Dual Characterisation Actors & Announcers Case (1982)
•    A single law can possess more than one character
•    If a law can be characterised as a law with respect to one of the Parliament’s enumerated powers, it is irrelevant that the law may also be characterised as with respect to a subject matter outside Cth power.
•    It is sufficient that one of the characters falls within a HOP
•    The task is not to single out the paramount character

Characterisation of Purposive Powers Leask v Commonwealth (1996)
•    a power defined by reference to purpose ie. Defence Power
•    If the head power is a purposive one, a law may be invalid if the legislation is not reasonably proportionate to achieving the purpose of that power.
•    ‘the court may have to inquire whether the law goes further than is necessary to achieve the purpose’ per Dawson J
•    Motives of parliament and purpose of law are relevant if legislative power granted is purposive Murphyores (1976)
•    Purpose of law refers to end or objective the legislation serves, not the underlying motive Kruger v Cth (1997)

Proportionality

•    Means of assessing the reasonableness of means chosen by the lawmaker to achieve certain ends.
•    An inquiry into the proportionality of a law involves value judgments of its reasonableness and appropriateness
•    Relevant in a number of areas
o    Determination of breaches of constitutional guarantees
o    The direct scope of purposive powers
o    A factor to be taken into account within the incidental power
•    Purposive criteria can only be invoked in cases where characterisation depends on purpose, eg for purposive powers (eg defence) and cases relying on the incidental power Cunliffe v Commonwealth (1994)

Severance & Reading Down

•    Applicable when statute:
o    cannot be characterised under a head of power
o    contravenes some express or implied limitation
•    When something can be severed or read down, it should be – s 15a  Acts Interpretation Act (1901) (not an imperative rule of law, only request)
Reading down
•    Where act is so general as to apply to matters beyond the Commonwealth’s power, the court can read it down so that it falls within a head of power
•    If the court is faced with more than one way to read down a statute to make it valid, it will decline to read down
•    In some cases the terms of the statute will indicate that it was not intended that any offensive provisions be read down.
•    Reading down must result in a ‘consistent and effective body of provisions’ Strickland v Rola Concrete Pipes per Barwick CJ

Hindmarsh Island Case (1997)
•    Act conferred powers upon a ‘person’ incompatible with the functions of a judge
•    The word ‘person’ was read down to mean ‘person that is not a judge’

Railway Servants Case (1906)
•    If legislative intention against reading down, then it can’t be done
•    Explicit reference to state railways meant act couldn’t be read down to include them
Severance
•    If court is unable to read down, it should try to sever the offending provision, and read the statue as if it was not there
•    If severing would have the effect of creating a new law, the court will not sever the provision (as to sever would be to undertake a legislative role)
•    Can’t sever if to do so would make a substantial difference or a new law altogether
•    Can only sever if the language requires only an excision, not a substitution of words

Australian National Airways v Cth (1945)
•    Unless an intention affirmatively appears to the contrary, the provisions of a statute are to be taken as independent of one another and not interdependent – following s 15A of Acts Interpretation Act
•    Cth legislation sought to (a) establish an airline; (b) give that airline a monopoly
•    Sections giving rise to (a) were capable of full operation without (b)
•    Therefore the act was severable

Precedent & Overruling

•    Australian courts are bound by decisions of the High Court (stare decisis), except the High Court itself
•    High Court is not bound by its own decisions Engine-Driver’s Case (1913)
•    Court should reconsider previous decision only with great caution and for strong reasons Hughes & Vale Pty Ltd v NSW (1953) per Kitto J
•    Will re-open decision if it involves a question of ‘vital constitutional importance’  Qld v The Cth (1977)
•    Re-open if the decision is manifestly wrong Engine-Driver’s Case (1913)
•    Matters which may justify departure from previous decision Cth v Hospital Contribution Fund (1982)
o    Earlier decision did not rest upon a sound principle expounded in a significant succession of cases
o    Difference between the reasoning of the justices constituting the majority
o    Earlier decision had led to no useful result or considerable inconvenience
o    Earlier decision had not been independently acted on in a manner that militated against consideration
•    High Court should not adhere to precedent to divert it from what it now regards as “the true intent of the statute” John v Federal Commissioner of Taxation (1989)