In This Article Expand or collapse the "in this article" section Non liquet

  • Introduction
  • Reference Works
  • General Overviews
  • Categories of Non Liquet
  • Statutes and Rules of Procedure of International Courts and Tribunals

International Law Non liquet
Ulrich Fastenrath, Franziska Knur
  • LAST REVIEWED: 31 March 2016
  • LAST MODIFIED: 31 March 2016
  • DOI: 10.1093/obo/9780199796953-0130


The term non liquet originated in Roman law and means “it is not clear.” It refers to a situation in which a competent court or tribunal fails to decide the merits of an admissible case for whatever reason, be it the absence of suitable law, the vagueness or ambiguity of rules, inconsistencies in law, or the injustice of the legal consequences. The concept of non liquet does not refer to situations in which a court refuses to decide a case because it lacks jurisdiction or finds a claim inadmissible. The question of whether or not a judge is allowed to declare a non liquet is rooted deeply in both legal and political theory, and the different answers given reflect various natural law and positivist schools of thought. One of the first codifications of law, the Prussian Civil Code of 1794, required judges to seek guidance from a legislative committee if the wording of the Code was indistinct. It thus adopted Montesquieu’s view of the judge not as a noble-minded corrector of the legislator but as “bouche de la loi.” By contrast, the Swiss Civil Code confers legislative power upon judges, binding them to create law by recourse to jurisprudence and tradition as they deem appropriate should a case not be covered by a legal rule. Going even further, the French Code Napoleon forces judges to give a decision by penalizing denial of justice. In the United States, on the other hand, the political question doctrine allows courts to refrain from pronouncing a judgment under certain circumstances. Generally speaking, most domestic legal orders today prohibit courts from refusing to deliver a decision on the grounds of absence or obscurity of the law. In the realm of international law, the Advisory Committee of Jurists sought to avoid the possibility of a non liquet by including general principles of law among the sources of international law enumerated in Article 38 of the Statute of the Permanent Court of Justice (1920), thereby transforming the question of non liquet from a topic pertaining to judicial functions to one of legal theory: the completeness of law. Hereinafter, scholars have discussed the existence of a rule prohibiting non liquet. However, some commentators consider the International Court of Justice’s advisory opinion on nuclear weapons to be the first instance of a non liquet declared by an international court in the sense of a legal question not being answerable by recourse to existing international law. A somewhat different view is expressed in the Declaration of Judge Simma on the International Court of Justice’s Kosovo Advisory Opinion. He argues that the declaration of independence is a matter of fact outside the purview of international law.

Reference Works

The existence of non liquet situations in international law substantially depends on how law and the function of legal orders are conceived. Any in-depth analysis therefore must include a discussion of areas such as legal and political theory, linguistics, and economics, to reflect upon the limits of and interconnection among legislative and judicial activities, the concept of lawmaking, the role of judges in a world of sovereign states, and other factors. In so doing, the shortcomings and capacities as well as the aims of normative systems and the judiciary can be identified. Representative of such an approach are the comprehensive monographs by Siorat 1958 and Fastenrath 1991. In addition, the seminal controversy between Judge Hersch Lauterpacht and Professor Julius Stone on the prohibition or at least impossibility of a non liquet in international law is recorded here (Lauterpacht 1933 and Lauterpacht 1958; Stone 1954 and Stone 1959). Lauterpacht and Stone advanced a number of arguments: claims that there was a customary rule or a general principle prohibiting a non liquet; arguments that international law was complete given either the possibility of recourse to general principles (see Completeness of International Law through General Principles of Law) or a supposed residual rule of freedom (known as the Lotus principle: everything which is not forbidden is allowed—see Residual Rule of Freedom of Action); as well as claims concerning the law-creating activity of judges and their function (see Non Liquet and the Function of the International Judiciary). Furthermore, the contributions by Reisman 1969, Fitzmaurice 1974, and Weil 1998 are among the most cited in scholarly work on the role of non liquet in international legal practice.

  • Fastenrath, Ulrich. Lücken im Völkerrecht: Zu Rechtscharakter, Quellen, Systemzusammenhang, Methodenlehre und Funktionen des Völkerrecht. Berlin: Duncker & Humblot, 1991.

    Monograph discussing non liquet, across the different schools of international legal thinking, as the procedural consequence of gaps. Argues for non liquet in cases where judicial law creation has little chance of being accepted, where law is in the process of radical change, or where an existing rule is evidently not suitable to serve justice.

  • Fitzmaurice, Gerald. “The Problem of Non Liquet: Prolegomena to a Restatement.” In Mélanges offerts à Charles Rousseau: La communauté internationale. Edited by Charles Rosseau, 89–112. Paris: Pedone, 1974.

    Against the backdrop of a supposed “dogma” (p. 107) of avoiding non liquet this influential article on the notion and scope of non liquet in public international law raises the question of whether judicial legislation should be accepted as the price of avoiding a substantive non liquet.

  • Lauterpacht, Hersch. The Function of Law in the International Community. Oxford: Clarendon, 1933.

    Lauterpacht elaborates on his understanding of international law as a complete system. Regards the prohibition of non liquet as an a priori principle of public international law, derived from the function and practice of the international judge in the international legal system. Includes a review of arbitration case law. Reprinted in 2011 (Oxford: Oxford University Press).

  • Lauterpacht, Hersch. “Some Observations on the Prohibition of ‘Non Liquet’ and the Completeness of the Law.” In Symbolae Verzijl: Présentées au Prof J.H.W. Verzijl, à l’occasion de son LXXième anniversaire. Edited by F. M. van Asbeck, 196–221. The Hague: Nijhoff, 1958.

    The article is a response to Stone 1954. Lauterpacht contends that the prohibition of Non Liquet and the Completeness of International Law are well-established principles and even among “the most indisputably established rules of positive international law” (p. 200). Bases his findings on practice and a binding general principle. Stone 1959 is a reply to this article.

  • Reisman, William Michael. “International Non Liquet: Recrudescence and Transformation.” International Lawyer 3 (1969): 770–786.

    Contending that international courts frequently prescribe law in non liquet situations, Reisman discusses conditions and objectives of tribunals refraining from prescribing the law. Enumerates several limitations on the creative function of judges, including enforceability of decisions, political questions, and technical problems. Refers extensively to case law with a focus on international arbitration.

  • Siorat, Lucien. Le problème des lacunes en droit international: Contribution à l’étude des sources du droit et de la fonction judiciaire. Paris: Librairie générale de droit et de jurisprudence, 1958.

    Comprehensive monograph exploring gaps in public international law (treaties and custom) and the judiciary’s function in closing them. Distinguishes between five different types of gaps in international law reducing the appropriateness of a finding of non liquet to insuffisances sociales (i.e., issues deliberately left unregulated).

  • Stone, Julius. Legal Controls of International Conflicts. London: Stevens, 1954.

    Systematic study aimed at reconciling doctrine and practice of interstate relations. Reviews common arguments as to the possibility of a non liquet, provides historical context to the controversy, and assesses its implications for international peace and justice. Concludes that a tribunal’s refusal to decide a case might be preferable in some cases.

  • Stone, Julius. “Non Liquet and the Function of Law in the International Community.” British Yearbook of International Law 35 (1959): 124–161.

    Exhaustive reply to Lauterpacht 1958 reviewing in detail his arguments. Highlighting political, social, and economic aspects of the non liquet controversy Stone concludes that judges should be allowed to declare a non liquet if they deem this to be appropriate so as not to force them into overstretching their lawmaking function.

  • Weil, Prosper. “‘The Court Cannot Conclude Definitively . . . ’: Non Liquet Revisited.” Columbia Journal of Transnational Law 36.1–2 (1998): 109–119.

    Influential article founding the prohibition of non liquet in international adjudication on the will of the parties to have their dispute judicially settled. Resorting to the concept of polynormativity and self-interpretation as characteristics of the international system, accepts the possibility of non liquet in advisory opinions.

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