Alcide De Gasperi and Konrad Adenauer, two founding fathers of European integration, shared a bilingual culture, a strong Catholic faith, and a market-oriented economic approach based on the prin- ciple of subsidiarity. We analyse the reflections on European eco- nomic integration by the Italian values-grounded liberals Luigi Sturzo and Luigi Einaudi and by the German social market economists Al- fred Müller-Armack and Wilhelm Röpke, all of whom influenced the policies of De Gasperi and Adenauer and their contributions to the Treaty of Rome. The conclusion draws lessons for the present and future state of the European Union.