A widely held but problematic view holds that orthodox customary law theory leads to the conclusion that change in customary international law is not possible, because the practice that seeks to establish a diverging norm must necessarily be a violation of the previously established norm. It is argued that since ‘this line of reasoning . . . runs counter to the maxim ex iniuria jus non oritur’ law cannot be formed in this way. ‘It must be an extraordinary system of law which incor- porates as its main, if not the only, vehicle for change the violation of its own provisions.’74
The peculiarity of this mode of creating law is that it partially depends for its creation upon behaviour which can be seen both as application and as creation of law; its norms are created in part by acts which are also an application of the resultant norm. It is the very idea of customary law that factual behaviour patterns of the subjects of law (customs) count as building-blocks for law-making, irrespective of their legality. Those who adopt the ‘narrow’ view of state practice (Section 3.2.1) see this distinction more sharply than those who prefer the second option. Let us assume, for example, that most subjects wear a red hat. They also
73 Kelsen talks about four functions of norms: prescription, permission, authorisation, derogation.
Kelsen (1979) supra note 46 at 76–92 (Chs 25–27). In a 1962 paper, he acknowledges that ‘[t]he derogating norm, however, cannot be established by custom’ (Hans Kelsen, Derogation, in: Ralph A. Newman (ed.), Essays in jurisprudence in honor of Roscoe Pound (1962) 339–355 at 343;
Kelsen (1979) supra note 46 at 87 (Ch 27 V)).
74 Hoof (1983) supra note 10 at 99.
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believe that the law obligates wearing a red hat. The first element becomes the content of the obligation. The same act makes the law and can be subsumed under the law. Wearing a red hat creates the ‘red hat norm’, but as soon as the red hat norm is valid, the act of wearing of a red hat (or of not wearing one) is a question of the application of the red hat norm. If one were to distinguish legal and illegal behaviour and only legal behaviour could be counted as state practice, then customary law could not change.
The maxim ex iniuria ius non oritur is breached only if the law (e.g. the ‘red hat norm’) can solely be changed by the puissance of facts which constitute a violation of the law. The difference here is that the meta-law on customary law creation requires practice for the creation of new customary law. This can possibly lead to the confusion of two separate norms. On the one hand we have a substantive norm; on the other hand there is the meta-norm on custom-creation. The creation and the application of norms are two different functions which may be united in the same process. The creation of law is at the same time the application of the meta-law on law creation. In contrast, the application of the norm created under the meta-law to concrete human behaviour may or may not involve further norm-creation. If a court is competent to sanction violations of the red hat norm, it applies that norm (together with procedural and other norms) to create an individual judgment sanctioning an offender.
In our case, this amounts to a dédoublement fonctionnel of factual behaviour. Mr X wears a green hat. As the application of the ‘red hat norm’, it is a violation. As the application of the ‘change in customary law’ norm, it is a building block for a possible new norm. After the red hat norm has become valid, Mr X’s acts of practice are an application of the red hat norm and, if they break the red hat norm, they are violations of the red hat norm. Yet, they are not disqualified from constituting the building blocks of a different ‘green hat norm’. Once the event horizon of the green hat norm is crossed, it becomes law. Deviating instances between the coming-into-existence of the red hat norm and the green hat norm remain violations of the red hat norm. Why could usage which violates law not be eligible as state practice? Customs as mere behavioural regularities have no
‘legality’ for their purpose as building blocks of new law. Human behaviour has two meanings, given to it by two different norms. The legal consequences of the two norms might be considered incompatible, but only from a political or practical, not from a logical or normative point of view. There is no logical contradiction in saying that wearing a green hat is to be punished and that it is part of law-making at the same time. There is no contradiction partly because there are two norms at work here.75
This is not the only question that can be asked with respect to the possibility of change in a normative order. Later on (Section 5.3) we will probe further into the concept of ‘change’ in connection with the discussion of the (apparently
75 For a more precise formulation of the relationship between the application and creation of law see Kelsen (1960) supra note 69 at 240 (Ch 35 f).
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self-evident) lex posterior maxim. This topic is much better placed in the chapter on norm-conflicts and the arguments brought to bear there do not influence the non- contradictoriness of the relationship between creative and applicative behaviour portrayed supra.
3.3 Opinio iuris
The concept of opinio iuris is the centrepiece of the conception of customary law.
It may be the most disputed and least comprehended component of the workings of customary international law. At the heart of the debate lies an important conflict. On the one hand, customary law-making seems by nature indirect and unintentional. On the other hand, the creation of positive norms requires an act of will. In the international legal system, great value has traditionally been placed on the states’ agreement or consent to create obligations binding upon them; ‘no state can be bound without its will’ might be a typical statement.
Whether that is indeed the real requirement is debatable, but it is certain that one of the core uncertainties of any doctrine of customary international law is the problem of reconciling the customary nature of customary law with its positivity (Section 3.3.3).
The ascendancy of the opinio iuris theory is an interesting development. Earlier surveys of the literature on customary law had included many other theories which radically differed from the subjective element as it is understood now.76 It is true that nowadays the opinio iuris theory is neither clearly defined nor the only interpretation of the subjective element,77 but while it used to be just one theory among others, it has advanced to the status of orthodoxy, a standard which all concurrent theories are measured against.78
Within the complex of problems associated with the subjective element, the first and elemental question to be solved is the nature of opinio iuris: what exactly is it; what is it meant to represent? Is it a necessary or a contingent ingredient of customary law-making? The uncertainty on this point influences many other problems associated with the subjective element, just as the question of the nature of state practice decides many questions commonly asked in connection with the objective element. This section will expose the breadth of opinions in today’s discussions of customary international law.
For this exposition to work properly it is necessary to assume, just for a few paragraphs, that orthodox opinio iuris theory is not orthodox at all. For an
76 Günther (1970) supra note 40 at 15–58, 149–154; Kirchner (1989) supra note 3; R. Fidelio Unger, Vửlkergewohnheitsrecht – objektives Recht oder Geflecht bilateraler Beziehungen: Seine Bedeutung für einen ‘persistent objector’ (1978).
77 For a reinterpretation of opinio iuris see: Anthea Elizabeth Roberts, Traditional and modern approaches to customary international law, 95 American Journal of International Law (2001) 757–791.
78 David P. Fidler, Challenging the classical concept of custom: Perspectives on the future of custom- ary international law, 39 German Yearbook of International Law (1996) 198–248.
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understanding of the fundamental questions – and for an understanding of the subtle differences of opinion within orthodoxy – we need to analyse the nature of the subjective element on a level playing field, without giving preference to ortho- doxy as it now stands. This can be achieved by counterposing two somewhat polarised concepts, namely that of ‘voluntarism’ and the ‘opinio iuris approach’79 – discussing their merits and demerits – and by subsequently clouding the strict dichotomy by loosening the strictures of the theoretical models. We will thus find the thesis of consent (Section 3.3.1), the antithesis of opinio as true belief (Section 3.3.2) and the apparent synthesis of the orthodox opinio iuris theory (Section 3.3.3).
All of these have their own theoretical, philosophical and ideological foundations, which will largely be left aside in this chapter. The theoretical ‘justification’ for source-law will be discussed in Section 6.2.