Dynamic Claim Interpretation

Abstract

Patent law hinges on the interpretation of a legal text, on construing the definitional claims that conclude the patent document, demarcating the characteristic features of the invention. Courts routinely construe the claims to determine questions of scope, of infringement, of validity, all of which are assessed in reference to the textually claimed invention. Not surprisingly, this interpretive exercise closely parallels common law interpretation of other legal texts, often encompassing familiar methodologies such as the application of competing canons of construction, reliance on dictionary definitions, and searching the documentary history for clues as to its original meaning. But, despite such parallels, surprisingly little of the vast literature on textual interpretation has been brought to bear on patent claim interpretation. In this chapter, I look to the interpretive principles laid out in William Eskridge’s landmark work Dynamic Statutory Interpretation for guidance in approaching claim construction. In particular, I critique the noted tendency of the United States Court of Appeals for the Federal Circuit to adopt formalist approaches to textual interpretation; as Eskridge noted more than a decade ago, formalism is merely interpretive purpose veiled behind claims of neutrality and determinism. As such, interpretive formalism subordinates legal functionality in order to maintain a facade of inevitability. Courts reviewing patent claims might do better to adopt realist approaches akin to Eskridge’s “dynamic statutory interpretation” in order to effectuate the proper function of claims in the patent system.