The duty of courts is to give effect to the meaning of statutory words as intended by Parliament. In common with how all speech acts are understood, the meaning is that which a reasonable person would understand to have been intended by the words used in their context. One presumption, or inference based on common experience of legislative acts, is that when Parliament uses words with a common or ordinary meaning then the words are intended to bear that ordinary meaning. That presumption also reflects the expressed goal of parliamentary drafting for clarity and familiarity in order to ensure the transparency and intelligibility of statute law. That presumption can be further reinforced by another presumption, that words repeated in a statute are used with the same meaning.
Nevertheless, even when Parliament does not provide a specific definition of particular statutory words there are instances where Parliament will be understood not to have intended that those undefined statutory words should bear their ordinary meaning. For instance, the more that the ordinary meaning of the words would impair common law rights, and the more fundamental are those rights, the less likely it is that the words will be understood to have been intended to bear their ordinary meaning and the more unusual the meaning of the words that can be countenanced as having been intended. More unusual meanings of words can also be countenanced in a range of more common circumstances, and will be likely to be so countenanced where several of these circumstances exist in combination: where the ordinary meaning of the words is contrary to the scheme of the legislation; where the ordinary meaning of the words runs contrary to the legislative history; and where the ordinary meaning of the words is inconsistent with the expressed understanding of the legislative operation in extrinsic materials. None of these matters of context has any greater a priori weight than any other.
Consistently with this approach, courts have sometimes interpreted statutory words in a manner contrary to their ordinary meaning in order to give effect to parliamentary intention. For instance, the Privy Council, dismissing an appeal from this Court, held that the word "arrangement" in the former s 260 of the Income Tax and Social Services Contribution Assessment Act 1936 (Cth) does not bear the ordinary meaning of an initial plan but includes "all the transactions by which [the plan] is carried into effect". This Court held that the word "interview" in former s 570D of the Criminal Code (WA) does not bear the ordinary meaning of a formal or structured meeting but means "any conversation between a member of the Police Force and a suspect", including an informal conversation initiated by the suspect. And this Court held that the words "otherwise mutilates" in s 45(1)(a) of the Crimes Act 1900 (NSW) do not bear the ordinary meaning of injury or damage that is more than superficial112 but instead have an open-textured meaning of engaging, otherwise, in the undefined practice of female genital mutilation.
The ultimate question in every case is the meaning of the words, in all their context, as they were intended by Parliament. Of course, the prolific references by courts to parliamentary intention are not to a subjective intention of any or all of the members of Parliament. Rather, they are shorthand to describe the same general approach that people take to the understanding of language. Words of a statute are not a secret code for lawyers. They are enacted to be read and understood by reasonable, informed people using their everyday tools of language. This involves considering what was intended by the speaker, here the construct of Parliament. Consideration of a speaker's intention requires the speaker's purpose and the context of the spoken words to be considered at the same time as their "ordinary meaning". So too with the interpretation of words enacted by a Parliament. Ordinary meaning, and usage of words in the legislation with consistent meaning, are therefore only two indicia, albeit usually very powerful indicia, of the intention of the Parliament