Statutory interpretation is a core judicial function: legislatures draft laws in general terms, and courts must decide how those words apply to concrete disputes. Because language is rarely self-executing, judges rely on established interpretive techniques, canons of construction, and—depending on the jurisdiction—legislative history, purpose, and constitutional values.
Common approaches include:
- Textualism — focuses on the ordinary meaning of the statutory words at the time of enactment. Associated in the United States with Justice Antonin Scalia, it treats unenacted legislative history with skepticism.
- Purposivism — looks to the broader purpose or "mischief" the legislature sought to address. The English Heydon's Case (1584) is an early articulation; modern purposivism is associated with scholars like Henry Hart and Albert Sacks.
- Intentionalism — seeks the subjective intent of the enacting legislature, often using committee reports, floor debates, and drafting history.
- Dynamic or evolutive interpretation — reads statutes in light of changed circumstances, a method also used by the European Court of Human Rights for treaties.
Courts also use linguistic canons such as ejusdem generis (general words follow the class of specific words), expressio unius est exclusio alterius (mention of one excludes others), and noscitur a sociis (a word is known by its companions). Substantive canons include the rule of lenity in criminal statutes and the presumption against extraterritoriality.
In the United States, the Chevron doctrine (from Chevron U.S.A. v. NRDC, 1984) long required courts to defer to reasonable agency interpretations of ambiguous statutes they administer; the Supreme Court overturned that framework in Loper Bright Enterprises v. Raimondo (2024). In the United Kingdom, Pepper v. Hart (1992) allowed limited use of Hansard. For MUN delegates and IR researchers, statutory interpretation matters because domestic implementation of treaty obligations frequently turns on how national courts read enabling legislation.
Example
In *Bostock v. Clayton County* (2020), the U.S. Supreme Court used textualist statutory interpretation to hold that Title VII of the Civil Rights Act of 1964 prohibits employment discrimination based on sexual orientation and gender identity.
Frequently asked questions
Statutory interpretation construes ordinary legislation and can be revised by the legislature passing a new law; constitutional interpretation construes a higher-order document that typically requires a formal amendment process to change.
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