1. Introduction
Hans Kelsen's vast body of work is perhaps one of the best examples of the unremarkable but important point that one's legal theory and methodological choices are intricately tied up with how one understands international law. Kelsen stands for a huge number of different positions, but chief amongst them must be his insistence on developing a ‘pure’ theory of law that accounted for the unique normativity of law, separate from empirical facts and causality on the one hand, and substantive theories of justice on the other.Footnote 1 For Kelsen, the unique normativity of law is found within the legal system itself, in the idea of normative imputation – the ‘linking of a conditioning material fact with a conditioned consequence’.Footnote 2 According to Kelsen, this specifically legal sense of ‘ought’ is an a priori category that allows us to correctly cognize the legal meaning of empirical data.Footnote 3
Kelsen's view of international law is similarly nomological.Footnote 4 For him, international law is law in the same sense as national law, despite having important differences.Footnote 5 International law, like national law, confers rights and obligations on individuals, although it often refers to them in their capacity as state officials.Footnote 6 States, for Kelsen, are not pre-legal monolithic beings, but distinct legal orders, bundles of rights and obligations.Footnote 7 According to Kelsen, to conceive of a binding international law we must presuppose that international law itself is sovereign, in the sense of being the highest legal order, sitting above, and ultimately explaining the validity of, state legal orders.Footnote 8 For Kelsen, ‘[p]hysical power . . . can never be sovereign’; it exists in the fundamentally different sphere of facts and causality.Footnote 9 Kelsen's international law obviously contrasts sharply with more ‘realist’ views which argue that it is dangerous to see a distinct legal type of normativity in international relations where there are only unrestrained contests for power, and I will address this below. Kelsen's international law also contrasts with overtly value-laden theories of international law.Footnote 10 However, I will argue that despite Kelsen's claim to objectivity, his work rests on certain liberal ideas, above all prioritizing the rule of law and reflecting pervasive scepticism towards ideas of substantive justice.
Both of the books under review advocate the view of law as a specific normative medium in international relations, distinct both from facts and power, and from substantive theories of justice. Jochen von Bernstorff in The Public International Law Theory of Hans Kelsen: Believing in Universal Law argues that Kelsen's legacy for contemporary international law is ‘the belief in the potential value of systemic international legal validity, as a notion that cannot be fully dissolved into power, utility, morality, or any other external rationality’.Footnote 11 Jörg Kammerhofer too, in Uncertainty in International Law: A Kelsenian Perspective, clearly values a distinct realm of legal validity. Indeed, he has elsewhere claimed that international lawyers must confine themselves to this realm.Footnote 12 Kammerhofer takes a strong and consistent methodological stance throughout his book, continually reminding the reader that law exists in the realm of ought, not the realm of is. So, for Kammerhofer, ‘brute fact [say, of state consent] neither is nor makes law’, and effectiveness, a factual matter, ‘is not [legal] validity’.Footnote 13 Further, legal validity does not say anything about a norm's moral merits.Footnote 14
This review essay will argue that, while important criticisms can be made of a Kelsenian approach to international law, as long as the perspective is endorsed with an attempted awareness of its biases and vulnerabilities to critique,Footnote 15 it offers some valuable insights through its focus on legal form and legal validity in international relations. Specifically, the perspective may help promote a modicum of procedural justice in international relations through its view of law as a medium that is never wholly reducible to the preferences or ideologies of particular actors.Footnote 16 Emphasizing legal form – as opposed to other functionalist rationalities, say power, morality, or economic efficiency – can further the Fullerian ideals of accountability and reciprocity.Footnote 17 It promotes a setting in which legal argument is ‘available to all under conditions of equality’.Footnote 18 Obviously, these are only limited values – centred around the idea of formal equality – and other perspectives offer important vantage points that deserve attention, but these are not my focus here.
I will begin by giving an overview of the two books under review and commenting on their very different styles, despite their similar subject matters (section 2). I argue that Kammerhofer's book is a form of structural analysis, seeking to apply the rigour of the Pure Theory to improve our theoretical awareness within contemporary doctrinal controversies, whereas von Bernstorff's is a historical analysis, trying to improve our self-understanding as contemporary international lawyers by looking in detail at the debates of Kelsen's day.Footnote 19 I will then address some potential challenges to Kelsenian methodology (section 3). I argue that despite the Vienna school's claim to objectivity, it should be understood as engaged in a fundamentally liberal project, with important political consequences, that seeks to put law at the centre of our understanding of international relations (3.1). I also examine potential objections to Kammerhofer's insistence on the is/ought distinction (3.2), and the important realist criticism that the Pure Theory may blind us to political realities, specifically that the powerful may move to displace existing law (3.3). In section 4, I consider the Vienna school's famous view of law as a monistic whole, for the limited purpose of arguing that both books under review share Kelsen's conception of an international law sitting above its subjects. Finally, I will consider the two authors’ views on interpretation; they, following Kelsen, see indeterminacy as highly significant but ultimately limited (section 5). I suggest that those of a more critical persuasion will see any limitations on interpretation, and, accordingly, the possibility of any modicum of procedural justice under law, as unconvincing.Footnote 20 Others, in contrast, will share the authors’ Kelsenian view that while indeterminacy is highly significant, interpretive discretion remains limited.
2. Overview of the two books and their significant stylistic differences
Kammerhofer's book aims to apply Kelsen's Pure Theory to current problems of international law, arguing that a Kelsenian perspective ‘promises to have beneficial results for the study of international law’.Footnote 21 There are chapters deconstructing contemporary debates on: the scope of the right to self-defence, the concept of customary international law, approaches to treaty interpretation and the question of subsequent practice modifying treaty norms, conflict of norms and the conflict-resolving maxims invoked in such debates, and whether international law has a ‘material’ constitution enunciating the forms law can take and how law can be changed.Footnote 22 A final chapter operates at a higher level of abstraction, providing a rich explanation of Kelsen's idea of the Grundnorm and attempting to justify the strong methodological stance deployed throughout the book, grounded on the distinction between the realms of ought and is.
In my view, Kammerhofer's book is important, above all, for showing how much less we know about positive international law than is typically assumed, and how dependent our knowledge is on the theoretical assumptions we employ, even if they are often not examined transparently. One of Kammerhofer's aims is to show the need for international legal scholarship to be more aware of its theoretical basis.Footnote 23 In my view, he succeeds in spades in achieving this aim. As Bruno Simma remarks in the Foreword, the book operates as ‘a kind of “anti-Brownlie”’, constantly demonstrating that fundamental, recurring doctrinal controversies become clearer if we confront the legal theoretical differences that underlie them.Footnote 24 The book deserves serious attention, particularly from those interested in understanding doctrine in a theoretically informed way, given its extremely careful argumentation, its explicit treatment of numerous topical and often overlooked issues, and its provocative critiques of many orthodox understandings.
Kammerhofer's other aim is ‘to connect German-speaking scholarship and the English legal tradition’.Footnote 25 In the English-speaking world, Kelsen's work is only studied by a small number of specialists and is regarded by many, even if they have not spent much time grappling with its complexities, as outmoded legal theory. Kammerhofer seeks to ‘extend an invitation to re-engage with Kelsen's thoughts’, and he offers a highly sophisticated understanding of Vienna school jurisprudence that would please many Kelsen specialists. Kammerhofer's explorations of the intricacies of Kelsenian theory are more detailed than von Bernstorff’s, but, probably for this reason, more difficult to follow. I doubt that the book will cause many non-Kelsenians to embrace the methodology, simply because, as Kammerhofer himself notes, at the highest levels of abstraction, ‘the air gets very thin, so to speak’, and the Pure Theory, like legal theories generally, is a dogma that is either accepted or not.Footnote 26 As noted above, I think Kammerhofer's book offers a range of valuable insights even for those who ultimately disagree with his methodology and the conclusions it produces. English-speakers who do not read German will be very impressed by the extensive original translations Kammerhofer provides – both of Kelsen and of much other German literature cited. This is itself a contribution to bridging the cultural gap he identifies.
Von Bernstorff's book also helps bridge this gap, providing valuable access to the historical development of the German international law tradition for an anglophone audience. His book is an intellectual history of Kelsen and his key students’ theories of international law, first published in German in 2001 and now translated with the author's collaboration into English. In addition to Kelsen there is treatment of several of his students, particularly Joseph Kunz and Alfred Vedross. The book begins with a chapter on ‘[m]ethod and construction of international law’ in German international law scholarship during the second half of the nineteenth century, providing a real sense of the scholarship that preceeded Kelsen and the context in which his Pure Theory emerged. Von Bernstorff wants to explain ‘the specific orientation and inner structure of Kelsen's works on international law [by situating them] against the debates of . . . his day’.Footnote 27 Von Bernstorff makes a significant attempt to assess the contemporary relevance of Kelsenian formalism in a new Postscript, which will likely interest even those who have read the original text in German.
Von Bernstorff's book is, in my view, a valuable contribution for quite different reasons to Kammerhofer’s, reflecting an important difference in styles between the two books. Essentially, von Bernstorff's book is less concerned with the detail of doctrinal disputes but is pitched at a higher level of abstraction, focusing instead on what overarching themes in the debates of Kelsen's time may teach us as contemporary international lawyers. It is undertaken in a similar style to Martti Koskenniemi's Gentle Civilizer Footnote 1 and, interestingly, that book and von Bernstorff's original in German both appeared in 2001, towards the start of a revival in the study of international law's histories.Footnote 29 Like Koskenniemi, who wanted to focus on ‘a sensibility that connotes ideas and practices but also involves broader aspects of the political faith, image of self and society’,Footnote 30 von Bernstorff is clear that behind his interpretation of Kelsen's legacy as a sensibility for the unique social medium of international lawFootnote 31 ‘stands the question about the self-understanding and role of the international lawyer as both a scholar and a political individual’.Footnote 32 This question remains highly relevant todayFootnote 33 and that, essentially, is why this type of detailed historical reconstruction is valuable – by examining, in context, the views of previous generations in our intellectual tradition we can increase our self-understanding and gain a better sense of the possibilities (and limits) of international law today.Footnote 34
In contrast to von Bernstorff's efforts to situate Kelsenian thought in a broader context, Kammerhofer, having made a decision to employ the Pure Theory, seeks throughout his book to consistently apply it to contemporary international law controversies to see ‘what benefits and problems this engenders’.Footnote 35 Kammerhofer's book is deliberately pitched as not ‘simply being a piece of intellectual history’,Footnote 36 and he has elsewhere made clear an aim of applying the Pure Theory, as a general theory of law, ‘a-contextually and a-historically’ to current international legal problems.Footnote 37 Kammerhofer's efforts to maintain theoretical consistency are impressive. He advocates a form of scholarship not afraid to carry its analysis through ‘to the bitter end’, and wants to oppose any form of pragmatism that would bow to what is convenient or realistic within the everyday ‘realities’ of international law.Footnote 38 I have already hinted that I see this refusal to bow to extra-legal rationalities as valuable because it can promote a degree of procedural justice in international relations.Footnote 39 Kammerhofer's style, however, has the potential to come across as hard line. Criticisms of his Kelsenian-inspired perspective are consistently rebutted, often by falling back on the Pure Theory's methodological premises, for example the fundamental is/ought distinction. This reflects a disadvantage of Kammerhofer's style: because he spends far less time than von Bernstorff situating Kelsen in a wider context, unfamiliar readers will have less of an idea of why the Pure Theory adopts particular – often quite foreign – perspectives.
Despite this, it would be wrong to characterize Kammerhofer as a methodological dogmatist. Indeed, he notes that other methodological approaches are ‘entirely possible and on a philosophical level equally plausible’. Kammerhofer points out that this ‘relativistic approach is itself wholly in line with the Pure Theory's consistent value relativism’ which holds there is no ‘right’ methodological approach to take, but merely competing values that can be described.Footnote 40 In my view, this stance, common to recent positivist writing in international law, is useful in emphasizing that it is up to each of us to choose our own methodology, and that different perspectives may offer distinct insights.Footnote 41 In this spirit, I think the stylistic difference between the two books can be seen as reflecting two different modes of international legal scholarship, each offering us different insights: Kammerhofer's book in relation to the theoretical consistency of doctrine and von Bernstorff's in relation to the wider project we see ourselves pursuing. Ultimately, all of this seems to reflect that Kammerhofer's book is a form of structural analysis, focused on applying the rigour of the Pure Theory to improve the quality of doctrinal argument, which largely does not seek to situate Kelsen in a particular context. In contrast, von Bernstorff's book is a historical analysis, trying to understand Kelsen as pursuing particular political projects and to draw lessons from this.Footnote 42
3. Some challenges to Kelsen's methodology
3.1. Kelsen's quest for objectivity
What should we make of Kelsen's claim to pursue an ‘objectivist’Footnote 43 legal science, ‘as exact a structural analysis of the positive law as possible, . . . free of all ethico-political value judgments’?Footnote 44 First, we can note the striking similarity between Kelsen and Kammerhofer's self-understanding of their projects, perhaps unsurprising given Kammerhofer's aim to apply the Pure Theory. Kammerhofer sees himself as following in this tradition, striving, like Kelsen, to cognize what positive international law exists free of external elements.Footnote 45 At the outset, he explains that the ‘Vienna School of jurisprudence is a Modernist movement’ aimed at perceiving law ‘in the most objective fashion possible’, so, while acknowledging ‘that the notions of “objectivity” and “truth” are problematic . . . they would not consider ceasing to strive for a scientific perception of law in favour of a pragmatic or political conception’.Footnote 46 In his first chapter, on self-defence, we get a good example of what this entails: Kammerhofer excludes from consideration ‘arguments of purely political or moral nature, or calculations of efficacy’ – for example whether or not anticipatory self-defence is desirable given modern technology – as these cannot influence what positive law is.Footnote 47 Obviously, Kammerhofer's perspective contrasts sharply with functionalist perspectives that would see positive law as having to adjust to modern realities. Kammerhofer's positioning, of emphasizing legal form and validity, may offer one way of promoting values that can be furthered by a non-instrumental view of law. However, it should be seen not as somehow more ‘objective’, but as a thoroughly political intervention that chooses to work from a paradigm of a legally regulated sphere of international relations. This reflects the broader point that Kelsen's Pure Theory – contrary to his claim of objectivity – relies on some profoundly liberal values, above all promoting the ideal of the rule of law, which is strictly separated from substantive theories of justice.Footnote 48
I will expand on these claims but first it is useful to examine von Bernstorff's exploration of the ‘objectivity’ issue, as the original German edition of his book was criticized for its attempt to link Kelsen's asserted methodologically ‘pure’ understanding of law and his cosmopolitan views on international relations. Essentially the critique was that showing that Kelsen's legal views have political results is not the same as establishing that Kelsen used political arguments in his legal reasoning, contrary to his own methodological premises.Footnote 49 Von Bernstorff clarifies in the Postscript that his intention is not to ‘impute dishonest motives to Kelsen’ but to contend that the ‘tension-filled connection between [Kelsen’s] “scientific” methodology and political project is crucial to . . . [understanding his] theory of international law’.Footnote 50 Specifically, von Bernstorff locates the connection between the two in Kelsen's deconstruction, using the Pure Theory, of ideologically loaded concepts to free up international law for use in the cosmopolitan projects Kelsen favoured.Footnote 51 The debates examined seem to fit this reading well: think, for example, of Kelsen's deconstruction of traditional absolutist notions of state sovereignty as theoretically unsound, which in turn removed a great obstacle to imagining a binding international law. However, for Kelsenian specialists, even von Bernstorff's clarified interpretation may be objectionable, not being precise enough as to the interconnection and making Kelsen ‘seem rather dishonest’.Footnote 52 Kelsen himself stated that the Pure Theory was ‘not arrived at by political design . . . [although] it may nevertheless have political import’.Footnote 53
In my view, whatever Kelsen's intentions, and accepting here that Kelsen's legal arguments abided by his methodological premises, von Bernstorff is right to point out that Kelsen's theory of international law has the effect of defending the ‘law's inherent rationalities against political, economic, and other social rationalities’.Footnote 54 Specifically, its continual emphasis on legal validity and universalistic ambitions – there are no matters inherently outside international law for KelsenFootnote 55 – reflect a distinctly liberal understanding of international relations as a law-governed space. Footnote 56 This in result is a ‘highly political project’,Footnote 57 even if not intended by Kelsen or arrived at by ‘impure’ methods. It is worth considering in more detail the type of values that might be promoted by invoking law as central to our view of international relations.
Von Bernstorff sees law as valuable because it aims for a ‘specifically formal [type of] justice’ that is useful given the ‘global plurality of interests’.Footnote 58 This sentiment is well captured in Kelsen's description of sovereign equality, quoted by von Bernstorfff: ‘Equality is the principle under the same conditions States have the same duties and the same rights’.Footnote 59 Von Bernstorff goes so far as to claim that international law becomes ‘the only available communicative medium that – by way of its formality – is capable of transcending power asymmetries and idiosyncratic preferences’.Footnote 60 One might question whether international law as understood by Kelsenian liberal legalism is really as ‘empty’ as this suggests.Footnote 61 Nevertheless, I think von Bernstorff's reading of Kelsen reminds us of something important: in an international sphere full of power disparities and moral pluralism, an insistence on legal form can sometimes be a strategy for limiting the impulses of the powerful and ensuring that other perspectives are listened to and taken into account.Footnote 62 Emphasizing legal form at least keeps open the possibility that the weak might utilize that form to articulate their claims in universal terms,Footnote 63 rather than being ‘left with little more than “private” acts of non-conformity with which’ to resist domination according to some extra-legal rationality.Footnote 64 Positive law, ‘by its refusal to be merely a translation of something beyond itself’, can allow us to recognize shared standards but also to protect ourselves from assimilation.Footnote 65 A good example of this is the principle of sovereign equality, which has arguably secured some minimal degree of procedural equality between vastly unequal states, and curbed military intervention in the post-1945 international legal system.Footnote 66
Kammerhofer, as outlined above, may reject the reading of his book as driven by anything more than a desire to analyse positive law, but in my view it has the effect, like Kelsen, of defending the rationality of law and the liberal ideal of formal justice via the rule of law. In his chapter on self-defence, Kammerhofer argues strongly against conceptions of self-defence employing flexible standards of legitimacy or reasonableness, contending that the test for any ‘special plea’ must be whether one would afford it to a state perceived as hostile, for example Iran or North Korea.Footnote 67 Whether intended or not, this has the effect of emphasizing the way that law, if universally applied, can promote reciprocity within international relations. Kammerhofer's style has the advantage, by focusing on legal validity and refusing to allow ‘fudging’ of positive law,Footnote 68 of casting serious doubt on self-interested functionalist claims as to what the law is. Indeed, there may be something useful in trying to withhold the title of ‘law’ from such claims and/or highlighting their status as non-law. But this only further suggests that Kammerhofer's intervention, like Kelsen's work, operates to promote particular liberal values, above all the rule of law.
3.2. Challenge surrounding insistence on the is/ought distinction
Kammerhofer's strong methodological stance, following Kelsen, that any approach which does not strictly abide by the norm/fact distinction fails to conceive of law as norms at all,Footnote 69 is open to challenge and unlikely to convince those of different theoretical persuasions. Leading Kelsen scholar Stanley Paulson has shown in some detail that the neo-Kantian transcendental argument, by which Kelsen attempts to justify his fundamental category of normative imputation (as distinct from factual causation) cannot work, and does not trap a sceptic who refuses to accept Kelsen's methodological stance.Footnote 70 For this reason, I think contemporary users of the Pure Theory should be wary of endorsing Kammerhofer's position that it is exclusively able to cognize law's normativity. Instead, one can accept, as Paulson and Lars Vinx have argued, that Kelsenian theory must compete with other legal theories that are also able to account for law's normativity without reducing it to factual causation, even if they are rooted in social fact (e.g. Hart).Footnote 71
There is much truth in Kammerhofer's related claim that legal theories cannot be falsified by facts, since legal theory determines its own object, meaning any inconvenient examples can be explained away as non-law.Footnote 72 Indeed, the Pure Theory's distancing of law from social fact can be useful in prompting us to think critically about the justification, in terms of formal legal validity, for views that may be routinely accepted. There is, however, a major downside to the Pure Theory's lack of emphasis on sociological factors. It is standard to expect legal theories, at a descriptive level, to help ‘explain the methods by which the existence and content of law are ascertained’.Footnote 73 Unsurprisingly, Kelsenian theory can seem distant from the concrete practices that occur in the name of law.Footnote 74
3.3. Challenge from realist perspectives on international relations
Following from the Pure Theory's lack of sociological grounding, the decision to focus on legal normativity in international relations can be challenged from more realist-inclined perspectives which see this as irresponsibly ignoring, and distorting our view of, political realities.Footnote 75 Anthony Carty, for example, argues that the Pure Theory ‘is a ticket for professional irresponsibility of the international lawyer in the face of political difficulties’.Footnote 76 Hedley Bull makes a similar criticism, complaining that ‘[t]he state . . . engaged both domestically and internationally in contests for power that take no account of law, is thus defined out of existence’.Footnote 77 Related critiques are made by two of Kelsen's most famous opponents: Hans Morgenthau and Carl Schmitt. For Morgenthau, legal validity depends upon whether the violation of an alleged rule is likely to be followed by a sanction, not upon whether the rule is validly enacted.Footnote 78 Schmitt is famous for maintaining that the sovereign, by deciding on the exception, always remains able to suspend the legal order and destroy legal normativity.Footnote 79 Such perspectives highlight a significant risk of Kelsenian formalism: it seems overly focused on legal validity and the realm of norms, and tells us little about contests of power that may end in displacement of the asserted law.Footnote 80 In practice, the powerful do sometimes move to set aside existing law, and actors do distinguish between what is likely to happen in a situation and what should happen according to formal law.Footnote 81
Notwithstanding the important insights offered by more realist perspectives, we may want to avoid solely thinking of law as a coercive order, subject to enforcement or displacement by the powerful.Footnote 82 Indeed, I think the two books under review teach us something useful precisely in their refusal to give up emphasizing legal validity in the face of factual power. For von Bernstorff, Kelsenian formalism, by emphasizing law's own distinct rationality, never reducible to power, can provide ‘self-critical distance toward the hegemonic instrumentalization of the notion of law in a given historical situation’.Footnote 83 Kammerhofer, discussing specific doctrinal controversies, repeatedly reminds us of the essential point that law is its own medium, structured by its own logic and that the powerful ‘are not always authorised to determine what is law . . . as it suits them’.Footnote 84 In short, both books highlight that there is important political work to be done in exposing the weaknesses of claims about positive international law we disagree with, particularly when faced with ‘charged legal interpretations’ put forward by powerful actors to justify their own actions.Footnote 85
True, we need to be cognizant that the powerful will retain the ability to act contrary to existing law, but, perhaps especially where this occurs, there seems little reason to give up legal validity as a potentially useful medium for critiquing their actions.Footnote 86 The massive protests heard against the second Iraq war, based on the invasion's illegality, are to my mind an example of this.Footnote 87 From this perspective, international law might operate, as Koskenniemi has suggested, as a carrier of an unachievable ‘regulative idea of universal community, independent of particular interests or desires’, used to challenge the ‘party rule’ of foreign policy and managerial governance.Footnote 88 The idea of international law as a medium for highlighting the ‘illegality of international reality’,Footnote 89 which is itself open to the criticism of lacking a sufficient basis in actual behaviour, is, of course, nothing new.Footnote 90 It is only one view of the relationship between international law and power, evoking a rather old-fashioned image of ‘speaking law to power’.Footnote 91 Of course it should be complemented by consideration of the many ways in which law can facilitate power,Footnote 92 and I will say something about this later when considering interpretive choice and legal realist-inspired challenges to Kelsen. My point here is that legal validity, heavily emphasized by both authors, can offer a useful medium for critiquing the actions of the powerful and should not be given up too quickly, even when confronted with the ability of the powerful to displace existing law.
4. Monism/dualism and the ‘choice hypothesis’
If there is a key contribution to international law that the Vienna school is remembered for, it is, as von Bernstorff argues, the view of law as a monistic whole, with international law sitting above, and explaining the validity of, state legal orders.Footnote 93 Kelsen has been subject to important criticism in this area,Footnote 94 and I will not examine all his views. Rather, I will argue that the two books under review, while not endorsing his views on the interaction of international and domestic law as a whole,Footnote 95 share his perspective of an international law elevated above states, that is itself sovereign.Footnote 96 For Kelsen, since there was no third order sitting above and co-ordinating national and international law, the two ‘must be in a relationship of superiority and inferiority’.Footnote 97 Kelsen held that any ‘pluralistic’ position which sought to uphold the mutual independence of national and international law was inconsistent and had to end in the claim that one's national legal order was sovereign and international law was only valid as subordinate, delegated national law.Footnote 98 Kelsen accepted that the latter claim was theoretically consistent and a possible construction, commenting that ‘to recognise the social order of one's own group as being the only true “law” is a typically primitive view’.Footnote 99 Like the basic norm, Kelsen saw this initial decision, regarding which legal order is superior, as an a priori, pre-legal assumption.
Von Bernstorff, in his book, makes quite a lot of the ‘choice hypothesis’, arguing that paradoxically Kelsen, while trying to expel the political, had, in this idea, ‘generated . . . a far reaching concession that legal cognition in international law at its basis was also subjective and political in character’.Footnote 100 However, if Kelsen's project is understood not as ‘objective’ but as resting on certain liberal views – above all prioritizing the rule of law within international relations – then the ‘choice hypothesis’ will not count as a concession. Rather, as von Bernstorff notes, it will simply reflect that each interpreter faces an important political choice of whether to work from an ascending or descending perspective when thinking about international relations.Footnote 101 While there may be good arguments for choosing one view or another, ultimately each interpreter must make their own choice.Footnote 102
As will already be apparent, both books under review make clear their choice in favour of a binding international law sitting above states. von Bernstorff, as discussed, sees Kelsen's defence of a specific legal rationality as valuable, providing a means for resisting the instrumentalization of law by hegemonic actors.Footnote 103 Kammerhofer, in launching a fundamental attack on the idea that subsequent practice can modify treaty norms, invokes the classic Kelsenian argument that states can only create international law ‘because there is a legal order authorising them to create law’.Footnote 104 Thus states do not have ‘natural or inherent power[s] . . . The only true sovereign in international law is international law itself’.Footnote 105 Obviously, this will not satisfy those who see state sovereignty as a reality that always threatens the bindingness of international law and I have tried to address this view above.Footnote 106 This more realist perspective, however, may just represent the other side of the ‘choice hypothesis’, namely a view that states are ultimately sovereign and international law is much more marginal than Kelsen suggests, always subject to state will.
5. Kelsenian-style interpretation: indeterminacy as highly significant but not unlimited
I have argued that the two authors under review, in their different styles, capture something valuable in thinking of international law as its own medium, influenced by, but never reducible to, other, external rationalities.Footnote 107 That both authors can be interpreted as taking this position seems to reflect their views on indeterminacy: as I will outline, for both von Bernstorff and Kammerhofer, although interpretation typically involves choice, meaning there is no ‘right’ answer, indeterminacy can ultimately be contained,Footnote 108 so that there remains a distinctly legal methodFootnote 109 and certain interpretations can be excluded as unjustifiable. In contrast, for those who hold that indeterminacy is completely pervasive, a Kelsenian approach, and its suggestion that there remains any distinct legal medium, will be unacceptable. Clearly, I will only be able to touch on a much broader debate about the extent of indeterminacy in international law. My purpose is simply to highlight that the two authors’ common view of international law as a distinct medium, capable of ensuring a degree of formal justice, seems to depend on a belief which will be shared by some but not others that indeterminacy can ultimately be contained.
In taking the position that indeterminacy is highly significant and needs to be acknowledged, but is, ultimately, limited, both books follow Kelsen's views on interpretation. For Kelsen ‘the norm to be applied is simply a frame within which various possibilities for application are given and every act that stays within this frame . . . is in conformity with the norm’.Footnote 110 Accordingly, interpretation ‘leads not necessarily to . . . [one] correct decision, but possibly to a number of decisions, all of them of equal standing’.Footnote 111 Where a judge is authorized to make a binding interpretation, he or she is able to choose to fix a single one of these potentially multiple possible meanings as positive law.Footnote 112 Kelsen accepted that such judicial choice was not determined by positive law,Footnote 113 and would be influenced by non-legal norms such as morality and justice.Footnote 114 Hence, judges in applying higher norms create law, as legislators do, but their discretion is more limited.Footnote 115
Like Kelsen, both of the books under review explicitly confront interpretational choice, emphasizing its importance but also holding that it is not unlimited, so that there remains a meaningful distinction between judicial decisions and the less restrained discretion of a legislator.Footnote 116 Von Bernstroff, in a chapter dealing with Kelsen's proposals for compulsory international adjudication, examines in some detail the criticism that the discretion inherent in interpretation, as acknowledged by Kelsen, land us with a ‘gouvernement des juges’.Footnote 117 Von Bernstroff argues that this criticism ‘fail[s] to consider the specific legal rationality inherent in judicial proceedings, which sets it apart from a purely political organ’, referring to the ‘juristic argumentation’ involved in legal decision-making and the fact that judges are appointed and trained in a different way to politicians.Footnote 118 Clearly, what constitutes convincing argument in juristic discourses differs from that in overtly political discourses – as von Bernstorff emphasizes, juristic argument is expected to constantly engage with an existing legal corpus.Footnote 119 However, this response is not wholly convincing, as judicial decision-making, on Kelsen's own account, still ‘involves sometimes intensely political exercises of judicial discretion’, that are not constrained by existing law.Footnote 120 Indeed, von Bernstorff seems less than fully convinced that Kelsen's theory can overcome this difficulty, asking very pertinently, in the Postscript: ‘how does the law fulfil its function of creating order [in a pluralistic world of values] if its application remains, in final analysis, political?’Footnote 121 Von Bernstorff finishes his treatment of this issue in the Postscript acknowledging: ‘it remains problematic . . .. that the Pure Theory . . . promotes the civilizational function of a specific judicial rationality without being able to explain it.’Footnote 122
Kammerhofer, in his more detailed, doctrinally focused style, puts considerable effort into highlighting the choice inherent in interpretation, casting the Pure Theory as a ‘tool for the deconstruction of traditional international legal doctrine’, because it highlights the uncertainty inherent in interpretation, ‘that can only be filled by adding external elements to positive international law’.Footnote 123 Kammerhofer's chapter on interpretation, like his whole book, provocatively deconstructs numerous mainstream understandings, revealing them to often be based on little more than unreflective assumption.Footnote 124 Yet Kammerhofer, like Kelsen and von Bernstorff, sees the potential meanings of norms as limited, so that some positions will not qualify as justifiable interpretations. For example, Kammerhofer argues that the ICJ's interpretation of Article 27(3) of the UN Charter in the Namibia Advisory Opinion – that abstention by a permanent member in a Security Council vote does not signify a vetoFootnote 125 – does not fall within the frame of possible meaning and is a modification rather than application of the norm.Footnote 126
Another, more critical, perspective would insist that because of the possibility of appealing to the underlying purposes of rules, or choosing between various rules and exceptions, in practice any course of action will be able to be defended by ‘impeccable legal arguments’.Footnote 127 From this perspective, credible legal argument will always be able to produce inconsistent or divergent results and remain reversible.Footnote 128 If one is fully committed to these claims then the idea of any convincing restrictions on interpretation, and a distinct legal medium, would seem objectionable. Others, in contrast, will sympathize with the position of the two books reviewed: of course judges make law too, but judicial decision-making is constrained by having to engage with the legal past and give reasons, so not any position will be justifiable.Footnote 129 Ultimately, this debate may be one of degree,Footnote 130 and is more meaningfully undertaken with reference to specific interpretive controversies.Footnote 131 I have simply highlighted that the two books appear to work within a premise of legal interpretation as an ultimately constrained act of choice, which will be shared by some and for those of a more critical persuasion appear quite artificial.
6. Conclusion
Kelsen is for some a systematic theorist of ongoing relevance, for many others he appears dogmatic and outdated.Footnote 132 The reality probably lies somewhere in between these claims. I have considered several important criticisms of Kelsen and acknowledged the truth in them. The risk involved in abstracting away from the world of facts in the international sphere, where law is often liable to being set aside by the powerful, seems particularly significant. But my central point is that the two books under review highlight an aspect of Kelsen's thought that may be worth holding on to: namely that law does not seem wholly reducible to other external rationalities, and an insistence on legal validity and a non-instrumental view of law can sometimes promote a modicum of formal justice in international relations. This aspect of Kelsen's thought is reflective of the distinctly liberal orientation of his work, above all the idea that something resembling the rule of law can be promoted in international relations despite conditions of value pluralism. Even those who are sceptical or actively opposed to this premise will find rich, impressively researched and thought-provoking discussions in the two books reviewed. Going forward they suggest two quite different and potentially complementary styles of international legal scholarship: Kammerhofer's book demonstrates the value of exploring in detail particular interpretive controversies while making our legal-theoretical choices explicit; von Bernstorff's book highlights the value of contextualizing the ideas of our intellectual predecessors in reflecting on how we might choose to argue today.
