John Cotter, Lecturer in Law, School of Law, Keele University

A common saying, often credited to Benjamin Franklin, states that only death and taxes are inevitable. If we interpret “certainty” literally, legal professionals trying to anticipate the results of a case might concur. Predicting court outcomes involves significant challenges. Some stem from ambiguity within legal rules themselves, stemming from the limits of language in conveying meaning (“legal obstacles”). Others arise from external factors that influence how rules are selected, interpreted, and applied to a case (“extra-legal obstacles”). These can include the personal biases of those working with the law, the complexities of fact-finding, institutional influences on decision-makers, or case-specific elements like the competence of legal representation.

These hurdles are arguably even more substantial in EU law. Translated into twenty-four official languages of equal weight, EU laws often reflect considerable compromise among governments and institutions. The EU’s intricate structure, more complex than many national legal and political systems, may expose the Court of Justice to a wider array of competing, and potentially less transparent, external pressures. Such obstacles pose a concern for a legal system like the EU’s, which aims to ensure its laws are applied consistently and effectively across its diverse member states. Legal certainty is a fundamental principle of EU law, and the Court of Justice emphasizes that EU laws must be unambiguous and predictable for those subject to them (Cases 212-17/80 Meridionale Industria Salumi and Others).

Since Court of Justice rulings effectively shape EU law, this statement holds weight for the Court itself. Clarity and predictability are particularly crucial in the context of the Article 267 TFEU preliminary reference procedure. Through this process, the Court addresses questions from national courts about the validity or interpretation of EU law, issuing rulings binding not only on the referring court but also on courts across all EU member states. This procedure has been instrumental in fostering a consistent and effective interpretation of EU law throughout the Union.

However, acknowledging these obstacles doesn’t imply a level of uncertainty where outcomes are completely arbitrary. My book aims to highlight factors within the EU legal system, particularly the preliminary reference procedure, that mitigate these obstacles. Drawing from American legal realist Karl Llewellyn’s work, The Common Law Tradition: Deciding Appeals (Little Brown 1960), I refer to these mitigating factors as “steadying factors.” Llewellyn, countering the notion that US appellate court decisions were unpredictable, proposed fourteen steadying factors that contributed to reasonably predictable decisions.

Chapter 2 identifies the steadying factors from Llewellyn’s work that apply to the Court of Justice, categorizing them as either legal or extra-legal. While “legal doctrine” and “known doctrinal techniques” are recognized as legal steadying factors, my book focuses on extra-legal factors—those beyond specific legal rules, principles, or interpretation methods. I argue that these contribute to more stable preliminary reference outcomes by: (1) reinforcing the influence of legal rules on judges, (2) narrowing down potential outcomes, and (3) providing guidance for legal professionals attempting to predict outcomes. These extra-legal steadying factors are further classified as internal, external, and procedural.

Part II of the book (chapters 4 and 5) explores internal factors, which encompass the shared values, perspectives, and practices that judges internalize. Building on Llewellyn’s concept of “law conditioning” through legal education and professional experience, I assume this leads to a shared understanding of legal rules and a more standardized approach to interpretation. Chapter 4 redefines Llewellyn’s “law-conditioned official,” applying this revised definition in chapter 5 to the backgrounds of past and present Court of Justice judges. The analysis reveals that since 1952, 100 out of 111 judges had twenty or more years of legal experience post-qualification. It also highlights a tendency for judges to possess expertise in European law or international legal experience prior to their appointment, potentially minimizing the impact of diverse legal backgrounds on their approach to interpretation.

Part III delves into external factors—elements that mitigate the influence of external pressures on judges and reinforce the constraints of legal rules. Chapters 6-10 test a hypothesis, stemming from Llewellyn’s “judicial security and honesty” steadying factor, that the institutional framework of the EU legal system and the Court of Justice’s relationship with other institutions promote stability in preliminary reference outcomes. This two-part hypothesis proposes that: (1) institutional independence allows the Court and its judges to issue rulings against the interests of powerful entities, while (2) accountability mechanisms make it more likely they’ll face consequences if rulings deviate significantly from established legal doctrine.

Part IV (chapters 11-15) examines procedural factors—aspects of the preliminary reference procedure, influenced by rules and practices, that narrow the Court’s decision-making options. Six of Llewellyn’s factors are applied to the preliminary ruling procedure in their typical chronological order: “issues limited, sharpened, and phrased in advance,” “a frozen record from below,” “adversary argument by counsel,” “a known bench,” “group decision,” and “an opinion of the court.” This analysis emphasizes how these factors limit the Court of Justice’s discretion or shape its approach. For instance, the importance of Article 267 TFEU in preventing the Court of Justice from determining facts in the main proceedings and restricting it to ruling on specific EU law questions is discussed.

Additionally, other procedural elements that curtail the Court’s ability to pursue agendas lacking a legal basis are considered. For example, the division of labor means the Court of Justice relies on national courts for referrals, cannot initiate them, and lacks control over its caseload. Furthermore, the influence of the referring court’s questions on the scope of the Court’s inquiry is analyzed. Attention is also given to the Court’s deliberation and decision-making processes, noting that judgments are always collective decisions, requiring justification in written rulings. These aspects minimize the impact of individual biases and compel judges to demonstrate the soundness of the Court’s reasoning.

The book concludes that these steadying factors promote consistency and predictability in preliminary rulings by, among other things, compelling the Court to operate within the boundaries of legal doctrine and accepted interpretation methods. This pressure arises from a combination of internalized judicial values, external accountability, and procedural constraints on judges’ discretion. While acknowledging that predicting Court of Justice rulings with absolute certainty remains impossible, the book contends that these factors help reduce uncertainty and ensure the Court considers the impact of its interpretations and applications of the law.