$34 THE FEDERATIONS AND THE UNION [PART IV
render the analogy of the United States Constitution a very
slender one.!
Moreover, the natural interpretation of the Commonwealth
of Australia Constitution Act is the one placed upon it by the
Privy Council, and the interpretation of the United States
Constitution is admittedly not a natural one, but one which
has been rendered necessary in order to preserve the federation
 at all in view of the rigidity of the Constitution. The
doctrine of necessary implication must therefore be regarded
as still open to grave doubt as a permanent rendering of the
Constitution of the Commonwealth, for it has been held by
Isaacs J.2 that the view laid down by the Privy Council, that
the doctrine is not a part of the Commonwealth Constitution,
is not merely sound in law, but is binding as a pronouncement
on principle of a superior Court on the High Court of the
Commonwealth, and Higgins J. holds the same view but in
a stronger form, for he thinks that in all cases the High
Court should follow the judgements of the Privy Council,
whereas Isaacs J. holds that in cases coming within s. 74 of
the Constitution the High Court is entitled to come to what
decision it thinks fit without regard to a decision on the same
matter of the Privy Council. Isaacs d. maintains, therefore,
the doctrine that the states cannot interfere with a Commonwealth
 instrumentality, but in the form in which he upholds
this view little exception need be taken to it, for he has
declined to see in any ordinary legislation an interference
with a Commonwealth instrumentality, and it may well be
that even the Privy Council would decline to uphold the
authority of legislation which aimed directly at interference
with the Commonwealth. That is a very different principle
trom adopting an interpretation of the Constitution such as
! The constant doctrine of the sovereignty of the states is really an echo
of the Amorican doctrine; but there is the serious difference that the
Colonies were never sovereign at all in any strict sense, while the states
of the Union were once sovereign and the powers retained are remnants
of that sovereignty. To use sovereignty to cover internal autonomy is
hardly a convenient use of the phrase.
s fluddart Parker & Co. Provrietary Ltd. v. Moorehead, 8 Cc. LR
330, at pp. 387. 390.