Hayne J
Bell J
55.
the principles associated with s 51(xxxi) give particular effect to wider considerations. Hence, as Dixon CJ said in Attorney-General (Cth) v Schmidt[1]:
"The decisions of this Court show that if par (xxxi) had been absent from the Constitution many of the paragraphs of s 51, either alone or with the aid of par (xxxix), would have been interpreted as extending to legislation for the acquisition of land or other property for use in carrying out or giving effect to legislation enacted under such powers. The same decisions, however, show that in the presence in s 51 of par (xxxi) those paragraphs should not be so interpreted but should be read as depending for the acquisition of property for such a purpose upon the legislative power conferred by par (xxxi) subject, as it is, to the condition that the acquisition must be on just terms. … [W]hen you have, as you do in par (xxxi), an express power, subject to a safeguard, restriction or qualification, to legislate on a particular subject or to a particular effect, it is in accordance with the soundest principles of interpretation to treat that as inconsistent with any construction of other powers conferred in the context which would mean that they included the same subject or produced the same effect and so authorized the same kind of legislation but without the safeguard, restriction or qualification." (emphasis added)
Of course, the caveat entered[2] by Dixon CJ is important: "it is necessary to take care against an application of this doctrine to the various powers contained in s 51 in a too sweeping and undiscriminating way". But the present cases do not depend upon any refinement to the general proposition that was identified in Schmidt. Rather, they turn upon the observation that the relevant constitutional inquiry is whether the impugned law is a law with respect to the acquisition of property from any person.
To adopt the metaphor of abstraction[3] often used in connection with s 51(xxxi), it is a legislative power with respect to the acquisition of property which is abstracted from other heads of legislative power. Section 51(xxxi) does not abstract any more widely or differently expressed power. In particular, to persist with the metaphor, there is no abstraction of legislative power the exercise of which can be said to have some deleterious effect on the worth of a business, or to "take" or "extinguish" the property of some person, unless there is an
