In a new essay for the Patently-O Patent Law Journal, Donald Chisum considers the "invention priority principle" and its role in the written description analysis.
Cite as Donald S. Chisum, Written Description of the Invention: Ariad (2010) and the Overlooked Invention Priority Principle, 2010 Patently‐O Patent L.J. 72.
There may be a solution: application of an established patent law priority principle. The principle focuses on a specific embodiment of a generically claimed invention as a constructive reduction to practice, that is, as a completion of the inventive process. Adopting this solution would preserve the written description of the invention's (WDIs) independence and applicability to original claims but would remove WDI as a standard for assessing the scope of a patent claim. WDI would continue to govern whether, at the time an applicant files an application, he or she has completed the inventive process, that is, "possesses" the invention. But only enablement would govern how broadly the applicant is entitled to claim that invention. It may be possible to implement this priority principle interpretation of Ariad without contradicting its clear holdings.