way to give a consequentialist content to deontological liberalism.
This article suggests a new argument for the de-homogenization of Walras’ and Pareto’s contributions, showing that even the common analytical instrument used for the mathematical representation of general equilibrium does not have the same status. Both consider mathematics as relevant in economics, but their epistemological interpretation of it is different, and sometimes even contradictory. The paper shows that mathematics are linked to a form of determinism in Walras, whereas they are a tool to promote individual freedom in Pareto. This opposition is then connected to the opposition between mathematics as a language of nature (in Walras) and mathematics as a tool for science (in Pareto).