Lefstin on the History of "Inventive Application"

Jeffrey A. Lefstin, University of California Hastings College of the Law, has posted Inventive Application: A History.  Here is the abstract:

As the Supreme Court prepares to take up yet another case on the doctrine of patent-eligible subject matter, the Court will again be called on to draw the line between unpatentable fundamental principles and patentable inventions. The most significant question facing the Court is not whether software is patentable, but whether that foundational boundary requires an “inventive application,” as suggested by the Court in Mayo v. Prometheus. Both Prometheus and its intellectual forebear, Parker v. Flook, drew this notion in part from Neilson v. Harford, the famous “hot blast” case decided by the Court of Exchequer in 1841.

But an examination of Neilson reveals a different story than the one told by the Supreme Court. Neilson was indeed the starting point from which 19th-century courts, both English and American, drew the boundary between discovery and invention. But the patent in Neilson was not sustained because it represented an inventive application of the patentee’s discovery. It was in fact sustained because the patentee’s application was entirely conventional and routine. Nineteenth century English courts and commentators understood Neilson and its companion cases to teach that while discoveries in the abstract were not patentable, a practical application of a new discovery was patentable regardless of the novelty or inventiveness of the application.

The same understanding prevailed in the United States. Neilson remained the starting point for discussions of patent-eligible subject matter, patent scope, and the patentability of processes, but 19th century case law did not demand inventive application. The 19th century treatise-writers addressed the question directly, and reached the same conclusion as their English counterparts: practical application of a discovery sufficed. And until 1948, the weight of American authority agreed.

It was then that Justice Douglas, in Funk Brothers v. Kalo Inoculant, first drew boundary between discovery and invention at inventive application. Largely forgotten today, the lower courts’ implementation of Funk is a cautionary tale of the patents that could be invalidated if the Court maintains inventive application as a test of patent eligibility.