in whole or in part, directly or indirectly, of full enjoyment of the monopoly as conferred by law. Monsanto Canada Inc. v. Schmeiser sets a very high bar for a defence based on these terms, as possession of the invention leads to an rebuttable presumption of use. The presumption can be rebutted if the defendant can show that they genuinely did not intend on using the patented invention. For example, in British United Shoe Ministry v. Simon Collier Ltd., the patented invention was a part of a machine which the defendant bootmaker had removed and set aside. It was possible to run the machine without using the patented part, and the defendants willingly returned the patented invention when action was commenced. If the patented invention occurred as an intermediary of a process or the patented process occurred outside of Canada, patent infringement may still be found. A court should consider the following factors in determining whether there has been infringement in these cases: The importance of the process or intermediary to the final product sold in Canada; Whether the final product contains all or part of the patented product; The stage at which the patented product or process is used; The number of instances of use made of the patented process or object; The strength of the evidence indicating that if the process or intermediary had occurred in Canada, the product or process would constitute infringement. In a case of secondary infringement or inducement, the plaintiff patent holder would need to show: Primary infringement from the direct infringer; Influence from the seller to engage in infringement, to the point where without the influence there would have been no infringement; The influence was knowingly exercised by the seller. A successful defence could be based on any of these grounds in the case of secondary infringement or inducement. Gillette defence The Gillette defence is a way of arguing non-infringement by proving invalidity without requiring the patent claims to be construed. The defence is based on an early 1900s decision from the House of Lords and allows the defendant to plead that their alleged infringing actions are part of the prior art, and thus either the patent is invalid for claiming the prior art or if the patent is valid, the defendant does not infringe. In view of the Supreme Court's decision in Free World Trust, any Gillette Defence would still require that