St Catherine’s Milling may seem like a peculiar choice as one of the three constitutional cases that helped to define Canada as a nation, given that most of the legal principles affirmed by Lord Watson, writing for the Privy Council, have been overruled. This paper identifies the principles from St Catherine’s Milling which are still good law, and argues that the logic that underlies and shapes those principles is the logic of the doctrine of discovery and the principle of terra nullius.
Jurists have articulated different versions of the doctrine of discovery and disagreed about its precise requirements. At its essence, the doctrine allows a nation to acquire sovereignty over foreign territory by being the first to discover it; on some versions, it was necessary to not only discover but also effectively occupy the territory. Traditionally, this mode of acquiring sovereignty applied only to terra nullius, that is, territory not yet possessed by a socially and politically organized community. Some European nations, however, deemed Indigenous territories to be terrae nullius for the sake of asserting sovereignty over them by means of discovery. Their rationale was the supposed inferiority of Indigenous peoples