The Emergence of Constitutionally Conforming Interpretation

3.1 The Original Version of Constitutionally Conforming Interpretation: Introducing the ‘Presumption of Constitutionality’

The external conditions conducive to the emergence of constitutionally conforming interpretation were first present in the United States, which is why this tenet was impactful there nearly a century before it was introduced in Europe. The principle of interpreting statutes ‘in harmony with the Constitution’ is one of the earliest to be found in New World legal methodology.^[26] Institutionalized in a ‘presumption of constitutionality’ (of legislation), it evolved into what would later be referred to as ‘the postulate of constitutional adjudication’.^[27] This postulate constitutes the earliest version of constitutionally conforming interpretation to be found on the market. Before retracing its development in more detail, let me briefly elaborate on its conceptual foundations.

While this presumption has been articulated in various ways in Supreme Court case law over the centuries,^[28] it is perhaps best conveyed through the following rule which has circulated since the 18th century: ‘Where the validity of a statute is assailed and there are two possible interpretations, by one of which the statute would be unconstitutional and by the other of which it would be valid, a court should adopt the construction that will uphold it, even though the construction that is adopted does not appear to be as natural as the other’.^[29] Although the scope and boundaries of this presumption do not seem to be uniformly defined,^[30] its application and functional demarcation are, in principle,^[31] uncontested. As commonly described, the presumption serves as a selection rule, necessitating that potential interpretations of the relevant statute have already been construed. If there is no doubt regarding the constitutionality or unconstitutionality of the statute in this technical sense, the presumption finds no application.^[32]

This initial ‘American model’ of constitutionally conforming interpretation, defined as the presumption of constitutionality, is notably characterized by its strong procedural focus.^[33] In line with the common law tradition,^[34] it serves also as an evidentiary presumption, thereby extending beyond a regular tenet of interpretation.^[35] Like other evidentiary presumptions, the presumption of constitutionality places a burden of proof on a party alleging that a statute is unconstitutional. Outside the courtroom, the presumption of constitutionality is applied like a regular interpretative tool for determining a statute’s meaning, alongside many other canons.^[36] However, within the courtroom, it falls to the challenging party – not the judge – to disprove its applicability: ‘To put it paradoxically, the presumption is conclusive unless the party challenging the statute demonstrates that it contravenes the State or Federal Constitution’.^[37]

Owing to its intrinsic procedural law aspect, constitutionally conforming interpretation in this spelling is accepted to function differently across different areas of law. In line with American legal methodology and evidence law more generally, particularly the Supreme Court’s case law concerning the level of scrutiny applicable when evaluating constitutional challenges,^[38] the presumption of constitutionality and the burden of proof it places on parties vary in strength depending on the specific context.^[39] For example, the presumption weights stronger for tax law statutes or other legislation deemed to be of particular public interest, meaning that the party claiming for such a statute to be unconstitutional is required to bring forward substantially stronger arguments in favor of their proposition as they would normally have to. American doctrine underpins this mostly by separation of powers concerns: statutes representing ‘peculiar[] legislative function[s], involving political give-and-take and awareness of local conditions’ require courts to take an especially deferential stance in judicial review.^[40] In contrast, there are legal domains in which the presumption of constitutionality is held to be less substantial, thus easing the burden of proof for those seeking the courts’ protection. For statutes interfering with the safeguards enshrined in the bill of rights, the presumption may even reverse to its opposite, as has most notably been held in some first amendment cases.^[41] For example, ‘any system of prior restraints of expression comes before the court bear[s] a heavy presumption against its constitutional validity’.^[42]

Another distinctive feature of the early American model of constitutionally conforming interpretation is that it is not typically treated as an autonomous tenet of statutory interpretation. Instead, it was soon acknowledged as part of a broader interpretive principle. Frequently, the presumption of constitutionality is considered a component of a more general ‘presumption of validity,’ which applies not only to statutes and state actions but also to other forms of legal texts.^[43] For instance, a will, contract, or other private law document should, in case of doubt, be interpreted in a manner that does not render its provisions unlawful.^[44] This tenet of interpretation is as integral to the presumption of validity as the tenet that all legal norms should be interpreted in conformity with Common Law principles.^[45] All these tenets, which form merely one facet of the presumption of validity, collectively underscore an even broader interpretative principle: that every aspect of any legal text should be construed in a way that it has some effect.^[46] After all, ‘an interpretation that renders a provision invalid (unlawful) “obstructs” its application to the maximum.’^[47]

With these conceptual preliminaries laid out, we may begin to explore the chronology of constitutionally conforming interpretation in the New World. Before delving into how the American model evolved over time, let us first examine some of its earliest exhibits in Supreme Court case law that led to what may be referred to as the world’s first ‘golden age’ of constitutionally conforming interpretation.

3.2 The Early Days: The Origin of the Presumption of Constitutionality

In retrospect, with fully developed concepts of constitutionally conforming interpretation in mind, it seems quite feasible to identify traces of this tenet within the English and American legal traditions very early on. Indeed, many sources traditionally recognized as forerunners of judicial review could also be regarded as precursors to constitutionally conforming interpretation. For instance, Edward Coke’s early 17th-century advocacy for the supremacy of common law over statutory law, or the even older notion – prominent in American legal thought in the 18th-century – that natural law supersedes statutory law,^[48] could be seen as incorporating assertions about legal methodology. Furthermore, if one is inclined to probe deeper, phrases resonant with constitutionally conforming interpretation can, at the very latest, be found in the Federalist Papers. Consider, for example. Alexander Hamilton’s personal declaration in Federalist No 81 (1788): ‘I admit, however, that the Constitution ought to be the standard of construction for the laws, and that wherever there is an evident opposition, the laws ought to give place to the Constitution’.^[49] Last but not least, one could easily discern the application of this canon in Supreme Court decisions predating Marbury for years.^[50]

However, drawing such conclusions solely from textual similarities or broad conceptual alignments risks imposing a narrative on historical sources that might just as plausibly not be there at all. Frequently, a critical examination of other passages within the same texts can seriously challenge the plausibility of these retrospective attributions. This is clearly illustrated in the quoted excerpt from the Federalist Papers,^[51] and in some of the pre-Marbury case law discussed in academic literature.^[52] In other cases, particularly with presumed conceptual precursors from the pre-constitutional era, one must acknowledge that projecting contemporary concepts into a vastly different historical context is akin to pure speculation. Therefore, any attempt to pinpoint the ‘actual’ first appearance of constitutionally conforming interpretation is unfortunately bound to fail due to the same epistemic constraints that undermine efforts to identify the first originator of any concept in the fields of humanities and social sciences.^[53]

With reasonable certainty, constitutionally conforming interpretation can only be traced back to after the establishment of substantive judicial review in Marbury (1803). The sequence of events that led to the widespread adoption of constitutionally conforming interpretation after this decision are illustrative for the greater narrative of this canon of interpretation.^[54] This is mainly because the questions in constitutional doctrine underpinning the Supreme Court’s judicial review competence were hotly disputed.^[55] It is well-known that the United States Constitution does not expressly empower the judiciary to examine federal laws for constitutional compliance, and the debate over its implicit authorization continues to this day.^[56] Prominent opinions saw Marbury to be an overreach of judicial authority and thus a serious infringement on constitutional separation of powers, and existing partisan controversies only exacerbated the emerging constitutional jurisdiction’s intense political struggle for survival.^[57]

Following Marbury, the Supreme Court indeed considered itself a substantive constitutional court, but a new ‘intrusion’ into the legislature by invalidating yet another congressional statute would have been politically explosive.^[58] These especially volatile external circumstances not only provoked the emergence of constitutionally conforming interpretation but facilitated what can be referred to as an early golden age of this tenet, a period in which it conceptually evolved rapidly.

The doctrine of interpreting laws in conformity with international law, which is closely related to constitutionally conforming interpretation, was applied slightly earlier in case law. In Murray v The Charming Betsy, the Supreme Court recognized this doctrine as a standing part of its jurisprudence, stating:

It has also been observed that an act of Congress ought never to be construed to violate the law of nations if any other possible construction remains, and consequently can never be construed to violate neutral rights or to affect neutral commerce further than is warranted by the law of nations as understood in this country.^[59]

By 1810, at the latest, a textbook application of the presumption of constitutionality can be found in Fletcher v Peck:

The question whether a law be void for its repugnancy to the Constitution is, at all times, a question of much delicacy, which ought seldom, if ever, to be decided in the affirmative in a doubtful case. The court, when impelled by duty to render such a judgment, would be unworthy of its station could it be unmindful of the solemn obligations which that station imposes. But it is not on slight implication and vague conjecture that the Legislature is to be pronounced to have transcended its powers, and its acts to be considered as void. The opposition between the Constitution and the law should be such that the judge feels a clear and strong conviction of their incompatibility with each other.^[60]

By 1819, the presumption of constitutionality was already entrenched. In Trustees of Dartmouth College v Woodward, Chief Justice Marshall, writing for the majority, expressed this in a way that reemphasizes the strong association between constitutionally conforming interpretation and judicial review:

The validity of a legislative act is to be examined; and the opinion of the highest law tribunal of a State is to be revised – an opinion which carries with it intrinsic evidence of the diligence, of the ability, and the integrity, with which it was formed. On more than one occasion, this Court has expressed the cautious circumspection with which it approaches the consideration of such questions, and has declared that in no doubtful case would it pronounce a legislative act to be contrary to the Constitution.^[61]

At this point, the Supreme Court had not yet developed a uniform phrasing for the presumption. For instance, in a landmark ruling in 1820, it employed the Latin description ut res magis valeat quam pereat.^[62] to express its proposition, signifying that it considers the presumption of constitutionality to be an embodiment of the effet utile principle.^[63] Yet, as the textual context reveals, the court did already recognize the presumption of constitutionality as a specific aspect of the broader principle:^[64]

For it may well be doubted whether congress are by the terms of the constitution, at liberty to purchase lands for forts, dockyards, &c. with the consent of a state legislature, where such consent is so qualified that it will not justify the ‘exclusive legislation’ of congress there. It may well be doubted if such consent be not utterly void. ‘Ut res magis valeat quam pereat,’ we are bound to give the present act a different construction, if it may reasonably be done; and we have not the least hesitation in declaring that the true interpretation of the present provisio leaves the sole and exclusive jurisdiction of Fort Adams in the United States.^[65]

However, no more than seven years later, the Supreme Court’s phrasing approached what is now the standard definition of the presumption of constitutionality.^[66] In Ogden v Saunders, the notion of the presumption as a rule of doubt and its procedural law facet have already been clearly articulated:

But if I could rest my opinion in favour of the constitutionality of the law on which the question arises, on no other ground than this doubt so felt and acknowledged, that alone would, in my estimation, be a satisfactory vindication of it. It is but a decent respect due to the wisdom, the integrity and the patriotism of the legislative body, by which any law is passed, to presume in favour of its validity, until its violation of the constitution is proved beyond all reasonable doubt.^[67]

3.3 The American Model’s Middle Ages: How the Presumption of Constitutionality Evolved Over Time

By 1827, the conceptional foundations of the presumption of constitutionality were essentially established. Particularly until the infamous Dred Scott v Sandford,^[68] decision, when the Supreme Court felt compelled for the second time in its history to invalidate a statute – the Missouri Compromise – due to its unconstitutionality,^[69] constitutionally conforming interpretation continued to play a significant role. Case law spanning the fifty-four years from Marbury to Dred Scott exemplify the strategy of ‘constitutionally conforming interpretation instead of declaring a statute unconstitutional’ more vividly than almost any other era.^[70]

Around the time of the Dred Scott decision, the political circumstances surrounding the Supreme Court once more began to change significantly. The Court not only grew bolder in its self-conception as a constitutional court, but the domestic political climate worsened progressively, culminating in the Civil War (1861–1865). In light of these circumstances, it is hardly surprising that the doctrinal development of the presumption of constitutionality did not advance significantly for the remainder of the 19th century. Hence, Chief Justice Morrison Waite’s 1878 opinion for the Court in The Sinking Fund Cases consistently upheld the stance previously taken in Ogden:

Every possible presumption is in favor of the validity of a statute, and this continues until the contrary is shown beyond a rational doubt. One branch of the government cannot encroach on the domain of another without danger.^[71]

This trajectory in case law can be traced consistently up to the early 20th century, with landmark cases such as Sweet v Rechel (1895),^[72] and Home Telephone & Telegraph Co v Los Angeles (1909),^[73] all more or less reiterating the same concept.^[74] Around that time, the view gradually began to take hold that the presumption of constitutionality represents a flexible interpretative criterion. More frequently, it was stressed that it ‘is a rebuttable presumption’ and not ‘a rule of law […], which makes legislative action invulnerable to constitutional assault’.^[75] This refinement of the general presumption of consitutionality was further delineated across different areas of law, achieving a systematic form by the 1940s.^[76] In the decades that followed, up to the present day, this system has been considerably honed and continues to be prominently applied in case law.^[77]

3.4 The New American Model: Introducing the Constitutional Avoidance Canon

While the presumption of constitutionality has maintained its distinct role in American legal methodology,^[78] the early 20th century saw the development of an interpretative tenet that is similar in purpose:^[79] the ‘constitutional avoidance canon’ or ‘constitutional doubt canon’. According to the definition adopted in this article,^[80] it may also be considered a version of constitutionally conforming interpretation,^[81] and a strategy for courts to refrain from declaring a statute unconstitutional. As the progression in case law suggests, this new version of constitutionally conforming interpretation evolved directly from the presumption of constitutionality. Before broadly sketching its origins, let us first explore its theoretical underpinnings.

The constitutional avoidance canon extends beyond the presumption of constitutionality. This canon has been formulated in various ways, yet one rule perhaps best encapsulates it, which was articulated by the Supreme Court a full 27 years before the ruling that led to the canon sometimes being referred to as the ‘Ashwander principle’:^[82]

[T]he rule plainly must mean that, where a statute is susceptible of two constructions, by one of which grave and doubtful constitutional questions arise and by the other of which such questions are avoided, our duty is to adopt the latter.^[83]

Like the presumption of constitutionality, this canon of interpretation serves as a selection rule that addresses ambiguities remaining after other interpretive criteria have been applied to a statute. ‘The canon of constitutional avoidance comes into play only when, after the application of ordinary textual analysis, the statute is found to be susceptible of more than one construction.’^[84] Compared to the presumption of constitutionality, the constitutional avoidance canon takes effect sooner in the interpretation process. It rules out not only unconstitutional interpretations but also interpretations that would raise serious concerns about the statute’s constitutionality.

Traditionally, constitutional avoidance is justified by judicial restraint considerations, similar to those supporting the presumption of constitutionality.^[85] With this canon, courts take this idea one step further, not merely shying away from attributing unconstitutionality to a law, but also avoiding intricate discussions of the Constitution that would be necessary to find out whether a proposed statutory construction is constitutional or not. In effect, the canon allows to preemptively circumvent constitutional adjudication in many cases altogether.

In academic literature, it is often argued that the constitutional avoidance canon comprises two distinct concepts.^[86] The first is a genuine methodological one, while the second is primarily a procedural notion that Justice Brandeis articulated as ‘[t]he Court will not pass upon a constitutional question, although properly presented by the record, if there is also present some other ground upon which the case may be disposed of.’^[87] Considering the constitutional avoidance canon’s development from the presumption of constitutionality and its close conceptual relation to it, it seems more accurate to view these as two facets of the same principle. Like the presumption of constitutionality, recognized for its inherent procedural dimension that aligns with the common law judge’s role, the constitutional avoidance canon also embodies a procedural aspect – arguably a much more significant one. While functioning as a genuine canon of interpretation outside the courtroom, within judicial proceedings, it will be for the challenging party to present alternate (non-constitutional) grounds for the matter to be resolved.^[88]

With these conceptual preliminaries in place, we may explore how the canon has evolved in the case law of the Supreme Court.

3.5 Where the Constitutional Avoidance Canon Came From

The constitutional avoidance canon marks a major evolution, frequently linked to 1936 due to its occasionally used designation as the ‘Ashwander principle’.^[89] Even though the principles set forth by Justice Brandeis in his concurring opinion in Ashwander v Tennessee Valley Authority,^[90] represent an early and explicit instance of the canon’s application, its roots extend back several decades further.

This is initially indicated by the fact that Ashwander is not acknowledged as the foundation of this interpretive tenet in subsequent case law. For instance, Justice Butler’s articulation of the canon in his concurring opinion in United States v Carolene Products Co.^[91] (‘The provisions on which the indictment rests should, if possible, be construed to avoid the serious question of constitutionality’) does not refer to Ashwander at all.

According to my analysis, the earliest traces of an evolution of the constitutional avoidance canon from the presumption of constitutionality can be found in Knights Templars Indem. Co. v Jarman, which first proposed that the clarity of an interpretation’s constitutionality can influence its interpretation:

Were the act of 1887 more ambiguous than it is as to its application to past transactions, we should still be disposed to apply the cardinal rule of construction that, where the language of an act will bear two interpretations equally obvious, that one which is clearly in accordance with the provisions of the Constitution is to be preferred.^[92]

Soon after, a re-statement of that approach – from prioritizing interpretations that are unequivocally constitutional to avoiding ones that might be unconstitutional – is evident in Harriman v Interstate Commerce Commission, which expands on the ‘cardinal rule’ set out by Knights Templars:

If we felt more hesitation than we do, we still should feel bound to construe the statute not merely so as to sustain its constitutionality, but so as to avoid a succession of constitutional doubts, so far as candor permits.^[93]

The progression of the presumption of constitutionality into the constitutional avoidance canon is clearly illustrated once more in United States v Delaware & Hudson Co.^[94] Alongside providing the most lucid rule-based formulation of this canon,^[95] this judgment also reveals, more explicitly than any prior case, the judicial reasoning that connects the new canon to its predecessor:

It is elementary when the constitutionality of a statute is assailed, if the statute be reasonably susceptible of two interpretations, by one of which it would be unconstitutional and by the other valid, it is our plain duty to adopt that construction which will save the statute from constitutional infirmity. […] And unless this rule be considered as meaning that our duty is to first decide that a statute is unconstitutional, and then proceed to hold that such ruling was unnecessary because the statute is susceptible of a meaning which causes it not to be repugnant to the Constitution, the rule plainly must mean that, where a statute is susceptible of two constructions, by one of which grave and doubtful constitutional questions arise and by the other of which such questions are avoided, our duty is to adopt the latter.^[96]

From United States v Delaware & Hudson Co onward, the constitutional avoidance canon has been a steadfast element of Supreme Court case law. It was solidly established in dicta.^[97] and recognized as common judicial practice well before Ashwander. Instead of supplanting the presumption of constitutionality, the constitutional avoidance canon seamlessly integrated into the Supreme Court’s methodology. Applied alongside the presumption of constitutionality, both interpretative tenets form a very strong version of constitutionally confirming interpretation. The harmonious coexistence and combined application of both canons are exemplified notably in Cromwell v Benson:

When the validity of an act of the Congress is drawn in question, and even if a serious doubt of constitutionality is raised, it is a cardinal principle that this Court will first ascertain whether a construction of the statute is fairly possible by which the question may be avoided.^[98]

With Justice Brandeis’ concurrence in Ashwander v Tennessee Valley Authority,^[99] the constitutional avoidance was placed on a broader footing, expressing clearly in various ways a general methodological principle that ‘constitutional adjudication is to be treated as a “last resort”’.^[100] Yet, its conceptual development had largely concluded by then.^[101]

Henceforth, the American model of constitutionally conforming interpretation would be two-layered. Although the presumption of constitutionality and the constitutional avoidance canon exhibit different characteristics, they are unified in their objective to ensure that statutes align with constitutional principles, thereby avoiding the necessity of declaring statutes unconstitutional. The next section of this article will turn to the historical development of constitutionally conforming interpretation in Europe, setting the stage for a final comparison of the New and Old Worlds’ approaches in section 5.

4.1 The European Story

The evolution of constitutionally conforming interpretation in Europe parallels the historical trajectory observed in the United States. Since the necessary external conditions were established much later on the other side of the Atlantic, the European story begins about a century after the presumption of constitutionality was first applied in Supreme Court case law.^[102] Although the American model of constitutionally conforming interpretation was well-entrenched by then, it did not directly shape the development of this tenet in Europe. Rather than being a derivative of foreign jurisprudence, it was independently developed in Western Europe based on the ‘intrinsic necessities of every judicial review procedure.’^[103] This independent genesis in the context of the old world’s institutional frameworks and the civil law tradition has fostered nuanced differences in the approach to constitutionally conforming interpretation when compared to the original American model.

In Europe, a largely uniform, single-layered model of constitutionally conforming interpretation has emerged across its various constitutional systems.^[104] Of course, slight conceptual variances occur, and there are some outliers, which mostly stem from minor or major differences in the constitutional court system.^[105] Yet, this situation is not markedly different from that within the American legal system, where, despite state-specific nuances and occasional systematic deviations,^[106] a uniform, two-layered model has been traceable in its development. Of course, unlike in the United States, during the period studied, Europe lacks a Supreme Court whose case law could serve as a fundamental authority for deriving a European model. Given that the Austrian (Kelsenian) model of constitutional adjudication is the predominant framework for constitutional courts in Europe,^[107] the European model will subsequently be developed primarily from its most distinct national proponents.^[108]

As in the United States, constitutionally conforming interpretation in Europe is commonly defined from the perspective of judicial review procedures. Its purpose lies in preserving a statute’s validity, and it is accepted as a strategy for resolving conflicts between constitutional and sub-constitutional statutes through interpretation.^[109] As an interpretative cornerstone, it mandates that all statutes be construed ‘in accordance with constitutional principles.’^[110] Defined more specifically as a rule of selection, it specifies that among multiple interpretations derived from other interpretative canons, any interpretation that fails to align with constitutional law must be disregarded. When a statutory text is open to various interpretations, those interpretations that are unconstitutional are excluded, limiting the possibilities to those that comply with the constitution.^[111] The German Constitutional Court explains the tenet in the following way:

The mandate of constitutionally conforming statutory interpretation stipulates that, from multiple possible interpretations which may lead to either unconstitutional or constitutional outcomes, the interpretation that aligns with the Basic Law should be preferred. Therefore, a norm should only be declared unconstitutional if no interpretation permissible under recognized interpretative principles and compatible with the constitution is possible. If the wording, legislative history, overall context of the relevant regulations, and their purpose and objectives allow for multiple interpretations, one of which leads to a constitutional result, this interpretation is required.^[112]

The European model of constitutionally conforming interpretation, unlike its American counterpart, has not evolved through a two-stage development and is not divided into two distinct canons. It does not incorporate the stronger trajectory of the constitutional avoidance canon, which seeks to preempt interpretations that might raise substantial constitutional issues. Currently, there is no indication in European jurisprudence suggesting a shift toward this approach.^[113] At first glance, the European model appears similar to the American presumption of constitutionality.^[114] However, this apparent similarity fades when considering the procedural nuances inherent in the American model. European legal doctrine does not attribute any procedural or evidentiary role to constitutionally conforming interpretation. While sometimes framed in terms of a ‘presumption in favor of a statute’s constitutionality,’^[115] it is not understood as imposing a procedural burden of proof. Instead, it merely implies that compelling legal arguments are required to deem a statute unconstitutional,^[116] and that judges must exhaustively seek a constitutionally conforming interpretation before nullifying a statute.^[117]

The emergence of constitutionally conforming interpretation in Europe cannot be thoroughly explained without acknowledging the socio-political context of the turn of the 20th century, even more so within the Austrian model of constitutional adjudication. Particularly when the role of the constitutional court is considered primarily as that of a ‘negative legislator’,^[118] the adoption of constitutionally conforming interpretation becomes contingent. Parts of Austian and German literature even make the case that these institutional conditions imply that constitutional courts must prefer annulment when there are doubts about the constitutionality of statutes.^[119] Despite these doctrinal concerns and a coherent methodological alternative to constitutionally conforming interpretation in place, European constitutional courts and other high courts uniformly pursue the strategy of ‘constitutionally conforming interpretation instead of declaring a statute unconstitutional’ as vigorously as the US Supreme Court.

Even in German-speaking scholarship, that is traditionally reluctant to accept non-legal explanations for legal phenomena, it is accepted that the emergence of this tenet is attributable to the recognition of the ‘drawbacks of repressive norm control’.^[120] Genuine sociological studies are traditionally rare in the German legal context and remain so. Nevertheless, a strong non-legal motivation for adopting constitutionally conforming interpretation can not be denied, mostly pointing towards an inherent motivation to avoid the consequences of judicial review.^[121]

With this conceptual groundwork in place, let us now examine the historical development of constitutionally conforming interpretation in the Old World.

4.2 The Emergence of Constitutionally Conforming Interpretation in Europe

It was not until the latter half of the 20th century that constitutionally conforming interpretation became prevalent in Europe, directly trailing the post-World War II rise of constitutional courts modeled after the Austrian system throughout Western Europe. In 1883, the German Reichsgericht explicitly rejected the notion that there is a duty for the Court to choose a constitutional construction of a statute over an unconstitutional one.^[122] The early decades of the century can be identified as an exploratory phase, during which initial traces of this interpretative approach began to emerge in the rulings of (the few already existing) constitutional courts or other high courts, with these concepts being further developed and refined in legal scholarship. However, the term ‘constitutionally conforming interpretation’ did not appear in Europe until much later.^[123]

Mirroring the chronology in the United States, the conformity concept in European legal methodology was first developed with regards to international law. One of the earliest pieces of evidence can be found in German literature, with Heinrich Triepel’s 1899 monography on the relationship between international law and state law possibly featuring the first European elaboration on the idea that two layers of law can be reconciled by legal interpretation.^[124] The interpretative concept of constitutionally conforming interpretation was likely applied for the first time by the Federal Supreme Court of Switzerland in 1908. In BGE 34 I 528, the Court relied on a ‘general rule of interpretation’ that can be reconstructed as a vague notion of our tenet:

according to the general rule of interpretation, a provision must be interpreted in case of doubt in such a way that it remains within the framework of the Constitution.^[125]

Despite such early examples of a confessional recognition of this tenet in high court judgments, it was unable to establish itself at that time.^[126] However, over the subsequent decades, Swiss scholarship continued to refine this principle, eventually formulating it into a comprehensive rule. Echoing the progression seen in America, the initial descriptions clearly indicate that constitutionally conforming interpretation was conceived entirely within the framework of judicial review. Hans Reichel, writing in 1926 within the Swiss context, concisely expressed this idea as follows:

We describe a law that violates the Constitution or state treaties as null. Yet, such a drastic measure should only apply when the conflict is clear. Where there may be any doubt, it must be resolved in favor of compatibility. Conclusion: in doubt, every law should be construed to comply with its constitutional and state treaty obligations.^[127]

The Weimar Republic era (1918–1933) was a crucial period for the evolution of constitutionally conforming interpretation, with the German Reichsgericht playing a leading role in its recognition and development. Particularly noteworthy is the decision RGZ 102, 161 (1921), which not only rooted constitutionally conforming interpretation in the Weimar Constitution’s legal framework but also clearly expressed for the first time that this tenet signifies the constitutional supremacy over statutory law.

The wording of Article 153, along with the significance of the constitutional provisions, particularly the fundamental rights envisioned as the sanctuary of the German people, indicate the necessity that any legal norm creating an exception to these rights must clearly declare itself as such.^[128]

It is no coincidence that the Weimar Republic would become a significant development field for constitutionally conforming interpretation, as there are noteworthy parallels in the evolution of constitutional adjudication with that in the United States following Marbury v Madison. While the judiciary possessed judicial review competencies,^[129] the Reichsgericht exercised this power with the greatest restraint.^[130] Similarly to how the early US Supreme Court utilized the presumption of constitutionality as a strategic tool to sidestep the perilous actions of nullifying laws, the Reichsgericht also sought suitable interpretative alternatives to achieve desired legal outcomes in a politically less challenging way.

The fact that constitutionally conforming interpretation was applied more frequently and consistently by the US Supreme Court than by the Reichsgericht under similar circumstances,^[131] and that it had not yet fully taken hold in Europe during the first half of the 20th century, can be attributed to a subtle nuance in the legal methodology prevalent at that time. The aim to uphold the greatest possible extent of a legal norm while avoiding its formal nullification was frequently achieved by declaring the norm partially invalid, rather than completely abolishing it.^[132] As noted by Wolf-Dieter Eckhardt, those decisions of the Reichsgericht that employed this alternative strategy show remarkable similarities to early Federal Constitutional Court decisions in which it applies constitutionally conforming interpretation. Although this approach would be regarded as invalid or deceptive today, its adoption at the time may explain why it took so long for constitutionally conforming interpretation to take hold in Europe.^[133]

The theoretical underpinnings of constitutionally conforming interpretation were progressively formulated within legal academia, following the jurisprudence of the Reichsgericht. Notably, Günther Holstein made significant contributions to its development by initially proposing that fundamental rights, when enshrined in a statute that is formally part of the Constitution, play a decisive role in the interpretation of statutes which may interfere with them,^[134] and he aptly predicted their rising relevance in legal interpretation.^[135] Equally noteworthy is, among others, the contribution of Albert Hensel, who, building on Reichsgericht judgments, seems to first have systematically sketched some methodological boundaries of constitutionally conforming interpretation and has reflected on its application from a theoretical perspective.^[136]

While the study of constitutionally conforming interpretation at the time, thus, started to reveal some systematic features, a deep and coherent understanding of this tenet was still not achieved in the interwar period. It is with considerable regret that one must note the theoretical development of the idea of conformity is, to some extent, linked to the era of the Third Reich (1933–1945).^[137] In order to comply with the demand that ‘[t]he basis of the interpretation of all legal sources is the National Socialist worldview, as expressed in particular in the party program and in the Führer’s statements’,^[138] prominent legal scholars reflected on the conforming interpretation canon.^[139] Of course, these works could not be expected to accurately capture the tenet due to the absolute priority given to National Socialist values in the interpretation process at that time.

4.3 Constitutionally Conforming Interpretation’s Triumph in the Post-War Period

In the aftermath of World War II, Western Europe embraced a new constitutional ethos, with a strong emphasis on the binding force of substantive constitutional norms over all branches of government.^[140] Furthermore, the Austrian model of constitutional review was broadly implemented,^[141] setting up the institutional framework that usually precipitates the rapid establishment of constitutionally conforming interpretation.^[142]

Pinpointing the precise moment when the triumph of this interpretative tenet began is, due to the vast array of historical sources, open to interpretation itself. For example, immediately after the war ended, a version of constitutionally conforming interpretation was implemented in Austrian positive law, with the Constitutional Law from May 1, 1945, concerning the provisional setup of the Republic of Austria (Provisional Constitution),^[143] demanding:

All legislation shall be drafted in accordance with the principles of the form of government of a democratic republic and shall be interpreted in accordance with these governing principles.^[144]

When disregarding positive law sources, several candidates for the first occurrence in post-war Constitutional Court judgments have been proposed in the literature, ranging from the Austrian Constitutional Court,^[145] to the Bavarian Constitutional Court,^[146] and the Baden State Court of Justice.^[147] The latter suggestion is probably the correct one,^[148] dating the beginning of an impressive wave of exponential expansion of constitutional conforming interpretation in Western Europe to early 1950. The relevant difference between these applications in judgments and those dating to the pre-war period lies in the tenet now being recognized and consistently enforced by the applying courts.^[149] The dominant phrasing of constitutionally conforming interpretation as a rule of doubt was already present by 1951 in Austria.^[150] The German Federal Constitutional Court, which was established in 1951, might have adopted this canon already in its first year.^[151] Its most prominent landmark decision, first explicitly mentioning constitutionally conforming interpretation (verfassungskonforme Auslegung), dates to 1953:

This is all the more necessary because it is a generally accepted principle that a law should not be deemed void if it can be interpreted in a manner consistent with the constitution; this implies not only a presumption of a law’s compatibility with the Basic Law but also that the principle expressed by this presumption requires a constitutionally conforming interpretation in cases of doubt. Naturally, the legislative intent must not be overlooked^[152]

By the end of the 1950s, constitutionally conforming interpretation had mostly completed its early triumphant march in Western Europe.^[153] While most national doctrines do not yet regard the European Treaties as a Constitution, the development of a similar canon of interpretation stemming from the supremacy of European Law can be evidenced in the immediate aftermath of European integration, already shortly after the founding of the European Coal and Steel Community.^[154] Following the establishment of the European Court of Justice, its case law drove the development of conforming interpretation canons further.^[155]

The narrative of a triumph that has been depicted here for Western Europe after World War II can also be applied to Eastern Europe following the democratic transition in the late 1990s. For example, in the Czech Republic, Hungary, and Poland, constitutionally conforming interpretation was promptly adopted as a fundamental component of judicial practice immediately following the establishment of constitutional states and the introduction of genuine constitutional courts.^[156]

As this survey shows, there is a clear trajectory of constitutionally conforming interpretation to be observed in Europe, leading to its uniform acceptance across its legal systems. Moving forward, this narrative serves as another testament to the adaptive and enduring nature of this interpretative tenet. The final section will conclude with a comparison of the American and European models of constitutionally conforming interpretation.