^{page 374 note 1} This metaphorical expression has often been criticized; in our text, however, the term is sufficiently clear to indicate a general ground used by a competent organ in determining what is the applicable law.

^{page 374 note 2} The full text of the article, otherwise well known, is reproduced here for the sake of convenience:

1. The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply

a. international conventions, whether general or particular, establishing rules expressly recognized by the contesting States;

b. international custom, as evidence of a general practice accepted as law;

c. the general principles of law recognized by civilized nations;

d. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.

2. This provision shall not prejudice the power of the Court to decide a case ex aequo et bono, if the parties agree thereto.

^{page 375 note 1} It should be remembered, however, that attention has been paid to this aspect by two Danish authors in their doctoral dissertations. A Ross has dealt with it as a problem of the general theory of law in his Theorie der Rechtsquellen (1929), reaching the remarkable conclusion: “Das System ist die letzte Rechtsquelle” (p. 309)Google Scholar. M. Sørensen in Les Sources du droit international (1946) has drawn attention to some principles of international law resulting from the very structure of international law (p. 116 f.).

^{page 375 note 2} Principles of International Law, 1952, p. 418Google Scholar. Cf. also Théorie du droit international coutumier, in Revue internationale de la théorie du droit, 1939, p. 273 f. Kelsen states that the rule pacta sunt servanda is not the basic norm of international law but is a rule of customary international law, the latter representing a higher level in the hierarchical structure of the international legal order than conventional international law.

However, it does not become quite clear what the substance of Kelsen's norm “the states ought to behave as they have customarily behaved” really is. “Custom” is not, like “treaty” a notion with sharply definable limits. Different theories may be possible as to the general conditions under which the existence of a binding, law-creating agreement is to be assumed, but on the basis of any of those theories it can be exactly established whether or not such agreement is present. It is impossible, however, to indicate tests for determining the moment when usage becomes binding, law-creating, and, in this sense, becomes custom.

^{page 375 note 3} Op. cit., p. 281: “Die Grundnorm lässt sich nur verstehen als Grundnorm, wenn sie als Abstraktion von wirklichen Zwangshandlungen betrachtet werden kann; und diese lassen sich umgekehrt nur als rechtliche verstehen, wenn sie als Konkretisation (durch eine Reihe von Stufen) von einer vorausgesetzten Grundnorm betrachtet werden können. Die Wirklichkeit des Rechtes liegt in der durchgehenden Korrelation.”

^{page 376 note 1} Status of Eastern Carelia, P.C.I.J., Series B, No. 5, p. 27.

^{page 376 note 2} Question concerning the Acquisition of Polish nationality, P.C.I. J., Series B, No. 7, p. 16.

^{page 376 note 3} Case of the S.S. “Lotus”, P.C.I. J., Series A, No. 10, p. 18.

^{page 376 note 4} Le Fur, L., Recueil des cours de l'Académie de droit international, 1927, III, p. 413.Google Scholar

^{page 377 note 1} Le Fur, loc. cit.

^{page 378 note 1} Effect of Awards of Compensation made by the United Nations Administrative Tribunal, I.C.J. Reports, 1954, p. 54 f. The italics are by the present author.

^{page 378 note 2} In this connection the relevant parts of the written and oral statements should be taken into consideration, particularly Distr. 54/17, pp. 73, 78, 85, 100, 194 f. Distr. 54/95, pp. 59 f., 91 f.

^{page 379 note 1} Communiqué of the Czechoslovak Government of 30 September, 1938 and Broadcast of the Czechoslovak President.

^{page 379 note 2} Judgment of the Nürnberg International Military Tribunal, American Journal of International Law, 1947, p. 196.Google Scholar

^{page 379 note 3} H. Lauterpacht, Report on the Law of Treaties, International Law Commission, U.N. Doc. A/ CN. 4/63, 24 March 1953, p. 198, refers to such inconsistency as a ground of invalidity. Previously undertaken obligations were contained in Hague Conventions I of 1898 and 1907, in the General Treaty for the Renuncation of War of 1928, and in the Arbitration Convention between Germany and Czechoslovakia of 1925, signed at Locarno.

^{page 379 note 4} Referring to French-British propositions of 19 September 1938, De Martens, , N.R.G. 3e s., XXXVI, p. 24 f.Google Scholar

^{page 380 note 1} French-Czechoslovakian, Statement of 22 08, 1944.Google Scholar

^{page 380 note 2} Lauterpacht, , op. cit., p. 177.Google Scholar

^{page 380 note 3} De Martens, , op. cit., p. 341.Google Scholar

^{page 380 note 4} U.N. Doc. E/CN. 6/79, 21 January 1949, p. 51.

^{page 381 note 1} It may be left out of consideration here in how far the German-Czechoslovak mixed commission was intended to function as a judicial body: “Zur Prüfung und Behandlung aller Fragen, die sich bei der Durchführung dieses Vertrages ergeben, wird ein gemischter Ausschuss gebildet, in den jede der beiden Regierungen eine gleiche Zahl von Vertretern entsendet.”

^{page 382 note 1} Conf. Oberlandesgericht Vienna 7 03 1946, 9 January 1947, 5 March 1947, 9 April 1947Google Scholar (Juristen-Zeitung, Österreichische, 1948, p. 518 n.)Google Scholar

^{page 383 note 1} Cf. Verzijl, J. H. W., Mededelingen der Koninklijke Nederlandse Academie van Wetenschappen, Afd. Letterkunde, Deel 1, No. 2, 1938, p. 13 f.Google Scholar

^{page 383 note 2} Ross, , op. cit., p. 334 f.Google Scholar

^{page 383 note 3} Fitzmaurice, G. G. in British Year Book of International Law, 1951, p. 1 f.Google Scholar

^{page 384 note 1} Kelsen, H., Principles of International Law, 1952, p. 308.Google Scholar

^{page 384 note 2} Ibid.