The majority of the court reversed the decision of the Federal Court and directed the Commissioner of Patents to issue a patent covering claims 1 to 12 of the Patent Application. Speaking for the majority, Rothstein J.A. emphasized the object of the "Patent Act", which is to "promote the development of inventions in a manner that benefits both the inventor and the public." He stated that the Commissioner has no discretion to refuse to grant a patent under s.40 of the Act and if a process or product satisfies the requirements of the Act, a patent must be granted. Additionally, the Patent Act does not explicitly exclude living organisms such as non-human mammals from the definition of "invention." The majority concluded that the oncomouse "must be considered to be the result of both ingenuity and the laws of nature" and is an invention within the meaning of s.2 of the "Patent Act", as it is both unobvious and a new and useful "composition of matter."