Majority judges Michel, Lourie, & Newman -

The whole purpose of a patent specification is to disclose one's invention to the public. It is the quid pro quo for the grant of the period of exclusivity. The need to tell the public what the invention is, in addition to how to make and use it, is self-evident. One should not be able to obtain a patent on what one has not disclosed to the public.

[I]n whatever form the claims are finally issued, they must be interpreted, in light of the written description, but not beyond it, because otherwise they would be interpreted to cover inventions or aspects of an invention that have not been disclosed. Claims are not necessarily limited to preferred embodiments, but, if there are no other embodiments, and no other disclosure, then they may be so limited. One does not receive entitlement to a period of exclusivity for what one has not disclosed to the public. (I do not here delve into problems of genus-species disclosure, as that is a more complex topic having its own subtleties.) But merely calling an embodiment "preferred," when there are no others, does not entitle one to claims broader than the disclosure.

Dissenting judges Radar & Gajarsa -

The dissenters pointed out that the Lizardtech, Inc. v. Earth Resource Mapping and JVW Enterprises, Inc. v. Interact Accessories cases seemed similar, but resulted in different conclusions.

In both cases, the claims encompass more than the specification expressly describes. In Lizardtech, this court says that a claim scope in excess of the specification’s embodiments invalidates the claim. In JVM, this court says that a claim scope in excess of the specification’s embodiments grants a broader range of infringement. The facts are very similar, the results are not.

The ostensible standard for an adequate written description is that the specification must show “possession” of the claimed invention.

When all else fails, as the new written description test has, consult the statute. The statute sets the standard for measuring sufficiency of disclosure: “The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art . . . to make and use the same.” 35 U.S.C. § 112, ¶ 1. In sum, the statute sets forth the reliable enablement standard to measure sufficiency of disclosure.

Far from explaining a neutral standard for applying written description, Lizardtech seems to fall back on enablement, using the latter as a proxy for the former.

Perhaps even more troubling than its lack of clarity about the proper test for written description, Lizardtech appears to engage in a written description analysis that is not technology neutral. Thus, the opinion explains that the written description requirement prevents an inventor of a specific fuel-efficient engine from generically claiming that engine. The only logical inference that can be drawn from the hypothetical is that claims must not exceed the disclosed embodiments.

This court’s written description jurisprudence has become opaque to the point of obscuring other areas of this court’s law.

As to opinion - one the one hand, while the dissent makes some good points, it overstates the murk. On the other hand, there's murk.

Patent litigants often don't know how a court would rule, in a variety of ways, from claim construction to acceptable claim scope, and so litigate until rulings put some clear writing on the wall, or the possibility of changing the writing on the wall is exhausted. The litigation drive to exhaustion is fueled by the stakes involved in patent cases.

Specific to LizardTech, the majority opinion is not injudicious. In the invalidated claim (21), LizardTech disclosed only one embodiment that didn't generically solve the tackled problem, yet drafted a genus claim - that's overreaching.

Courts are always looking for a bright line rule-of-thumb to apply; some way to create a simple formula. That's particularly difficult with some aspects of patents, which are, ultimately, claims of technological prowess. Judging such prowess with regard to claim scope is likely to continue to result in rulings that may make sense in context of the specific case and technology, but seem inconsistent if viewed purely from a standpoint of consistency in legal precedent. Given the inherent complexity of radically different technologies, a simple legal bright-line rule may be insensible.