Canons of Construction

Presumptive rules used by courts when interpreting statutes — divided into linguistic canons (grammatical and structural) and substantive/normative canons (policy-based presumptions).

Elements / Test

Linguistic (textual) canons:

CanonRule
Expressio uniusExpression of specific things implies exclusion of others not mentioned
Ejusdem generisGeneral term following specific list limited to things similar to list
Noscitur a sociisAmbiguous word interpreted by its surrounding company
SurplusageEvery word has meaning; avoid interpretations making words redundant
Whole-act ruleSame term carries same meaning throughout the statute
Heading canonSection headings may be used as interpretive aids (though not controlling)
Last antecedentQualifying phrase ordinarily modifies only immediately preceding item

Substantive/normative canons:

CanonRule
Rule of lenityAmbiguous criminal statutes resolved in defendant’s favor
Presumption against retroactivityStatutes not applied retroactively without clear congressional statement (Landgraf)
Presumption against extraterritorialityU.S. statutes not applied abroad without clear statement (Morrison)
Federalism clear statement ruleCongress must speak clearly to intrude on state sovereignty (Gregory v. Ashcroft)
Constitutional avoidancePrefer interpretation that avoids serious constitutional questions
Remedial constructionRemedial statutes construed broadly to achieve their purposes
Sovereign immunityWaiver of sovereign immunity must be express and unambiguous
Indian canonAmbiguities in statutes relating to Indians resolved in Indians’ favor

Exceptions and Edge Cases

  • Competing canons: Canons often point in different directions; courts have discretion in choosing which to apply (Llewellyn’s “thrust and parry” critique)
  • Not binding: Canons are presumptions, not rules; they can be rebutted by strong evidence of contrary meaning
  • New textualism: Uses only linguistic canons; rejects substantive canons as substantive policy choices that belong to Congress
  • Purposivism: Uses canons as tools to serve statutory purpose, not as rigid constraints

Policy Rationale

Canons provide predictability and consistency; they reflect embedded background principles against which Congress is assumed to legislate. Critics argue they are manipulable and that conflicting canons give judges license to choose outcomes.

Key Cases

CaseRule
Gustafson v. Alloyd Co. (1995)Noscitur a sociis — “prospectus” in § 12 read in context of surrounding statutory scheme
Yates v. United States (2015)Ejusdem generis and whole-act rule applied to limit “tangible object” in Sarbanes-Oxley
Landgraf v. USI Film Products (1994)Presumption against retroactivity: statute does not apply to pending cases unless Congress clearly states otherwise

Covered In