In Ariad v. Lilly, defenders of the written description requirement made two primary arguments: (1) that the text of the Patent Act and the accompanying jurisprudential history lead to the conclusion that the statute creates a separate written description requirement; and (2) that the written description requirement serves an important role in policing applicant behavior. An en banc Federal Circuit confirmed that the written description requirement is separate and distinct from enablement, but firmly based its decision on the first argument rather than the second. I believe that the Federal Circuit took the correct approach – especially in its substantial rejection of the second argument. In my recent essay, I wrote that – apart from its value in "new matter" rejections – the role of the written description requirement in ex parte prosecution is negligible. See An Empirical Study of the Role of the Written Description Requirement in Patent Prosecution, 104 NORTHWESTERN UNIV. L.R. Colloquy ___ (2010) (ssrn download). In that essay, I took no position on the larger issue of whether the written description doctrine is nevertheless required by the statute.
In his concurring opinion, Judge Gajarsa explicitly rejects the argument that the written description requirement is a necessary on policy grounds – writing that "[t]he empirical evidence confirms my belief that written description serves little practical purpose as an independent invalidity device [apart from policing priority]." Despite the lack of a policy justification, Judge Gajarsa concurred with the judgment "because the majority's opinion provides a reasonable interpretation of a less than clear statute."