4 Interpretation and modi fi cation
6.1 What is a ‘source’ of international law?
6.1.2 The nature of the sources of international law
Before we continue to discuss the views of the theoretical basis or justification for sources, it might be worth discussing the ‘nature’ of the meta-norms on inter- national law-creation. What is meant by this term? Alf Ross identifies a problem with the idea of sources as commonly conceived, for:
the doctrine of the sources can never in principle rest on precepts contained in one among the legal sources the existence of which the doctrine itself was meant to prove.
The basis of the doctrine of legal sources is in all cases actual practice and that alone.34 That would mean that customary international law could not be the source for customary international law, because it would in this case be based on itself. The question of what Rechtsform these meta-norms of law-creation take might be con- sidered secondary. It is important, however, for international legal scholarship to know where one might find the laws on law-creation; that, in turn, depends on the form of these meta-laws. If law is an ontology of norms, we can describe the Rechtsform (Section 5.5.2) as the phenomena the norms manifest themselves.35 Taking customary international law as an example, the question is answered in different ways.
(1) Some scholars contend that norms on the making of customary inter- national law are themselves customary international law. Herman Meijers and Raphael Walden transpose Herbert Hart’s idea of secondary rules to inter- national law:36 international law’s secondary rules of law-creation are customary rules.37 Gennady Danilenko ascribes to Kelsen the view that ‘a positive customary rule cannot determine custom as a law-creating procedure’.38 In the work cited by Danilenko, however, Kelsen does not support that view:
34 Ross (1947) supra note 26 at 83.
35 Cf. Wolfram Karl, Vertrag und spọtere Praxis im Vửlkerrecht (1983) 38: ‘This view, however, is based on a very narrow conception of [legal] science and reduces the theory of law to a mere theory of the forms the law takes. It has been overcome, because even the “new Vienna School [of Jurisprudence]” (starting with Nawiasky) has rediscovered the purpose of law and adds a theory on the substance of law to the theory of the forms of law.’ ‘Doch ist diese Auffassung, die einem besonders engem Wissenschaftsbegriff entsprang und die Rechtslehre auf eine bloòe Rechts- formenlehre beschrọnkte, heute ỹberwunden, da selbst eine “neuere Wiener Schule” (aufbauend auf Nawiasky) den Zweck im Recht und in der Rechtsnorm neu entdeckt hat und der Rechtsfor- menlehre eine Rechtsinhaltslehre an die Seite stellt.’
36 Herman Meijers, How is international law made? – The stages of growth of international law and the use of its customary rules, 9 Netherlands Yearbook of International Law 1978 (1979) 3–26 at 3 (FN 1): ‘These constitutive requirements [for the making of treaty and customary law] are them- selves also rules of treaty law and customary law.’; Raphael M. Walden, Customary international law: A jurisprudential analysis, 13 Israel Law Review (1978) 86–102 at 88 et seq. In contradistinc- tion see H.L.A. Hart, The concept of law (1961) 208–231 (Ch X).
37 The specifics of Hart’s theory and its espousal by international lawyers will be discussed below (Section 6.2.2).
38 Gennady M. Danilenko, The theory of international customary law, 31 German Yearbook of International Law (1988) 9–47 at 17.
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[I]f the constitution of a legal community was not created by legislation, but by way of custom . . . This situation cannot be seen as the constitution which has been created by custom, that is [a] positive [constitution], empowering custom as law-making actus reus.
That would be a petitio principii. If the positive constitution . . . can be created by custom one must presuppose that custom is a law-making actus reus.39
Kelsen is arguing that the contention is a petitio principii40 only if the constitution is itself customary law. Because the constitution would already be made up of customary law, customary law would already be included among the sources of law before one got to a subordinate source called ‘customary law’. Yet here we face two objections. One is mentioned by Alf Ross in the quotation given above and refers to the apparent vicious circle in basing customary international law on itself. This is a problematic conclusion, for the form a norm takes is irrelevant for its position in the hierarchy of validity. As already demonstrated, a form can take multiple points in the hierarchy (Section 5.5.2) – in Austrian constitutional law a statute in part regulates the creation of statutes and constitutional statutes. The objection raised by Ross may not be directed against this specific point, but his theory of law requires all Ought to be reduced to Is. Being a form of legal realism, his theory needs to base norms on facts alone: the basis ‘is in all cases actual practice and that alone’.41 Ross does not allow for a Grundnorm as restatement of the dichotomy of Is and Ought, because this concept is at its core an expression of idealism which cannot find a place in this theory. Consequently, norms cannot be based on norms, but must be based on facts alone. In consequence, there is also no such thing as a Stufenbau for Ross. The other objection to customary international law as the source-norms of international law, however, cannot but prove fatal. As mentioned at various points in this book (especially in Section 3.2.5), customary law as a primitive form of norm-making cannot adequately conceive of an Ought in its formulation of a norm-content and cannot, therefore, formulate the norm- functions of empowerment and derogation, which are directed at other norms, not at human behaviour.
(2) One could imagine a kind of constitutional law of a different and unique form; a form different from all of international law’s sources – something that we might call ‘international consitutional law’ (Vửlkerverfassungsrecht). Positive inter- national law, however, does not support such a co-ordinating meta-meta-level above the sources of international law (Section 6.3).
39 ‘. . . wenn die Verfassung der Rechtsgemeinschaft nicht im Wege der Satzung, sondern im Wege der Gewohnheit zustande gekommen ist . . . Diese Situation kann man nicht dahin deuten, daò Gewohnheit von der durch Gewohnheit erzeugten, also positivrechtlichen, Verfassung als rechtserzeugender Tatbestand eingesetzt wird. Das wọre eine petitio principii. Denn wenn die posi- tivrechtliche Verfassung . . . im Wege der Gewohnheit erzeugt werden kann, muò schon vorausge- setzt werden, daò Gewohnheit ein rechtserzeugender Tatbestand ist.’ Kelsen (1960) supra note 7 at 232 (Ch 35 b) (emphasis added).
40 The existence of the petitio principii was pointed out by Danilenko as reason for Kelsen’s purported rejection of the thesis.
41 Ross (1947) supra note 26 at 83 (emphasis added).
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(3) In a 1969 paper Alfred Verdross proposed a multiplicity of custom-creative processes:
Because it is probable that each of the different theories [on customary law] contain some correct elements, the presumption of one mode of creation for all norms of customary international law is probably not correct. . . . It is impossible to found all unwritten norms of international law on the same basis of validity.42
He was guided by the deficiencies he identified in common theories about custom-formation and he proposed to accept all procedures that usually succeed in creating customary international law. The adoption of this theory would mean that the unity of customary international law as a source of international law no longer exists and that ‘unwritten international law’ would take its place as a mere empirical collection, not as a normative system,43 whereas there would be a multitude of sources, one each for every method of creating ‘customary’ law.’ The theory proposed by Verdross also means begging the question and transcending the Is–Ought dichotomy. How can we find out what ‘process’ usually creates customary international law if we do not know when law has validly been created?
Knowing when law is usually created requires knowing the meta-norm of cus- tomary international law-creation – and finding this is the object of the exercise.
Dispensing with the need for a norm to create another norm would at best mean abandoning the idea of normative orders; at worst it would mean the inability to cognise norms as norms.
(4) The view is not uncommon that constitutional norms originate outside any sources, for example as direct product of a formless consensus of states44 (cf.
42 ‘Da es aber wahrscheinlich ist, daò in jeder der verschiedenen Theorien ein richtiger Kern steckt, liegt die Vermutung nahe, daò die Annahme einer einheitlichen Entstehungsart aller Normen des VGR der Kritik nicht standhalten kann. . . . Es ist unmửglich, alle ungeschriebenen Normen des VR auf denselben Geltungsgrund zurückzuführen.’ Alfred Verdross, Entstehungs- weisen und Geltungsgrund des universellen vửlkerrechtlichen Gewohnheitsrechts, 29 Zeitschrift fỹr auslọndisches ửffentliches Recht und Vửlkerrecht (1969) 635–653 at 636 and 649, respectively.
This problematic approach is widespread: Albert Bleckmann, Die Aufgaben einer Methodenlehre des Vửlkerrechts. Probleme der Rechtsquellenlehre im Vửlkerrecht (1978) 19–20; Robert Kolb, Selected problems in the theory of customary international law, 50 Netherlands International Law Review (2003) 119–150 at 128–130. Helmut Strebel talks about the ‘the dilemma created, [on the one hand] by the dogma of the generality of the term “customary law” and, on the other hand, [by] the unmistakeable diversity of the conditions for the creation of customary law’ ‘durch das Dogma von der Allgemeingültigkeit des Gewohnheitsrechtsbegriffs und, andererseits, die unver- kennbare Unterschiedlichkeit der Entstehungsbedingungen und Erfordernisse von Gewohnheits- recht geschaffenen Dilemma’ Strebel (1976) supra note 25 at 322.
43 Verdross had earlier sought to base both treaty and customary international law on a Grundnorm with the content pacta sunt servanda (which differed from Kelsen’s conception of that term). Verdross (1926) supra note 14.
44 Alfred Verdross, Die Quellen des universellen Vửlkerrechts (1973) 20 (This is one possible inter- pretation of that theory; another is introduced in Section 6.3.1); Hermann Mosler, The inter- national society as a legal community (1980) 16; cited in: Danilenko (1988) supra note 38 at 17.
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Section 6.1.1); Danilenko espouses a similar position.45 The argument that law is not just ultimately based on facts or on external ideals but that even its sources are directly based on these factors and that law has no role in determining what procedure creates law46 is surprisingly widely held. We will not repeat the objections against transcending the fundamental dichotomy of Is and Ought at this point.
The debate on the nature of this kind of norms (or ‘processes’) merely hides the uncertainty about the constitution of international law. Too much depends on what solution one has for that problem to be able to pronounce a winner here;
therefore, we shall leave the realm of terms and forms and enter the murky waters of bases and justification.