jus cogensn.

1895 W. H. Rattigan Private Internat. Law vi. 163 A jus cogens regulating rights of this description is a product of modern commercial and intellectual activity, and finds no place, for instance, in the jurisprudence of the Roman Empire.

1937 Amer. Jrnl. Internat. Law 31 571 The answer to this question depends on the preliminary question, whether general international law contains rules which have the character of jus cogens.

1945 M. Wolff Private Internat. Law iii. 168 Savigny..clearly showed that the rules of an absolute, imperative character (the ius cogens) to be found in any legal system are of two kinds. There are first of all those rules ‘that are enacted merely for the sake of persons who are the possessors of rights’, such as the laws limiting the capacity to act on account of age or sex, or laws concerning the transfer of property; and secondly the rules that are not made solely for the benefit of single individuals but rest on moral grounds, or on the ‘public interest’… ius cogens privatorum pactis mutari non potest.

1957 G. Schwarzenberger Internat. Law (ed. 3) I. xx. 352 In this respect, the rules governing the principle of the freedom of the seas are not jus cogens which as such is unalterable, but as much jus dispositivum as any of the other rules of international law.

1960 F. A. Mann in Brit. Year Bk. Internat. Law 1959 45 Lord McNair must allow the jus cogens of the proper law to override the general principles which are merely incorporated into it.

1965 Texas Law Rev. XLIII. 455 The problem of international jus cogens can be stated in a simple question: Are there rules of international law which, by consent, individual subjects of international law may not modify?

1969 Vienna Convention on Law of Treaties 18 in Parl. Papers 1968–9 (Cmnd. 4140) LV. 395 Treaties conflicting with a peremptory norm of general international law (jus cogens). A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. For the purposes of the present Convention, a peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.

1971 M. B. Akehurst Mod. Introd. Internat. Law (ed. 2) iii. 60 The technical name now given to the basic principles of international law, which states are not allowed to contract out of, is ‘peremptory norms of general international law’, otherwise known as jus cogens.