What characterizes the EU today is that it is not only a multi-level governance system, but also a multi-context system. The making of Europe does not just take place on different levels within the European political framework, executed by different groups of actors or institutions. Rather, it also happens in different and distinguishable social contexts – distinct functional, historical, and local frameworks of reasoning and action – that political science alone cannot sufficiently analyze with conventional and generalizing models of explanation. The European law is such a context, and it should be perceived as a self-contained sphere of argument and action that generates impetus for integration. Therefore, the role of the European Court of Justice in the process of integration may only be adequately captured by examining European law as an independent space of reasoning and action. key words: European Court of Justice (ECJ); Integration through Law; Integration Theory; Regional Integration; Rationalism; Trivial Rationalism; Context Rationality; Context of Law; Context Analysis; Judicial Politics. *Andreas Grimmel is a Ph.D. student and works as a lecturer at the University of Hamburg and the Europa-Kolleg Hamburg. He is also scientific consultant and managing director of the Gemeinschaft fur Politikberatung (Association for Political Advice, www.gpb-hamburg.de). This paper was written in 2010 during a research stay at the Department of POLIS (Department of Politics and International Studies) at the University of Cambridge, UK. The author thanks Dr. Arif Ahmed, Prof. Catherine Barnard, Prof. Bengt Beutler, Prof. Thomas Bruha, Prof. Alan Dashwood, Dr. Markus Gehring, Dr. Geoffrey Edwards, Prof. Armin Hatje, Prof. Jane Heal, Prof. Christopher Hill, Prof. Cord Jakobeit, and Dr. Julie Smith for their advice, guidance, and many helpful comments on this research.