A source of law is a method by which the rules have been discovered or created. According to some of the eminent Jurist of International law following are the sources of International Law

1) Lawrence :

             According to Lawrence, if we take the source of law means its beginning as law having with all the authority required to give it binding force, then in respect of International Law there is one source of law and that is consent of Nations. This consent may be either tacit (custom) or express (treaties).

2) Oppenheim : 

               Oppenheim also shares the opinion of Lawrence According to Oppenheim Treaties and Customs are regarded as the exclusive sources of International Law.
Therefore the Sources of International law are two-fold, namely -

                          1 Express consent which is given when States conclude a treaty stipulating certain rules for the future International conduct of the parties.

                          2 tacit consent, that is implied consent or consent by conduct.

3) Brierly :

                  According to Professor Brierly the main Sources of International law are custom and reason.

4) Westlake

             Westlake also says that custom and reason are two sources of International law.

5) J. G. Starke:

             The material sources of International law may be defined as "the actual materials from movies and international lawyers determine the rules applicable to a given situation ". These materials fall into 5 principal categories.
               1. Custom
               2. Treaties
               3. The decision of Judicial or Arbitral Tribunal.
               4. Juristic Work
               5. Decisions on the determination of the organs of International Institutions.

According to Article 38(1) of the Statute of the International Court of Justice (established by the Charter of the United Nations) defines the Sources of International law as under:

 (a) International conventions, whether general or particular, establishing rules expressly recognised by the contesting states;

 (b) International custom, as evidence of a general practice accepted as law;

 (c) The general principles of law recognised by civilised 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.

Article 38 (2) Provides that the Article 38 (1) shall not prejudice the power of the Court to decide a case ex aequo et bono (means in justice  and good faith), if the parties agree thereto.


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