Of the three bedrock requirements of patentability—novelty, utility, and nonobviousness—the requirement of nonobviousness is the most recent legal development.  Despite its status as a relative newcomer (by a margin of centuries), this requirement is considered essential to the functioning of the patent system—not only in the United States, but in every nation in the World Trade Organization.  This Article takes up the intriguing history of the nonobviousness doctrine, from its antecedents in French and Venetian law to its incorporation into patent systems worldwide.

The case study of the nonobviousness doctrine supplies a launching point for the more ambitious task of investigating the general processes of legal change.  This Article uses the history of the nonobviousness doctrine to reveal the extent to which legal doctrines traverse from nation to nation and the ways in which such doctrines subsequently converge or diverge.  This history also sheds light on how legal documents, legal instruments, and judicial opinions can disguise actual change through clever attempts to parse language and utilize abstract logic, which mask shifts in policy or societal needs.  The Article argues that lack of knowledge of why legal doctrine takes certain forms impoverishes our ability to apply and develop the law intelligently.  Thus, while policy analyses of the law can provide needed insight into legal change, such analyses should move beyond purely positive descriptions of change and engage with normative questions.