Rules and Canons of Construction
Domain 2 - Rules and Canons of Construction
This domain tests your ability to name and apply the canons accurately, and to avoid using them as mechanical substitutes for context. The exam favours a short identification plus a reasoned application to the words before you.
Lexical canons
- Ejusdem generis: general words following a list take their colour from the class. “Cars, motorcycles and other vehicles” may include vans, not aircraft. The list must form a coherent class.
- Noscitur a sociis: a word is known by the company it keeps. “Industrial” in “industrial and commercial premises” may exclude a dwelling.
- Expressio unius: express mention of one thing may exclude another, but only where the statutory context supports exclusivity.
- Reddendo singula singulis: distribute words to their proper referents, especially in deeds and contracts with paired obligations.
- Ut res magis valeat quam pereat: prefer an interpretation that gives the instrument effect over one that defeats it.
- Contra proferentem: ambiguity in a clause drafted by one party may be construed against that party, but not where the clause is negotiated or the meaning is clear.
Structural and conflict canons
Generalia specialibus non derogant: a specific provision prevails over a general one on the same subject. Later statutes may impliedly repeal earlier ones only where the inconsistency is irreconcilable. Penal and taxing statutes are construed strictly, but not artificially: clear words still apply. Presumptions (against retrospectivity, against interference with vested rights) yield to express language.
Worked example
A lease grants “the right to park private cars, motorcycles and other vehicles in the forecourt”. The tenant parks a light delivery van. Applying ejusdem generis, “other vehicles” takes colour from private cars and motorcycles: the class is small private conveyances, not commercial delivery vans. The purpose clause and the forecourt’s size may reinforce that reading. If the lease instead said “cars, motorcycles and other mechanically propelled vehicles”, the wider express words would include the van, and ejusdem generis would not narrow them.
Traps
Do not apply a Latin canon without explaining the textual trigger. Do not use contra proferentem where both parties negotiated the clause. Do not treat expressio unius as conclusive in every statute. Do not confuse generalia specialibus with the rule that later legislation prevails. Do not let strict construction of a penal statute produce a result that the words do not permit.