Patent Law's Purposeful Ambiguity

27 Pages Posted: 13 Jun 2020

See all articles by Craig Allen Nard

Craig Allen Nard

Case Western Reserve University School of Law

Date Written: 2019


The ambiguity of language is an unremarkable, yet persistent force within our legal system. In the context of patent law, ambiguity presents a particularly acute dilemma; namely, while describing technological innovations is a salient feature of the patent system, affecting the validity and scope of one’s property right, the blunt nature of language makes this task particularly difficult. This paper argues to address this vexing fixture, patent doctrine purposely embraces ambiguity as a linguistic accommodation that provides measured flexibility for actors to claim and describe their innovations. It should not be surprising, therefore, that some of patent law’s most venerable doctrines, such as the requirements for enablement and definiteness reflect this form of ambiguity — two doctrines directly tethered to the disclosure function of patent law.

At first blush, it may seem ironic that purposeful ambiguity would find a home in patent law, given that patent jurisprudence is a property rights regime so closely related to technological fields steeped in empirical certainty. But from a greater remove, ambiguity has an important role in a well-functioning patent system, providing judges, practitioners, and policymakers with room to lithely navigate the ex ante-ex post incentive continuum.

Keywords: Language, Legal Definition, Patent Law, Reasonable Certainty

JEL Classification: K11

Suggested Citation

Nard, Craig Allen, Patent Law's Purposeful Ambiguity (2019). Scheduled for publication in 87 Tenn. L. Rev. 187 (2019), Case Legal Studies Research Paper No. 2020-7, Available at SSRN:

Craig Allen Nard (Contact Author)

Case Western Reserve University School of Law ( email )

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