European integration has been both a political and a legal process. During the 1990s, interdisciplinary research proposed new theories of ‘judicialisation’ that sought to capture this relationship between politics and law. Yet As Julien Bois and Mark Dawson write, political scientists and legal scholars now appear to be increasingly divided in their accounts of judicialisation within the EU.

Integration-through-law has long been described as the means through which the EU became a fully-fledged polity. The importance in this process of the Court of Justice of the European Union is central. This speaks not only to the canonic doctrines that emerged from its early cases in the 1960s and 1970s, but the Court’s cooperation with other bodies such as the European Commission and national courts. As an actor sitting between law and politics, the Court has thus been historically important in breaching disciplinary divides (that often lead lawyers and political scientists to study European integration in silos).

In the 1990s, scholarly pioneers such as Joseph Weiler, Anne-Marie Slaughter, Christian Joerges, Karen Alter and Alec Stone Sweet developed a more comprehensive framework of integration by combining insights from law and political science. The publication in 1998 of the book The European Court and National Courts – Doctrine & Jurisprudence: Legal Change in its Social Context was the clearest illustration of an interdisciplinary alliance between political scientists and lawyers to forge new judicialisation theories.

While the scope for interdisciplinary research seemed high at the dawn of the 20th century, renewed interest in the EU courts also established an alternative (and more concerning) path. Since the early pioneers were able to translate their findings regarding judicialisation into their own conceptual language – such as judicial empowerment for political science or judicial dialogue for legal scholarship – they also planted the seeds of an alternative future: academic and disciplinary autopoiesis.

By raising the profile of judicialisation research within each discipline, they also rendered it less necessary for lawyers and political scientists to reach across disciplines, allowing findings on judicialisation to be ‘re-translated’ into the well-established ontological and epistemological canons of each discipline. These two paths raise an important empirical question: has interdisciplinarity about the Court of Justice of the European Union increased, decreased or remained the same in EU studies during the last 20 years?

Assessing the literature

In a recent study, we used a mixed-methods approach to answer this question. First, we conducted a scientometric literature review of the articles of two major European Studies journals: the Journal of Common Market Studies and the Journal of European Public Policy. The purpose was to determine whether authors publishing in leading political science journals would increasingly quote legal scholarly literature or not.

Choosing several cutoff points to assess the trend over the last 25 years, we found no discernible pattern among the 3,084 references analysed (throughout 72 articles). The analysis showed that quoting literature from legal scholarship was very contingent upon specific authors, and that there was no clear pattern over time. References to legal scholars irregularly ranged from 15 to 32%, showing neither increases nor decreases over time.

Since the quantitative cross-time series could not uphold or discard our hypotheses, we applied a qualitative approach by analysing in depth three publications that dealt with three recent socio-economic issues: the eurozone debt crisis, the applicability of UN resolutions restricting fundamental rights, and the ‘citizenship turn’ regarding residence rights. Our hypothesis in selecting these pieces was that these contexts simultaneously raised legal and political issues, i.e. displayed doubts regarding the interpretation of the treaties as well as legitimacy concerns regarding the EU’s role as a policy leader in solving these issues.

Our qualitative findings also display differences as well as a common deficiency – the struggle of political science work on the Court to properly integrate into its approach the unique norms and features of legal institutions. In the first paper we assessed, by Nicole Scicluna, we found a comprehensive approach combining legal interpretations of Economic and Monetary Union provisions with difficulties caused by the socio-economic turmoil of the early 2010s.

This is used to provide an interpretation of the paradigm shift in EU economic governance allowing the mutualisation of joint debt. The inter-disciplinary quality of this paper lay in its ability to connect the difficulties associated with the interpretation of the no-bailout clause to the widely shared drive of major political leaders to overcome this constitutional difficulty. The article therefore provides a plausible explanation of judicialisation by embedding socio-political factors in legal discussions over how to interpret the Treaty’s economic policy chapter.

On the other hand, the second paper we examined, by Michael F. Harsch and Vladislav Maksimov, and the third paper, by Michael Blauberger et al., both sought support for their theses about judicial behaviour by exclusively focusing on actors’ strategies and socio-economic changes. While their respective articles provide evidence for a correlation between public opinion and media coverage on the one hand and judicial behaviour on the other, the authors cannot exclude that doubts surrounding the interpretation of the legal framework had a significant impact on changes in the Court of Justice of the European Union’s approach.

Therefore, the interpretations provided in these two papers are socially, but not legally, plausible. We argue that this shortcoming results from the gradual consolidation of strong, cognitive, disciplinary barriers in the 21st century. Political science work on judicialisation has begun to lose a capacity that earlier pioneers carried – the ability, as Christian Joerges once put it, to ‘take the law seriously’.

How can these shortcomings be overcome?

This question seems particularly timely considering the stakes raised by the cases discussed above, which are now also accompanied by new challenges in fields such as digitalisation and public health. A first tentative answer is to engage with arguments developed in political science and legal scholarship.

The epistemological divide according to which legal academia mostly seeks to provide normative arguments whereas political science aims to unpack empirical (and often causal) mechanisms is not absolute. Normative arguments give rise to empirical claims, and empirical analyses can be reappropriated in debates regarding the desirability of legal change. Therefore, arguments developed by lawyers and empirical social scientists can be combined in a comprehensive study, at least in the theoretical section.

For political scientists, this means testing hypotheses arising out of legal scholarship, something that was originally done by the pioneers mentioned above (and which was recently applied by Tommaso Pavone in an assessment of the famous ‘judicial empowerment’ thesis in a recent monograph). For lawyers, this means accepting the actorness of the Court of Justice of the European Union as a political player whose actions reflect both legal reasoning and contextual pressures.

A second tentative answer is to provide a theoretical account that is tailor-made to judicial politics in the EU. Theoretical comparisons drawn from judicial politics in another polity (especially the US) and transnational politics must account for the specific nature of the Court of Justice of the European Union as a judicial body.

The Court of Justice of the European Union is simply not able to interpret the law as it pleases as it must deal with cases that arrive to Luxembourg according to the specific institutional features of the EU (meaning the Court cannot choose its cases and must also decide cases with a view to resolving the dispute of the specific parties before it).

At the methodological level, this implies looking more closely at the activities of judges themselves, rather than drawing hasty conclusions derived from social action theories applied in other contexts. In other words, ‘taking the law seriously’ while not solely focusing on it should provide an intermediary path for judicialisation theories plausible to lawyers and political scientists alike. We hope our work provides a basis for looking again at the study of judicialisation in the EU.

For more information, see the authors’ accompanying paper at the Journal of European Integration

Note: This article gives the views of the authors, not the position of EUROPP – European Politics and Policy or the London School of Economics. Featured image credit: Court of Justice of the European Union