The argument of this paper is that Jacques Rueff and F.A. Hayek can be made to have a constructive dialogue that informs our understanding of how both authors approached such issues as the role of government in society and the meaning of spontaneous order. Through an analysis of their uses of the price mechanism as an ordering principle, and an examination of how they both moved towards a legal-institutional approach to understand the world, the common elements in their systems are brought out and fitted in a longer liberal tradition concerned not only with the meaning of competition, but with the conditions fostering the emergence of social order in the midst of individual chaos. Rueff’s involvement in the construction of the European Coal and Steel Community gives an interesting application of their systems to a concrete experiment in creating a rational economic order in postwar Europe. The examination of the case law of the Court of Justice of the Community demonstrates how much the principle of competition was subordinate to a political ideal of peace relying on limiting governments to prevent wars, a mechanism at the center of both Hayek’s and Rueff’s systems.