Outline sources of international treaties
- Customary International Law: It is convenient to start with customary law as this is both the oldest source and the one which generates rules binding on all States. Customary law is not a written source. A rule of customary law, for example requiring States to grant immunity to a visiting Head of State.
- International conventions: International treaties are contracts signed between states. They are legally binding and impose mutual obligations on the states that are party to any particular treaty (states parties). The main particularity of human rights treaties is that they impose obligations on states about the manner in which they treat all individuals within their jurisdiction.
- Writings: The writings of international lawyers may also be a persuasive guide to the content of international law but they are not themselves creative of law and there is a danger in taking an isolated passage from a book or article and assuming without more that it accurately reflects the content of international law.
- General principles of law: In the application of both national and international law, general or guiding principles are used. In international law they have been defined as ‘logical propositions resulting from judicial reasoning on the basis of existing pieces of international law’. At the international level, general principles of law occupy an important place in case-law regarding human rights.