disparities and even so was not an absolute nor exclusive statement
of minima, but one subject to a proviso preserving any higher wages
that might be enjoyed. Then the two further steps involved in the
recitals are each challenged. What real bearing, it was asked, has
the reduction of disparities on the continuance of industries and what.
assistance in the re-establishment of servicemen is it to keep women
employed in such industries as the Minister might choose to specify ?
These, no doubt, are formidable criticisms of the amending Regula-
tion. But they are of a nature demanding care and firmness in draw-
ing the line between, on the one hand, the extent and operation or
application of the power, matters which we must decide, and, on the
other hand, the motives or policy actuating its exercise, matters
which are neither our responsibility nor concern. The statement
that it is enough that a parliamentary power of legislation is found to
extend to the subject matter of a law and that the policy or motive
underlying the law does not touch the validity is a commonplace
hardly worth reiteration. But where the legislative power is defined
by reference, in some degree, to purpose, as is the case with the power
to make laws with respect to the naval and military defence of the
Commonwealth, an inquiry whether that is the object of a challenged
law is apt to slide off into considerations of motive and policy.
We are not, it is true, here dealing with the validity of an Act of
Parliament but with subordinate legislation. But it is to be remem-
bered that the authority is confided to the Governor-General in
Council, the Crown, and that, subject to what may appear from any
particular statute as to the grounds for exercising the power it
describes and confers, the reasons why the Crown may have been
advised to adopt the Regulations are, in general, beside the mark.
The risk of being led off into such matters is greater with the
defence power because also of the peculiar lack of fixity of its applica-
tion or operation to support a particular measure. The relation
between the meaning of the power and its application supplies an
instance of a fixed concept with a changing content. As has often
been explained in this Court, what it will enable the Commonwealth
to do at any given time depends upon events. Its very nature
means that its ngth is commensurate with the exigency or
danger which calls for its exercise. Its strength must flow and ebb
accordingly. We have gone through a long conflict against enemies
so strong as to demand the use of every resource we possessed ; so
that the authority of the Central Government under the war power
necessarily became not only supreme but almost total. Its practical
operation must now be measured by a new and different state of fact,
one in which the application of the defence power must be determined