Ontario appealed to the Privy Council by arguing: The Board ruled: Lord Watson held that the federal government's residual power allowed it to enact laws that "ought to be strictly confined to such matters as are unquestionably of Canadian interest and importance and ought not to trench upon provincial legislation with respect to any of the classes of subjects enumerated in section 92."

If it were once conceded that the Parliament of Canada has authority to make laws applicable to the whole Dominion, in relation to matters which in each province are substantially of local or private interest, upon the assumption that these matters also concern the peace, order, and good government of the Dominion, there is hardly a subject enumerated in s. 92 upon which it might not legislate, to the exclusion of the provincial legislatures.Lord Watson formulated a situation in which the residual power could be applied in what would become known as the "national dimensions doctrine."

[8]There has been controversy as to whether it was necessary for Lord Watson to have issued such a broad ruling in this case, and to have defined the federal trade and commerce power in such a restrictive way.

[9] It has been suggested that it arose from the views of John Locke on economic liberalism, popular in the 19th century,[10] according to which the power of the state should be focused on ensuring, by regulation, that property is being used productively.

The "national dimensions doctrine" was largely ignored for the following 40 years until it arose in its modern form in Ontario v. Canada Temperance Federation.