These matters are only preliminary to the questions that arise under federal constitutions, but they are necessary to be understood if we are to avoid confusion. In the case of a federated Dominion within the British Empire the federal constitution is itself an Act of the Imperial Parliament, and therefore all exercise of legislative power in the Dominion, whether by the central legislature or by that of any constituent State or Province, must be consistent with its provisions, or otherwise it will clearly be invalid to the extent of the repugnancy or excess. Every such constitution has to assign the bounds of central and local legislation; in the case of Canada, for example, the field of action open to the Dominion Parliament at Ottawa and the legislatures of the several Provinces. In strict legal theory the Confederation Act of Canada or the Commonwealth Act of Australia can be amended at Westminster like any other Act of Parliament; but, as in fact these constituent Acts were framed by Canadian and Australian statesmen, so it is well understood that the Home Parliament will not touch them except at the request of Canada or Australia. With such request, there have been amendments and legislative interpretations of the Canadian Constitution. If any Act of Parliament might be called unconstitutional, uninvited intermeddling with the constitution of a self-governing colony would be so. We may pause here to draw one immediate consequence. Whenever Home Rule is enacted and established for Ireland, Parliament must harden its heart against all endeavours, from whatever quarter they may proceed, to obtain any alteration in the scheme save as it may be required by the regularly expressed will of Ireland as a whole. This should be an understanding outside and above all party divisions, British or Irish; and it is equally necessary whether or not a certain number of Irish members continue to sit at Westminster.
We now turn to the possible conflicts of legislation under a federal constitution. It will be convenient to use the more expressive and generally understood word “State” for the autonomous components of the federation. The Canadian term “Province” is prior in time within the Empire; but it might be misleading to readers unacquainted with Canadian affairs, as tending to suggest merely administrative functions like those of a County Council: a body which has many important duties and some delegated legislative authority, but cannot reasonably be called autonomous. A federal constitution must assign some legislative powers exclusively to the federal legislature, and it may reserve or assign others exclusively to the State legislatures. It may also leave a region in which the States have power to legislate, but subject to a concurrent and superior power in the federal authority. This is actually the case in Canada. Hence questions may arise of a more complicated kind than those which are open under unitary Home Rule; they may nevertheless be instructive in simpler cases. The Judicial Committee has deliberately abstained from laying down any general system of interpretation or any presumption in favour of extending or limiting the powers of either Federal or State legislation. It is prepared to take some pains to reconcile apparently conflicting enactments, but beyond that no precise method can be formulated. The Court must deal with the problem of each case on its own merits. “The true nature and character of the legislation in the particular instance under discussion must always be determined in order to ascertain the class of subject to which it really belongs.”(79) Again: “In performing this difficult duty, it will be a wise course for those on whom it is thrown to decide each case which arises as best they can, without entering more largely upon an interpretation of the statute than is necessary for the decision of the particular question in hand.”(80) It would seem obvious without argument that the courts of Canada, Australia, or in the future, Ireland, cannot be bound in any case to give effect to two conflicting enactments of the local and the central legislative bodies at once, notwithstanding that some of the language used by the Judicial Committee a few years ago, on an appeal from the Supreme Court of Victoria, suggests that there is no authority anywhere, short of an Act of the Imperial Parliament, capable of resolving such a contradiction.(81)