Cornell Law Review


Patents, Central claiming


The Supreme Court has recently reinvigorated the law of patentable subject matter. But beneath the headlines proclaiming the return of limits to patent eligibility, a more profound shift has taken place: central claiming is reborn.

The Court's eligibility cases are significant outliers compared to today's run-of-the-mill patent law because claim language plays little role in their analyses. In our modern peripheral claiming system, the claim language is the nearexclusive guide to the patent's boundaries. But in its earliest days, our patent system pursued a central claiming approach, in which the inventor's actual work determined the patent's scope. The Court's eligibility cases focus on the inventor's actual contribution to the field, precisely as a central claiming inquiry would. And they can be better understood once this return to central claiming is revealed.

Indeed, the shift to central claiming points the way toward a principled approach to eligibility. The eligibility requirement aims to prevent patents from covering certain kinds of prohibited subject matter: laws of nature, natural phenomena, and abstract ideas. But every invention, at some level of abstraction, applies ineligible subject matter. In a peripheral claiming system, this levels-of-abstraction problem could lead courts to simply deem all claims eligible (as occurred for nearly thirty years) or all claims ineligible (as some fear will happen today). Central claiming offers a solution by focusing on what the inventor added to the storehouse of knowledge. It is that contribution, rather than some abstraction from the claim language, that guides the eligibility analysis.

There are several additional payoffs to uncovering the Court's return to central claiming. It helps make sense of the Court's eligibility jurisprudence, revealing two distinct threads in the cases-one focusing on ineligible contributions and another on implausible contributions-with distinct (though uneasy) normative foundations. More robust use of central claiming might also improve other areas of patent law. As a proof of concept, I show that it could provide a better approach to the exhaustion trigger, improve the law of divided infringement, and rehabilitate the written description requirement. These examples illustrate the potential of the central claiming renaissance.