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Sources of law

See also the discussion of sources of law in our Research Study on Text-driven Law.

Working definition

  1. The sources of law refer to the set of written and unwritten resources from which  binding legal norms are ’drawn’; the sources do not contain information about the law,  they constitute the law as they decide what counts as law 
  2. The sources of law are usually limitatively summed up as: 

    • written sources: 

      1. international treaties  
      2. legislation 
      3. case law
      4. doctrine 
    • unwritten sources: 

      1. fundamental principles, and 
      2. customary law 
  3. Treaties, legislation, case law, fundamental principles and custom present binding legal norms  
  4. A constitution can be written (legislation) or unwritten (customary law); it constitutes the legal powers of the state and the rights of its citizens 
  5. Doctrine contributes to the interpretation of binding legal norms, though it is not binding in itself, the same goes for recitals in treaties, opinions of advocats general (advisors) of highest courts and other formal advisory bodies (e.g. the European Data Protection Board)  
  6. The binding force of fundamental legal principles do not depend on whether or not and how they have been codified in written sources; they are tied up with the core tenets of the rule of law and the moral and institutional grounding of the law. 
  7. Customary law binds due to usus (actual adherence) and opinio necessitatis (a shared sense of obligation) 
  8. To select and apply a relevant legal norm implies an act of interpretation; the act of selection and application cannot be reduced to a logical sequence though it must be justifiable in the form of a syllogism; the need to justify the choice and the interpretation of a legal norm restricts the decisional space of public administration and the courts, thus bringing them under the rule of law 
  9. Interpretation cannot be arbitrary, legal doctrine distinguishes grammatical, systematic, historical and teleological interpretation, i.e. taking into account the ordinary meaning of the relevant terms, the place of the norm within the relevant legal source, the legislature’s intent as derived from official documents, and the aims of the relevant legal source; courts have discretion in selecting and combining these methods of interpretation but the exercise of such discretion is bounded by the demands of legal certainty, justice and purposiveness of the law.

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This page was last updated on 16 March 2023.