Do supranational institutions matter—do they deserve the status of an independent causal variable—in the politics of the European Community (EC)? Does the Commission of the European Communities matter? Does the European Court of Justice (ECJ) or the European Parliament? Is the EC characterized by continued member state dominance or by a runaway Commission and an activist Court progressively chipping away at this dominance? These are some of the more important questions for our understanding of the EC and of European integration. They have divided the two traditional schools of thought in regional integration, with neofunctionalists generally asserting, and intergovernmentalists generally denying, any important causal role for supranational institutions in the integration process. By and large, however, neither neofunctionalism nor intergovernmentalism has generated testable hypotheses regarding the conditions under which, and the ways in which, supranational institutions exert an independent causal influence on either EC governance or the process of European integration.