This article explores the proper scope of judicial power in patent law by focusing on the Federal Circuit's theories of claim interpretation. A study of the court's claim interpretation jurisprudence reveals two schools of interpretation. I characterize these approaches as (1) hypertextualism, which is the predominant interpretative theory; and (2) pragmatic textualism, which is gradually asserting itself. The hypertextualist judge has an expansive view of judicial power, characterizing claim interpretation as a question of law subject to de novo review. This highly formalistic approach stresses textual fidelity and internal textual coherence, but eschews extrinsic evidence as an interpretive tool, portraying its use as "rarely, if ever," proper. Although hypertextualism posits that expert testimony may be used if the intrinsic record is ambiguous, a hypertextualist judge rarely finds ambiguity. If ambiguity is found, expert testimony may be used to educate the judge in the relevant technology ? not for the purpose of interpreting the ambiguous claim language.

On the other hand, the pragmatic textualist approach, while embracing the importance of textual fidelity and internal coherence, also emphasizes the relevance of extrinsic context and industry custom, of which patent law's "person having ordinary skill in the art" is representative. This hypothetical artisan is one of the cynosures of our patent system and is valued by the pragmatic textualist as an interpretive tool because the artisan has knowledge of the underlying assumptions present in his technological community and is sensitive to the facts on the ground. This article asserts that unlike hypertextualism, a pragmatic textualist approach is consistent with legal and hermeneutic philosophy?the work of Posner, Easterbrook, and Wittgenstein, in particular?and is more sensitive to patent law's incentive dynamic and post-innovation practice.

Therefore, this article is skeptical of hypertextualism as a theory of claim interpretation and argues that it ultimately cannot deliver on its promise of greater certainty and uniformity. As such, this article urges the Federal Circuit to adopt a pragmatic textualist approach.


Patent Law, Judicial Decision Making

Publication Date


Document Type


Place of Original Publication

Harvard Journal of Law & Technology

Publication Information

14 Harvard Journal of Law & Technology 1 (2000)


COinS Craig Allen Nard Faculty Bio