A. INTRODUCTION
             Sir John A. Macdonald believed that the Constitution Act, 1867, had been drafted in such a manner as to ensure that "'all conflict of jurisdiction' had been avoided" and that the courts would therefore assume a relatively minor role in the evolution of Canadian federalism. [Note 1: As quoted in W.P.M. Kennedy, "The Interpretation of the British North America Act" (1943) 8 Cambridge L.J. 146 at 151.] Sir John A.'s prediction proved to be wildly off the mark. In part this change was a product of the fact that the language used in the 1867 Act, although apparently clear to its drafters, turned out to be ambiguous and open ended in practice. But, more significantly, the division of responsibilities envisaged by the drafters of the 1867 Act was structured to respond to an era in which government played a modest and limited role. Within a matter of decades, the entire conception of the role of the state in Canada had changed, with governments being called upon to intervene in areas !
             of economic regulation and social policy that were simply unknown in 1867. The drafters of the 1867 Act had failed to address the question of how these new roles and responsibilities should be shared between different levels of government because, for them, it was unimaginable that governments would be required to exercise such powers.
             It fell to the courts to legislate a division of powers for Canada. In performing that function, the courts would certainly structure their decisions in accordance with the categories set out in sections 91 and 92 of the Constitution Act, 1867. But those categories merely provided a framework within which the legislative activity of the courts would be performed, as opposed to dictating the outcomes of what was an essentially creative process.
             Before 1949, the highest legal authority in terms of the Canadian constitution was the Judicial Committee of the Privy Council ...