This essay developed out of my contribution "Das Recht im Prozess der Europaischen Integration" to Markus Jachtenfuchs/Beate Kohler-Koch (eds.), Europaische Integration, Opladen: Leske + Budrich, 1996, 73-108 [in English: Taking the Law Seriously: On Political Science and the Role of Law in the Process of European Integration, 2 (1996) European Law Journal, 105-135]. Since the paper seeks to address political scientists, some of its sections, especially those on the history of Europe's 'juridification', may encounter deja vu reactions from lawyers. But this should not be true for the approach as a whole. "Constitutionalisation" comprises in my understanding, both individual liberties and the rights of citizens to political participation. This is why the impact of Europeanisation and globalisation on the configuration of the economic system, the institutionalization of the welfare state and labour market are of "constitutional" importance. They affect profoundly the balance of private autonomy and political rights. I have little hope that the so-called "Convention Method" will provide us with more than partial response to these challenges which Europe faces in the process of its constitutionalisation. Nor should the Charter of Fundamental Rights be expected to resolve these issues.