Is a motorcycle a motor vehicle? Judges settle such puzzles daily
Suppose a law says every motor vehicle on public roads must be registered, but never defines the term. A rider fined for an unregistered motorcycle argues it does not qualify. Now a court must decide what lawmakers meant, and the plain-language rule suggests ordinary road vehicles, not aeroplanes or bicycles.
Legislation is never perfectly clear, for several reasons. Words drift: let once meant to hinder and now means to permit, and peculiar can mean either belonging specifically to something or simply odd. New technology throws up situations drafters never imagined, such as whether an embryo created by a novel cloning method counts under a law written when fertilisation was the only route. Political compromise during passage can also leave deliberate fuzziness.
The discipline grew up in England, where Parliament never produced a full legal code and courts built the common law case by case. Once a judge's reading of a statute became binding on later courts, a consistent method was needed. English judges aimed to carry out the intention of Parliament and developed three main approaches: the literal rule, the golden rule and the mischief rule. The scholar Francis Bennion doubted that any such simple devices really explain how interpretation works.
Courts also start from built-in presumptions. Criminal offences are assumed to require a guilty mind, a principle confirmed in Sweet v Parsley. A statute is presumed not to bind the Crown, not to operate retrospectively, not to strip anyone of liberty or property, and not to alter the common law unless it says so. General words are read in light of the specific ones around them. In Britain, Parliament alone makes law, yet courts keep sole authority to say what it means.
American and Australian courts begin with the text read in its ordinary sense. The US Supreme Court said in 1992 that a legislature must be presumed to say what it means and mean what it says, and when the words are unambiguous the inquiry ends there. A Virginia ruling from 1929 adds that no part of an act should be treated as meaningless if avoidable, known as the rule against surplusage.
Source: Statutory interpretation
