What are the Sources according to the Art. 38?

Let me now turn away from modern social science theory to international law itself, with its concepts, terminology, and traditions dating far back into the history. Almost every text on international law starts with the elaboration on the sources of law (for example Barker 2000, Wallace 2002, Harris 2004). O’Connell (1971; in Barker 2000) argues the term “source” is misleading for it associates with the way in which international rules come about. Jennings (1995), in response, identifies four distinct meanings of the term. First, there is the source in the historical meaning. Second, sources of law are the criteria for identifying (binding) rules of law, and thus distinguishing them from other rules (such as that of morality or etiquette). This will be the meaning most often referred to in this paper. The third usage is related to the second, and denotes the sources as the material evidences of law – law reports, collection of treaties and the like (following Jennings 1995: 1165). Lastly, sources of law can also refer to the methods or procedures by which the law is actually made or amended. Thus, the sources of law mean most importantly the constituting parts of international law – that is, where one finds international law and what gives the rules their legal status. Or, in other words, the sources define the mental process of how do we recognize law when we see it, which is referred to as operationalization of the term ‘international law’ (sources of law as sources of obligation, as Fitzmaurice 2000 rightly refers to them). Since there is no world government which would enact legislation in a top-down manner, this part of international law theory is of particular importance. The general legal consensus over the sources of international law is the following. Stipulated in the Article 38 of the Statute of the International Court of Justice (ICJ), the court shall base its decisions on:

1. Treaties

2. International customary law

3. General principles of law (Schwarzenberger 1957; in Harris 2004: 18; see also Appendix). In addition, the court may also apply judicial decisions or authoritative writings as “subsidiary means for the determination of the rules of law” (see Appendix for the whole Art. 38). This clearly sets the recognized sources of law apart from the other forms of legalization, such as the natural law concept, general moral postulates, or what is called the doctrines of international law (the views of writers; Harris 2004: 18). This distinction presupposes that law at a time is distinct from any moral or normative postulates of any human mind, which is understandable from the point of view of clarity for the lawyers deciding a case. Let me now dwell on each of the sources in a greater depth individually.

1 Treaties

By singing a treaty, it is understood that the states express their consent (or ‘good will’) to be bound by the rules stipulated in it. This way, treaties can be seen as binding and as such a source of law by definition. The enforcement of such proclamation of good will is, however, questionable in an anarchic field of international relations. In order to be possible to enforce in the international politics, the “treaty game” is said to require iteration (in one-shot game the dominant strategy is to defect, as in the Prisoner’s Dilemma; Setear 1996 in Barker 2000: 65). In this light, Adolf Hitler’s infamous canon of not sticking to the agreements when it is not anymore favorable, in theory, is an inferior game strategy in the long run, for all other players would equally defect on cooperation with the German Reich (one could even argue it proved to be inferior in this way). Inter-state treaties are formally at the top in the hierarchy of the sources of law, which is exemplified also by its primary position in the Art. 38 of the ICJ Statute (Lauterpacht 1970)1. This sets it clearly apart from national legislation, where the freedom to enter into contracts is rather strictly regulated (by, for example, minimum wage laws, product quality standards, illegalization of drugs, etc.). As mentioned above, there is a principle of good faith in treaties as sources of law (Latin: pacta sunt servanda – pacts are to be obeyed). The exception being jus cogens - principles of international law so fundamental that no nation may ignore them or attempt to contract out of them through treaties. States are not allowed to enter legally into an agreement institutionalizing slave trade, for example (discussed more extensively below), to behave in a certain manner even if they subsequently change their mind by any coincidence. This is now also codified in the Vienna Convention on Law of Treaties Art. 26, which cites: “every treaty in force is binding upon the parties to it and must be performed by them in good faith” (Barker 2000: xiv). In order to provide for a leeway in case the states wish so, treaties can however also involve opt-out stipulations as known from civic law. Now, the question of universal legality comes into play. Many lawyers would argue that treaties cannot form a basis of proper (universal) law, because they are hardly ever universal - they are most often bilateral, statistically rather rarely involve many states. How can then such a treaty (between two or more states) be regarded as general law binding other parties too? In fact, it can only if all states are parties to the treaty, which happens very rarely (one can possibly think of United Nations Security Council resolutions having the source in the United Nations Charter signed by all UN members). The answer to this question lies in the next source of international law and pertains to state practice: if states not-bound by the treaty nevertheless adhere to its stipulations, the treaty can be viewed as a customary international law.