The doctrine of equivalents may not be used to cover unclaimed subject matter disclosed in a US patent application. This was the holding of the Court of Appeals for the Federal Circuit (sitting en banc), in Johnson and Johnston Associates, Inc v RE Service Co (62 USPQ 2d 1225(March 28 2002)). This conclusion was contrary to the Supreme Court's majority opinion in Graver Tank & Mfg Co v Linde Air Products (339 US 605, 609 (1950)).

The decision itself is rendered per curiam, but in four separate concurring opinions ? written by four separate members of the court, all but one of which is joined by from one to four non-author members ? various justifications for the per curiam result are advanced. The lengthy dissent by Judge Pauline Newman forcefully criticizes the majority's creation of "a new, unnecessary and often unjust, per se rule"(62 USPQ2d at 1237) which is "in egregious conflict with the Supreme Court's decision in Graver Tank [cited above] ... and Warner-Jenkinson Co v Hilton Davis Chemical Co (520 US 17 ... (1997))" (Id at 1238), adopts the positions of the dissenters in Graver Tank, supra (Id), and is in derogation of stare decisis (ie the duty of an inferior court under at least US and UK law to follow precedents established by its superior court) (Id)

The majority's per curiam opinion once again reveals the discomfort of most of the Federal Circuit with the doctrine of equivalents. The doctrine extends back to at least 1850 and is rooted in equity rather than in the interpretation of statutory law. While acknowledging that the Supreme Court in Graver Tank, supra, observed that "equivalency must be determined against the context of the patent, the prior art, and the particular circumstances of the case," the per curiam majority immediately departs from this rubric to construct a theory that is not expressed anywhere in Graver Tank and appears, at best, to be extremely far-fetched. Reverting to claims held invalid in a previous Supreme Court consideration of the same patent that was involved in its 1950 Graver Tank opinion (Graver Tank & Mfg Co v Linde Air Products (336 US 27 (1949)), often referred to as Graver I) the Federal Circuit majority's per curiam opinion hypothesizes that the manganese silicate held in the second Graver case to perform "substantially the same function in substantially the same way to obtain the same result" (339 US at 608) as alkaline earth metal silicates in certain welding compositions (and hence their equivalent for infringement purposes) was so accepted because the patentee had covered the use of manganese silicate (a non-alkaline earth metal compound) in similar welding compositions in the broader, earlier invalidated, claims and hence had not dedicated this embodiment to the public.

Five judges of the Federal Circuit signed an opinion written by Judge Clevenger stating that the per curiam opinion does not announce a new rule, is not "mutinous" in light of the 1950 Graver Tank decision (62 USPQ2d at 1231) and "for reasons stated in the opinions for the court and by Judge Dyk"(Id) is not inconsistent with Graver Tank.

Judge Rader, joined by Chief Judge Mayer, chose to rationalize the per curiam opinion by introducing a reinterpretation of the doctrine of equivalents as a doctrine that "does not capture subject matter that the patent drafter reasonably could have foreseen during the application process and included in the claims" (69 USPQ 2d at 1231). The entire opinion appears at 1231-1234.

Judge Dyk, joined by Judge Linn, fashions a hypothesis that the Supreme Court majority in Graver Tank considered that the question of dedication by disclosure was not properly before it because of a conflict between the opposing parties about how to construe the patent disclosure and hence left the dedication question open (69 USPQ2d at 1234-6). The majority Supreme Court opinion, however, says nothing one way or the other, to support this hypothesis.

Judge Lourie, writing separately, expresses valid concerns to support his "serious doubts" that the foreseeability principle espoused by Judges Rader and Mayer is a valid or workable basis for rationalizing the decision of the Federal Circuit majority with the doctrine of equivalents. In particular, and with substantial justification, he foresees a likely probability of great confusion between "foreseeability" as explained in their opinion and the determination of what would have been obvious to one of ordinary skill in the art at the time the invention was made under 35 USC 103.

The Federal Circuit majority's discomfiture with the doctrine of equivalents has been quite evident since its own Warner-Jenkinson en banc opinion (35 USPQ 2d 1641 (Fed Cir 1995) which the Supreme Court in Warner-Jenkinson, supra, duly unanimously reversed. This discomfiture was further highlighted by the Federal Circuit's en banc opinion in Festo Corp v Shoketsu Kinzoku Kogyo Kabushiki Co (56 USPQ 2d 1865 (Fed Cir 2000)), the outcome of which is sub judice in the Supreme Court at the time of writing.

While it is not entirely clear that the Federal Circuit majority is itself dedicated to abolishing that doctrine, it is certain that they would not mourn its loss, were it somehow scuttled by Congress or the Supreme Court. The reason for this mindset is difficult to fathom.

Equity, which spawned the doctrine of equivalents, arose historically in England because adherence to the strict letter of statutory law, and even of established common law principles, at times produced unjust results. The specific justification for the doctrine of equivalents set out in 1850s and 1860s Supreme Court cases was that of preventing copyists from perpetrating a fraud on a patent by treading so close to what the patent clearly covered as to take full advantage of the very heart of what had been invented. The need for the doctrine is arguably much more pressing today, where the content of patent claims is more strictly cabinned by statute, Patent and Trademark Office rule and precedent than it was in 1850. Circuit Judge Newman's dissent (62 USPQ at 1243) in essence warns that the trend of viewing the patent claim as a straitjacket on the patentee is likely to inhibit further technological innovation. She concludes: "A judicial change in the balance between innovator [patentee] and imitator [infringer] should not be made in disregard of consequences. The neatness of a per se rule is not necessarily sound legal or economic policy. Nor is it sound judicial policy, for ... this case raises questions of fundamental fairness as to the dispute that will now be excluded from judicial review" (Id).

Fairness, of course, is the essence of equity and equity arose centuries ago and still importantly persists in UK and US jurisprudence because per se rules are not, in every case, fair. In certain ways, the continued importance of equity in US law generally is a safety valve against the tyranny that strict adherence to rigid rules would otherwise foster. Indeed, if black letter law and per se rules are regarded as epitomizing justice in the modern world, then equity is akin to the mercy that "seasons justice" as Shakespeare so eloquently teaches in The Merchant of Venice.

Whether a Supreme Court review of Johnson and Johnston Associates will be sought is unknown and may depend to some extent on the content of the awaited Supreme Court decision in Festo. Whether or not certiorari is sought or, if so, granted in this case, the increasing Federal Circuit tendency toward legislating by judicial fiat instead of sticking to the judicial function of interpreting existing law should be of serious concern to other branches of the US government and knowledgeable members of the public.

Mary Helen Sears