The orthodox theories of customary international law have resolved the dichotomy between the voluntarist and intellectualist camps into a synthesis. While they do not recognise pre-existing law as the basis of customary international law, they also do not approximate it to an unwritten agreement. Traditionally the elements of ‘consent’ and ‘opinio iuris’ (as true belief) are seen as irreconcilable antagonists.
Modern theories tend to smudge the two extreme notions into a quasi-synthesis.
The key to this smudging is the tendency towards the inclusion of an act of will within their notion of the subjective element of customary law-making. It is an acknowledgement of the constitutive function of opinio iuris. This smudging, however, leads to further uncertainty and that is a direct result of not distinguish- ing between ‘will’ and ‘belief’. The difference between the two concepts becomes unclear: can one say that a belief, especially if formulated as belief that a practice ought to be law, is not an act of will? Also, is the ‘belief that something is law’ really an act of will? We will return to this, one of the key questions of all customary norm-making, presently.
The orthodox opinio iuris paradox, on the other hand, is a slightly different problem. As mentioned above, the question there is how the belief of the subjects of law can be true that something is law when it is by definition not yet law, but is only just being created. Two reasons make a solution to that problem – that there needs to be a mistaken belief in law where there is none – no longer quite as unattractive. The first reason is pragmatic, for the epistemic uncertainties of customary international law provide support to the orthodoxy. Because of our poor epistemic position vis-à-vis the elements of custom-creation and their evidence
102 Walden (1978) supra note 2 at 97.
103 Thirlway (1972) supra note 26 at 55.
104 D’Amato (1971) supra note 15 at 194; Koskenniemi (1989, 2005) supra note 47 at 374–375 (423).
105 Human beings do not have a collective consciousness.
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(Section 3.2.2), it is virtually impossible to distinguish between what the law is and what it ought to be.106 One would have to know what the law is in order to be able to distinguish between the lex lata and lex ferenda in the first place. The object of ascertaining the opinio iuris is to find out what the law is and that is what has to be proven. Due to this large measure of uncertainty, it is difficult to tell when a norm of customary law has emerged. Thus, if a state believes some norm to be valid customary international law, it has no means of knowing whether this belief is true – i.e. whether the norm believed in is valid (in ‘existence’). States are not in a position to know whether the proposed norm they are championing has actually become law. The ‘mistake’ involved in the opinio iuris paradox is no longer clear nor ‘necessary’ and the constitutive function of states’ beliefs comes to the fore.107
The constitutive function of the subjective element is the second tactic to lessen the impact of the traditional paradox. Because the subjective element does not have to correspond to some pre-existing legal ‘reality’, i.e. the claims made do not have to be truthful, but are themselves constitutive of customary law, it is the fact that the claim is made, not the value of the claim that is relevant. A constitutive view of opinio iuris requires that the veracity of the beliefs be secondary to the existence of the belief. Bruno Simma has argued thus as early as 1970:
Kelsen, for example, had earlier [1939] held that this theory is nothing but ‘évidemment fausse’, because it is founded on an error, nay, on a logical contradiction . . . This charge is unfounded. The orthodox theory could only then be found logically contradictory, if it were to postulate the validity of a norm with the same content as condition for the creation of customary law. However, it only demands that the states creating customary law believe that such a norm is valid, that they thus act in error.108
The orthodox synthesis may thus involve making an error of judgment into a condition for the creation of customary law; ‘error [is] the father of a customary law’.109 If that is so – and it is doubtful whether a mistake need necessarily be
106 Koskenniemi (1989, 2005) supra note 47 at 375 (424).
107 In a sense this was discussed by Walden (1978) supra note 2, reinterpreting the ‘internal aspect’ of rules developed by Herbert Hart (H.L.A. Hart, The concept of law (1961) 55–56, 86–88).
108 ‘So vertrat etwa Kelsen frỹher [1939] die Meinung, daò diese Lehre nichts weniger als
“évidemment fausse” sei, weil sie auf Irrtum, ja auf einem logischen Widerspruch basiere . . . Dieser Vorwurf ist aber unberechtigt. Logisch widersprỹchlich wọre die herrschende Lehre nọmlich nur, wenn sie zur Entstehung einer Norm des Vửlkergewohnheitsrechts die Voraus- setzung aufstellen wỹrde, daò eine Norm desselben Inhalts bereits gilt. Sie fordert aber lediglich, daò die Staaten, die das Gewohnheitsrecht zur Entstehung bringen, glauben, daò eine derartige Norm gilt, daò sie also im Rechtsirrtum ỹben.’ Bruno Simma, Das Rezipro- zitọtselement in der Entstehung des Vửlkergewohnheitsrechts (1970) 34 (FN 77) (emphasis on name removed).
109 ‘der Irrtum [ist] der Vater eines Gewohnheitsrechts’; Carl Schmitt, Der Hüter der Verfassung (1931) 126, citing: Richard Thoma, Der Vorbehalt des Gesetzes im preuòischen Verfas- sungsrecht, in: Festgabe für Otto Mayer. Zum siebzigsten Geburtstag dargebracht von Freunden, Verehrern und Schỹlern, 29. Mọrz 1916 (1916) 165–221 at 213.
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made – it might well violate our sense of aesthetics, but there are no a priori reasons why this should not be a method of making law. Orthodoxy does not demand ‘that existence [of law] is made a condition for [its] creation’,110 but rather that the existence of the belief is made a condition for the validity of customary international law. The difference is the essence of the constitutive function – its presence, not its content is the decisive factor in the creation of law. The truth-value of the belief is irrelevant, because the subjective element in no case requires knowledge as true belief,111 but – at best – belief, i.e. the presence of a conviction that p is prescribed.
This paradox is soluble, hence not a paradox at all; here we do not face a problem.
However, this freedom from one paradox costs us dearly, for we immediately stumble into another paradox which cannot be resolved so easily. This paradox becomes obvious if we do not accept pragmatic smudging so easily (cf. Section 5.4) and if we try to apply a pure theory of law, one that manages to explain both international law’s normativity and its positivity. A theory that attempts to do so must face, inter alia, Martti Koskenniemi’s critique,112 or at least the part not resolved by the distinction in Section 3.2.5, which is an attempt to show that no such reconciliation is possible. Such an attempt will also show the critical force of the Pure Theory of Law vis-à-vis orthodox conceptions of doctrine113 by consistently applying the positive normative order.
The ‘new opinio iuris paradox’ follows from opinio’s constitutive function. Hans Kelsen and his followers have always had a problem in fitting customary law into a positivist framework. How can customary norm-creation be reconciled with customary law’s status as positive law? The ‘positivity problem’ of the subjective element is caused by the very idea of (the Pure Theory’s) positivism, which requires human-willed activity to recognise a norm as positive. Only if a norm is the ‘sense of an act of will’114 can it be called a ‘positive norm’ and all other norms are fictional (see Section 6.2.2). Since the objective element – practice – by defin- ition cannot contain will, but consists of factual patterns, the subjective element needs to contain an act of will in order for customary international law to be able to exist as positive norms. Customary international law, however, seems to be unintentional, undirected and unwilled human activity.115
This strict requirement of an ‘act of will’ has led a number of scholars to criticise Kelsen’s theory. Herbert Günther, while in other respects agreeing with the Pure Theory, believes that the postulate adopted necessitates an artificial
110 Hoof (1983) supra note 10 at 93 (emphasis added).
111 Peter Baumann, Erkenntnistheorie (2002) 36–37.
112 In particular: Koskenniemi (1989, 2005) supra note 47.
113 Clemens Jabloner, Kein Imperativ ohne Imperator. Anmerkungen zu einer These Kelsens, in:
Robert Walter (ed.), Untersuchungen zur Reinen Rechtslehre II. Ergebnisse eines Wiener Rechtstheoretischen Seminars 1988 (1988) 75–95 at 87.
114 Kelsen (1979) supra note 46 at 4 (Ch 1 VIII), 221 (N 1): ‘Sinn eines Willensaktes’. ‘Sinn’ could also be translated as signifying ‘meaning’.
115 Kelsen (1952) supra note 83 at 308.
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search for an act of will within the customary process.116 He thinks that this is the result of the methodological mistake on Kelsen’s part of drawing an illegitimate analogy from municipal law to international law. He alleges that this constitutes a narrowing of the very concept of ‘positive law’; it seems wrong to conclude from law’s positivity that it needs to be enacted in a formal and goal-orientated manner.
For Günther, positivity ought ‘to be understood as a property only of norms, only of those norms, which . . . were in some way “man-made”, whose content was determined by a human act’.117 Yet the real problem lies elsewhere, as Koskenniemi points out:
The psychological element might either be: 1) the belief or conviction that something is law; 2) the will of the State that something be law. The opinio might be understood as pertaining to what the State knows or believes or it might be thought of as a voluntas, a conscious, law-creating will. . . . They are not merely different, but mutually exclusive and defined by this exclusion.118
How, indeed, can a belief (opinion, statement) be a will? That is the question and that is the new paradox. When ‘men do not necessarily know that they create by their conduct a rule of law, nor do they necessarily intend to create law’,119 this creation is automatic, and customary norms would be based on an Is alone, which is a breach of the dichotomy of Is and Ought.
Koskenniemi’s critique unfortunately acts as a distraction, for he may have chosen a different category in identifying the crux. He argues that the orthodox synthesis holds ‘the psychological element as partly an object of knowledge, partly an object of will’,120 because the opinio iuris is belief, not knowledge, It has thus not, as he claims, an ‘existence independent from the process of knowing’121 and opinio iuris therefore is not bound up with the ‘extra-voluntary reality’;122 it simply is independent of the existence of the object of the belief.
Does not the belief contain the will to create the norm in some form? Kelsen is silent on the details of the will that is necessary. Is it the will to create norms? Is the positive norm as the sense (meaning) of an act of will created by the specific form or content of the sense of the act of will? Could we not say that the act of will need not be a specific will to create a norm, but can also be a belief that implicitly accepts that a norm may be created, in analogy to dolus eventualis in criminal law?
Would it not be possible to argue that an unspecific will is contained in the belief ?
116 Günther (1970) supra note 40 at 81–83.
117 ‘demnach als Eigenschaft verstanden werden, die ausschlieòlich Rechtsnormen und darunter nur denjenigen zukommt, die . . . in irgendeiner Weise “man-made” sind, ihren Inhalt durch einen von Menschen sich herleitenden Kreationsakt empfangen haben.’ Günther (1970) supra note 40 at 83.
118 Koskenniemi (1989, 2005) supra note 47 at 369–370 (417–418) (emphasis added).
119 Kelsen (1952) supra note 83 at 308 (emphasis added).
120 Koskenniemi (1989, 2005) supra note 47 at 373–374 (422).
121 Koskenniemi (1989, 2005) supra note 47 at 374 (422).
122 Koskenniemi (1989, 2005) supra note 47 at 374 (422).
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Hans Kelsen’s own arguments on customary law and its subjective element seek to reconcile the problem of will and belief in this fashion. For him ‘custom is, just like a legislative act, a mode for creating law’.123 Both enactment of a statute and the customary process represent acts of will, but are merely different ways of manifesting that will. He explains the change from belief to will thus:
Only when these acts [the practice] have been occurring for a certain amount of time, the idea develops in an individual that it ought to behave, as the members of the society usually behave, and the will that other members of society ought to behave in this manner. . . . Thus custom becomes a collective will, whose subjective sense is an Ought.124
The concept of a collective act of will – however much its possibility may be in doubt125 – is not the real issue. A better reading of the Pure Theory’s customary theory is that the will that subjects of law ought to observe the factual pattern has become a collective, but not a ‘legislative’ will. Norms resulting from the customary process are positive norms by virtue of that collective will (opinio iuris).126
For Clemens Jabloner, the weakness of the doctrinal arguments brings the Pure Theory’s critical side to the fore. If customary international law cannot fulfil the strict criteria for positivity, then customary international law simply is not positive law.127 A consistent theory relentlessly cuts through long-established doctrinal constructs which ultimately are flawed. The distinction between ‘legisla- tive’ and ‘customary’ acts of will is enticing, but it cannot satisfactorily explain away the chasm between ‘belief’ and ‘will’. Either the customary process cannot even abstractly work to make norms – which would mean that customary inter- national law cannot be a source of international law – or the conception of opinio iuris as belief is wrong and the subjective element needs to be an act of will properly speaking. Either possibility makes unintentional and unwilled inter- national law-making impossible. The point here is not that orthodox doctrine is incommensurate with a particular scholar’s ideas, but that it is incommensurate
123 ‘la coutume est, tout comme l’acte législatif, un mode de création du droit’; Kelsen (1939) supra note 12 at 259; Kelsen (1979) supra note 46 at 113–114 (Ch 34 III).
124 ‘Erst wenn diese Akte [der usus] durch eine gewisse Zeit erfolgt sind, entsteht in dem einzelnen Individuum die Vorstellung, daò es sich so verhalten soll, wie sich die Gemeinschaftsmit- glieder zu verhalten pflegen, und der Wille, daò sich auch die anderen Gemeinschaftsmitglieder so verhalten sollen. . . . So wird der Tatbestand der Gewohnheit zu einem kollektiven Willen, dessen subjektiver Sinn ein Sollen ist.’ Kelsen (1960) supra note 69 at 9 (Ch 4 b) (emphasis added);
Hans Kelsen, Was ist juristischer Positivismus?, 20 Juristen-Zeitung (1965) 465–469, reprinted in:
Hans Klecatsky, René Marcic, Herbert Schambeck (eds), Die Wiener rechtstheoretische Schule.
Ausgewọhlte Schriften von Hans Kelsen, Adolf Julius Merkl, Alfred Verdross (1968) 941–953 at 944.
125 Ota Weinberger, Normentheorie als Grundlage der Jurisprudenz und Ethik. Eine Auseinanderset- zung mit Hans Kelsens Theorie der Normen (1981) 28–30; Jabloner (1988) supra note 113 at 87.
126 Kelsen (1960) supra note 69 at 9 (Ch 4 b).
127 Kelsen (1960) supra note 69 at 232 (Ch 35 b).
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with international law’s nature as a positive normative order. Thus we are left with this paradox as a dangerous manifestation of uncertainty in customary international law.
3.4 Desuetudo in customary law – how do customary norms die?
Desuetude is a rarely discussed problem of the customary process. Can customary international legal norms fall into desuetude and lose their validity? It seems generally accepted, though one may doubt this (Section 5.3), that customary norms can be derogated from by another norm of the same kind, i.e. another customary norm. We are not concerned here with the replacement of norms by norms, but with their desuetude:
[A] single norm or a normative order as a whole lose their validity when they lose their effectiveness or the possibility of their effectiveness; as far as general norms are concerned: when they stop being generally observed and if not observed, being applied.128
If we apply this mode of losing validity to customary international law, the question can be reformulated. Once a norm of customary law is established, does it need to be continuously supported by practice and opinio iuris or only by one element to remain customary law? The first position could be called ‘statist’ or ‘establishment’
theory. Once established, a norm of customary law continues to exist until a new norm has come into existence in accordance with the rules of custom-formation or it is derogated from by a new norm.129 A norm no longer supported by any practice or opinio iuris remains valid unless there is practice and opinio iuris sufficient to create a norm to supersede it. The second theory might be termed ‘dynamic’ or
‘upholder’ theory. Custom is upheld by the continued presence of its constituent elements and as soon as it is not upheld in this manner, it falls into desuetude and ceases to be a norm.130 If states behave differently and believe differently to the established norm, the old norm is suddenly no longer valid, even if this trend is not yet a new customary norm.
Neither position necessarily implies that the effectiveness of a norm is its valid- ity. Kelsen, who espoused the second, ‘dynamic’, option as a matter of general normative theory, saw effectiveness not as a basis for the validity of laws, but as a
128 ‘[E]ine einzelne Norm und eine ganze normative Ordnung ihre Geltung verlieren, aufhửren zu gelten, wenn sie ihre Wirksamkeit oder die Mửglichkeit einer Wirksamkeit verlieren; soweit generelle Normen in Betracht kommen: wenn sie aufhửren im groòen und ganzen befolgt, und wenn nicht befolgt, aufhửren angewendet zu werden.’ Kelsen (1979) supra note 46 at 112–113 (Ch 34 II).
129 Bernhardt (1992) supra note 40 at 901.
130 Bos (1982) supra note 15 at 15–16; Robert Kolb, Selected problems in the theory of customary international law, 50 Netherlands International Law Review (2003) 119–150 at 140–141;
Thirlway (1972) supra note 26 at 56; Villiger (1997) supra note 4 at 55.
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condition for losing its validity.131 What are the logical possibilities? On the one hand, desuetude could be a logically necessary collorary of all normative systems.
Without positive regulation within a particular normative order, any norm could lose validity if it becomes utterly ineffective. However, the very idea of pre-positive desuetude is inconsistent with a positivist normative theory, because only norms can change norms. On the other hand, a norm of positive international law which specifies that ‘ineffective norms are no longer norms’ could be valid. The second possibility raises the question of proving such a positive norm and of the effect of such a derogating norm (Chapter 5).
131 Kelsen (1979) supra note 46 at 112 (Ch 34 II): ‘Because the effectiveness of a norm is constituted by its general observance and by its application in cases of non-observance, its validity, however, is that it ought to be observed and [that it ought to be] applied in cases of non-observance, the validity has to be divorced from the norm’s effectiveness as an Ought from the Is . . . effectiveness is a condition for validity.’ ‘Da die Wirksamkeit einer Norm darin besteht, daò sie im groòen und ganzen tatsọchlich befolgt und wenn nicht befolgt, im groòen und ganzen angewendet wird, ihre Geltung aber darin, daò sie befolgt oder wenn nicht befolgt angewendet werden soll, muò die Geltung von der Wirksamkeit der Norm als ein Sollen von einem Sein geschieden werden. . . . Wirksamkeit ist eine Bedingung der Geltung.’
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