dissenting.
Without the benefit of full briefs and arguments I would not answer the question whether the First Amendment requires that obscenity be proved beyond a reasonable doubt in *95a public nuisance abatement action.1 Justice Brennan’s opinion in McKinney v. Alabama, 424 U. S. 669, 683-687, in which Justice Stewart and Justice Marshall joined, demonstrates the substantiality of the question. It is distressing to find that the Court considers novel questions of this character so easy as not even to merit argument.2 It is also surprising to find the Court reaching out to decide such a question when its jurisdiction to do so is doubtful and when the absence of conflict on the question normally would call for a routine denial of certiorari.
I
In this public nuisance abatement action the California Superior Court and the California Court of Appeal concluded that obscenity must be proved beyond a reasonable doubt. See People ex rel. Gow v. Mitchell Brothers’ Santa Ana Theater, 114 Cal. App. 3d 923, 935-937, 171 Cal. Rptr. 85, 92-93 *96(1981). Without deciding whether the First Amendment imposes any special standard of proof on the censorship of allegedly obscene materials, the Court today opines that proof beyond a reasonable doubt is not constitutionally required. The Court has no jurisdiction to express that opinion unless the California courts imposed that standard because they understood it to be required by federal law. It is by no means clear that they did so.
State courts surely know the difference between opinions that merely contain persuasive reasoning and opinions that are authoritative because they explain a ruling that is binding on lower courts. Moreover, absent a definitive ruling from a higher tribunal, state courts are entitled to fashion state rules of procedure to govern the conduct of civil trials in state courts. Until today, this Court has never expressed an opinion on the standard of proof that a trial court should impose on a civil litigant seeking to prove that a motion picture film is obscene.
The explanation by the California Court of Appeal of its ruling on the standard-of-proof issue does not indicate that the court considered itself bound to follow any decision by this Court. As the Court of Appeal explained, the trial judge “established the high burden of proof based on the reasoning of Mr. Justice Brennan’s concurring opinion in McKinney v. Alabama, supra, 424 U. S. 669, 678.” Id., at 935, 171 Cal. Rptr., at 92. After citing People v. Frangadakis, 184 Cal. App. 2d 540, 550, 7 Cal. Rptr. 776, 782 (1960),3 and rejecting the City Attorney’s argument that the standard of proof required in normal public nuisance abatement actions should be applied in an obscenity case, the California Court of Appeal stated that it “agree[d]” with the burden of proof portion of Justice Brennan’s opinion and found one passage *97“particularly persuasive.” 114 Cal. App. 3d, at 936, 171 Cal. Rptr., at 93.4
The state court’s opinion may be construed in either of two ways. On the one hand, because the Court of Appeal agreed with the reasoning in Justice Brennan’s opinion, it may merely have established the procedural rule to be followed in the state courts subject to its jurisdiction.5 On the other hand, it may have assumed that a lesser burden would have complied with state law but nevertheless ruled as it did because it believed the Federal Constitution required that result. When this sort of ambiguity is present, our jurisdiction is doubtful and we have a duty to withhold decision on the merits until we are able “to say with requisite assurance that this Court has jurisdiction in the premises.” Mental Hygiene Dept. of Cal. v. Kirchner, 380 U. S. 194, 196.
As Justice Harlan emphasized in that case:
“This Court is always wary of assuming jurisdiction of a case from a state court unless it is plain that a federal *98question is necessarily presented, and the party seeking review here must show that we have jurisdiction of the case. Were we to assume that the federal question was the basis for the decision below, it is clear that the California Supreme Court, either on remand or in another case presenting the same issues, could inform us that its opinion was in fact based, at least in part, on the California Constitution, thus leaving the result untouched by whatever conclusions this Court might have reached on the merits of the federal question.” Id., at 197 (footnote omitted).
Later in the opinion, Justice Harlan emphasized that we must be able to say with “certainty that the California judgment rested solely on [a federal ground],” id., at 200 (emphasis in original), before we may take jurisdiction of a case coming from a state court.
Unless a case presents a question of unusual importance, jurisdictional doubt of this character normally leads to the dismissal of the writ of certiorari as improvidently granted, or to its denial if the petition is still pending. Id., at 200-201. If the issue is sufficiently important, our practice is to remand to the state court to make sure that its decision rested solely on a state ground before we proceed further. See, e. g., California v. Krivda, 409 U. S. 33. Whether one regards this as an important or an unimportant case, surely we should not simply ignore the customary restraints on the exercise of our limited jurisdiction over state courts.
II
Entirely apart from the jurisdictional question, adherence to the Court’s traditional practice of avoiding the unnecessary and premature adjudication of constitutional questions counsels denial of this certiorari petition. As a practical matter, what is at stake is the City Attorney’s request for a retrial of the question whether 17 rather than just 11 motion *99picture films are obscene. No conflict between the ruling of the California Court of Appeal and that of any other court has been called to our attention. Even if one intermediate appellate court has given greater constitutional protection to some citizens of California than this Court would require, that is hardly a sufficient reason for reviewing the state court’s decision.6 No pressing need for the exercise of our jurisdiction at this time is apparent to me.
Accordingly, I respectfully dissent from the decision to grant certiorari and to decide the case summarily.
Cf. Snepp v. United States, 444 U. S. 507, 516 (Stevens, J., dissenting).
When the State prohibits its citizens from purchasing books they want to read or entering theaters to view motion pictures they want to see, it engages in a form of censorship. The task of the censor cannot be performed without examining the content of the communication under scrutiny. Although a majority of the Court has stoutly and repeatedly denied that government has any power to draw distinctions based on the content of any expression, see the separate opinions in FCC v. Pacifica Foundation, 438 U. S. 726, and in Young v. American Mini Theatres, Inc., 427 U. S. 50, today the Court holds that the California courts were unnecessarily concerned that the censor’s content-based scrutiny might result in the prohibition of protected communication. The holding seems to rest on an assumption that, no matter what the consequences of a civil lawsuit may be, the Constitution does not require the plaintiff to satisfy the reasonable-doubt standard of proof. If the Court is endorsing that broad assumption today, then this decision is far more important than even the substantial question presented for review would indicate. If the Court does not intend to endorse such a broad premise, its opinion should respond to the arguments advanced by Justice Brennan, Justice Stewart, and Justice Marshall in McKinney.
In that case the court held that the standard of proof in an action to abate a public nuisance under California Business and Professional Code § 25604 is by a preponderence of the evidence.
Contrary to the Court’s characterization, ante, at 92, the Court of Appeal did not hold that Vance v. Universal Amusement Co., 445 U. S. 308, compelled its conclusion “that one of the required procedures is that obscenity be proved beyond a reasonable doubt.” 114 Cal. App. 3d, at 936, 171 Cal. Rptr., at 93. Rather, the court cited and quoted from Vance in the course of its rejection of the city’s argument that a statement towards the end of this Court’s long opinion in Mugler v. Kansas, 123 U. S. 623, 673, “support[s] its position that the burden of proof should be by ‘clear and convincing evidence.’” 114 Cal. App. 3d, at 935, 171 Cal. Rptr., at 92. Since the argument based on Mugler is meritless, it is a mistake to attach undue significance to the court’s response to that argument.
The reasonable-doubt standard is no stranger to civil litigation. See, e. g., cases cited in 9 J. Wigmore, Evidence § 2498, nn. 2-12 (J. Chadbourn rev. 1981). This Court has even used the standard in several civil contexts. See Radio Corporation of America v. Radio Engineering Laboratories, Inc., 293 U. S. 1, 7-8 (invalidity of patent); Ward & Gow v. Krinsky, 259 U. S. 503, 522 (constitutional invalidity of state statute); Moore v. Crawford, 130 U. S. 122, 134 (invalidity of title); cf. Fidelity Mutual Life Assn. v. Mettler, 185 U. S. 308, 317.
See Idaho Dept. of Employment v. Smith, 434 U. S. 100, 103-105 (Stevens, J., dissenting in part).