Law Legal ReasoningCanons of Construction: Reading What a Statute Says
Sage the owl perches at a tall reading desk, magnifying glass resting on an open statute book, sticky notes marking key words under warm lamplight in a quiet library.
- Define the plain-meaning rule and state when a court applies it.
- Explain what a canon of construction is and why courts use canons to resolve ambiguity.
- Apply ejusdem generis to limit a general phrase to items similar to a specific list.
- Apply expressio unius est exclusio alterius to identify what a statute deliberately left out.
- Distinguish canons of construction from free judicial invention.
Key terms
- Plain-meaning rule
- The principle that a court applies a statute as written when its ordinary words are clear and unambiguous.
- Canon of construction
- A shared judge-made rule of thumb for interpreting ambiguous statutory text.
- Ejusdem generis
- Latin for 'of the same kind'; a general phrase after a list covers only items similar to those listed.
- Expressio unius
- Short for 'to express one thing is to exclude others'; naming specific items signals unnamed ones are excluded.
- Ambiguity
- A condition where statutory words can reasonably bear more than one meaning, prompting interpretive tools.
Starting With the Plain Text
Interpretation is anchored in the words the legislature actually enacted, because judges cannot consult lawmakers after the fact. Under the plain-meaning rule, when the ordinary sense of the text is clear, the court applies it exactly as written without reaching for legislative history or its own sense of fairness. Only when the words are genuinely ambiguous — when a reasonable reader could take them more than one way — do courts move on to canons of construction. Identifying whether ambiguity truly exists is therefore the first analytical step.
Two Workhorse Canons
Ejusdem generis and expressio unius operate in opposite directions but share a goal: respecting the legislature's word choice. Ejusdem generis narrows a catch-all phrase to the kind of items in the preceding list, so 'cars, trucks, and other vehicles' means similar motorized road vehicles, not a stroller. Expressio unius reads a deliberate omission as exclusion, so a list of named items implies that unlisted items were intentionally left out. Both canons constrain interpretation to the text rather than freeing a judge to invent a preferred result.
Worked examples
Read 'cars, trucks, and other vehicles' with ejusdem generis.
- Issue: Does the catch-all 'other vehicles' include a bicycle?
- Rule: Ejusdem generis limits a general phrase to items of the same kind as the specific list preceding it.
- Application: The listed items — cars and trucks — are motorized road vehicles, so 'other vehicles' covers similar machines like vans and buses, not a human-powered bicycle.
- Conclusion: A bicycle falls outside 'other vehicles' under ejusdem generis.
Answer: A bicycle is not covered; 'other vehicles' means similar motorized road vehicles.
Apply expressio unius to an unlisted additive.
- Facts: A food-safety law names four specific additives as banned.
- Rule: Expressio unius treats the naming of specific items as signaling that unnamed items are deliberately excluded.
- Application: A fifth additive does not appear on the enumerated list, so its omission implies intentional exclusion rather than oversight.
Answer: The fifth additive is not covered — its omission is read as deliberate exclusion.
Activity
Sort each court move under the canon it best illustrates.
Practice
Use ejusdem generis to decide whether a skateboard falls under a statute banning 'cars, trucks, and other vehicles.'
Use expressio unius to determine whether a tax exemption listing apples, oranges, and pears covers mangoes.
Common mistakes to avoid
- Ambiguity lets a judge pick any fair ruleCanons of construction and the statute's own text constrain interpretation, so a judge cannot freely substitute a personally preferred result for the words enacted.
- A catch-all phrase covers literally anythingEjusdem generis limits a general phrase to items similar to the specific list, so it does not sweep in unrelated things like strollers or bicycles.
Check your understanding
Under the plain-meaning rule, when should a court apply a statute exactly as written?
A statute bans "cars, trucks, and other vehicles." Using ejusdem generis, how should "other vehicles" be read?
Which statement best describes the expressio unius canon?
A student says: "If a statute's words are unclear, the judge can just pick whatever rule feels fair." Why is this wrong?
Recap
Statutory interpretation begins with the plain-meaning rule and turns to canons only when text is ambiguous, using ejusdem generis to narrow catch-all phrases and expressio unius to treat omissions as deliberate exclusions, always anchored to the enacted words.
Reflect
Why is anchoring to the statute's words, rather than to fairness, important for predictable law?