Prometheus Laboratories, Mental Steps, and Printed Matter


This article identifies connections between the Supreme Court’s recent opinion in Mayo Collaborative Services v. Prometheus Laboratories and two doctrines that federal appellate courts have used to curb the reach of patent protection: the historical mental steps doctrine and the contemporary printed matter doctrine. These connections suggest a new way of thinking about what the Court is doing in its Prometheus Laboratories opinion. On its rhetorical surface, the opinion clearly addresses the role that “laws of nature” have long played in restricting the reach of patentable subject matter. However, beneath its laws-of-nature rhetoric, Prometheus Laboratories can also be construed as a case that explores the impact of the unpatentability of the human mind on the reach of patent protection. The Court’s Prometheus Laboratories opinion resonates strongly with both historical limits on the patentability of newly invented mental processes (mental steps) and contemporary limits on the patentability of information that is meaningful to the human mind (printed matter).