joining as to Appeal No. 83-781 and dissenting as to Appeal No. 83-720.
I agree with the opinion and the result in Appeal No. 83-781, as well as with the holding that our jurisdiction over both appeals has already been decided. I dissent from the opinion and result in Appeal No. 83-720.
My view of 35 U.S.C. § 291 is that the district court’s jurisdiction under that provision1 does not depend upon the actual existence (as finally determined by the court at the time of decision) of two interfering patents but rather depends on a good faith, non-frivolous and substantial assertion of such interference by the plaintiff. That is the general method for determining other requirements for federal jurisdiction (e.g., federal questions, diversity of citizenship, amount). Ralston Steel Corp. v. United States, 340 F.2d 663, 666-669, (Ct.Cl.), cert. denied, 381 U.S. 950, 85 S.Ct. 1803, 14 L.Ed.2d 723 (1965);2 Moore’s Federal Practice, pars. 0.91[3], 0.92[1], 8.11. I see no adequate reason for departing from that overall principle or for holding that § 291 requires actual interference (at the time of decision) before jurisdiction is acquired. The majority’s holding calls for a preliminary trial and decision on that issue before the district court has jurisdiction to consider whether one of the alleged*765ly interfering patents is invalid;3 if the first trial on jurisdiction results in a determination of actual interference there will have to be a second trial on the issue of validity. Neither the language nor the history of § 291 requires that special, wasteful procedure with respect to this particular jurisdictional provision.
The court’s opinion suggests that the only alternative to its construction calling for actual interference is that federal jurisdiction to pass on validity under § 291 follows upon a mere allegation of interference. That is not the federal jurisdictional principle, nor is it my position. The proper rule (as I see it) is that there must be a good faith, non-frivolous, substantial assertion of interference — the type of assertion which can be preliminarily tested (without full trial) by the parties and the court to see whether that standard is met. This would plainly be no counterpart to a foreign “nullity action”, as the majority fears, but rather a counterpart to the very common claim or counterclaim (in this country) for a declaratory judgment of invalidity.4 Moreover, this interpretation of § 291 would not only accord with general principles of federal jurisdiction but would also supply a ready test for deciding whether the district court possesses jurisdiction over such an interference case under § 291.
Even if there has to be an actual interference at the beginning of the suit, I cannot agree that the defendant can destroy jurisdiction (as is said to be true here) simply by disclaiming the claims of his patent which create the interference. That would allow the defendant to destroy jurisdiction whenever he deems it convenient, and turns drastically away from the normal rule that federal jurisdiction is measured at the outset of the suit.5 And if § 291 does no more than create a claim when jurisdiction is otherwise present, my view is that the section establishes a right to pursue a claim of invalidity, not only when there exist actual interfering patents, but also where there is a substantial, good faith claim of interference at the time suit is brought. The statutory direction to consider invalidity (on any ground) “in whole or in part” (see footnotes 3 and 5, supra) seems to me to point in that direction.
In my view, this case (No. 83-720) must be remanded. The trial judge has made no finding that the initial summary assertion of interfering patents was made in good faith, and was substantial and non-frivolous, or that the disclaimer of three claims of the Porter patent in No. 83-720 was not made in good faith but to avoid § 291. I would return the case so that those issues can be considered; if the answer is affirmative, I would hold that the court has and has had jurisdiction to decide the validity of the Porter patent.
. I need not decide definitively whether § 291 is a jurisdictional provision at all, or whether, as Judge Smith would hold, the only relevant jurisdictional provision is 28 U.S.C. § 1338. In either event (in my view) the result here should be the same.
. Ralston was a case in which the jurisdiction of the Court of Claims was closely entwined with the merits and yet the court applied the general rule. Contrast footnote 4 of the majority opinion.
. The language of § 291 indicates clearly that Congress fully opened up the question of validity and did not restrict it solely to the issue of priority.
. The counterpart is that, instead of a substantial claim that one may be held to have infringed, § 291 requires a substantial claim that the patents do interfere.
. The court’s construction on this point seems to me to conflict with the plain intention of § 291 to allow the interfering patents to be held invalid on any ground. See fn. 3, supra.