20) What is the weight of this source of international law?

The second subsidiary source is said to be judicial decisions and the teachings of the most highly qualified publicists of the various nations. Debate as to the meaning of this has been lengthy and intense. It is stated in Article 38 as being only a subsidiary means for the determination of rules of law – that is, it is not the rules themselves. What does this mean? The first point you should understand here is that international law makes no use of the common law system of stare decisis. In international law no court binds itself or any other court by its decisions and it is explicitly stated in the Statute of the ICJ that decisions have no binding quality beyond the parties to a particular case. Nevertheless, as you will quickly appreciate if you read some ICJ cases, they do refer to earlier relevant cases in order to identify the law. Although the analogy is not exact, in international law judicial decisions and the writings of the highly qualified publicists are used as, in the common law system, decisions from different jurisdictions and the writings of legal academics are used. That is, they may be more or less persuasive not because of their status but because of the logic in their reasoning and argument.

Finally there are some resources recognised as potential sources of international law which do not appear in Article 38. The most important of these are Resolutions of international organisations which may carry weight of their own in addition to evidencing state practice.

Judicial decisions

The decisions of international and municipal courts and the publications of academics can be referred to, not as a source of law as such, but as a means of recognizing the law established in other sources. In practice the International Court of Justice does not refer to domestic decisions although it does invoke its previous case-law.

There is no rule of stare decisis in international law. The decision of the Court has no binding force except between the parties and in respect of that particular case.[27] Nevertheless, often the Court would refer to its past decisions and advisory opinions to support its explanation of a present case.

Often the International Court of Justice will consider General Assembly resolutions as indicative of customary international law.

Juristic writings

Article 38(1)(d) of the International Court of Justice Statute states that the 'teachings of the most highly qualified publicists of the various nations' are also among the 'subsidiary means for the determination of the rules of law'. The scholarly works of prominent jurists are not sources of international law but are essential in developing the rules that are sourced in treaties, custom and the general principles of law. This is accepted practice in the interpretation of international law and was utilised by the United States Supreme Court in The Paquete Habana case (175 US (1900) 677 at 700-1).