This conclusion presents some closing thoughts on the key concepts discussed in the preceding chapters of this book. The book argues that historical institutionalism or path dependency does not provide a sufficient explanation for the development of the European Union. Institutions need to be infused with a continuing supply of ideas and norms. Many more case studies of the evolution of the European Union will be required to determine the extent to which the ideas of the founders have influenced the later development of the European Community. The European Community is an institution created in response to the European norm. So this creation in itself strengthened the support for the European idea. The relationship between the actual process of European integration and the supposed end-product of a federal European state is an ambiguous one. The most recent attempts to write a European constitution are an illustration of this line of thinking.