La combinaison de systèmes de préférences individuelles peut aboutir globalement à choisir une solution qui ne satisfasse personne. C'est à propos des fonctions de préférences collectives existant à un moment donné que Condorcet démontre son célèbre paradoxe. Il semble que son raisonnement puisse être transposé à la formation dans le temps des systèmes de préférences d'un individu. Confronté à des situations changeantes, un individu élabore au cours de son existence des systèmes multiples de préférences, qui rendent la notion même d'individu paradoxale.

At the occasion of the republication of “Mémoires sur les monnaies” (Memoirs concerning Money) of 1790 and of “Discours sur les finances” (Discourse on Finance) of 1792, several apparently contradictory scenarios appear in these texts by Condorcet. They regard the choice of the bi-metallic monetary regime and the inflationary effects of the issuing of paper money during the revolutionary period. What would seem paradoxical from the point of view of a logician becomes much less so when one envisages the man of action, engaged in a combat for justice as much as for truth. If we place Condorcet's argument within its context, we see the true nature of economic reasoning at the moment when it was affirming itself as a scientific discourse. This discourse which belonged to the moral and political sciences is fundamentally normative; it defines itself by a process of trial and error in accordance with the commitments of its author, adapts its argumentation to the evolving circumstances and, what is more, ends up by creating its own truth.