Expectations of the global harmonization of patent law are commonplace in legal literature. Historical writing on national patent systems, however, reveal their persistent specificities to national economic and cultural needs. These two narratives are not easy to reconcile, and the cessation in 2010 of the World Intellectual Property Office’s efforts to reconcile patent laws suggests that the diversity is the prevalent phenomenon. The reasons for this include the diverse rationales of patents in terms of: the “natural” rights of inventors; the social rewards for useful inventions; investments in the risky future of industrial progress; and the incentives required to encourage inventors to share private knowledge. Compounding this complexity is the way that historically libertarian cultures have privileged the rights of the inventor, whereas cultures cherishing strong government have focused on the needs of the state. While some systems have focused on the importance of novelty, others have focused on the utility of an invention – and not all national Patent Offices are formally required to examine patent applications for such qualities. The resilient diversity of patent systems can thus be understood as part of a multiplicity of contingent “social contracts” of protecting invention that are subject to local more than global forces.