opinion: UNITED STATES PAROLE COMMISSION et al. v. GERAGHTY
  No. 78-572.
  Argued October 2, 1979
  Decided March 19, 1980
  Blackmon, J., delivered the opinion of the Court, in which Brennan, White, Marshall, and Stevens, JJ., joined. Powell, J., filed a dissenting opinion, in which Burger, C. J., and Stewart and Rehnquist, JJ., joined, post, p. 409.
  Kent L. Jones argued the cause pro hac vice for petitioners. With him on the briefs were Solicitor General McCree, Assistant Attorney General Heymann, Deputy Solicitor General Easterbrook, Jerome M. Feit, and Elliott Schulder.
  Kenneth N. Flaxman argued the cause for respondent. With him on the brief was Thomas R. Meites.
  Robert J. Hobbs filed a brief for the National Client Council, Inc., et al. as amici curiae urging affirmance.
  Mb. Justice Blackmun
  delivered the opinion of the Court.
  This case raises the question whether a trial court’s denial of a motion for certification of a class may be reviewed on appeal after the named plaintiff’s personal claim has become “moot.” The United States Court of Appeals for the Third Circuit held that a named plaintiff, respondent here, who brought a class action challenging the validity of the United States Parole Commission’s Parole Release Guidelines, could continue his appeal of a ruling denying class certification even though he had been released from prison while the appeal was pending. We granted certiorari, 440 U. S. 945 (1979), to consider this issue of substantial significance, under Art. Ill of the Constitution, to class-action litigation, and to resolve the conflict in approach among the Courts of Appeals.
  I
  In 1973, the United States Parole Board adopted explicit Parole Release Guidelines for adult prisoners. These guidelines establish a "customary range” of confinement for various classes of offenders. The guidelines utilize a matrix, which combines a “parole prognosis” score (based on the prisoner’s age at first conviction, employment background, and other personal factors) and an “offense severity” rating, to yield the “customary” time to be served in prison.
  Subsequently, in 1976, Congress enacted the Parole Commission and Reorganization Act (PCRA), Pub. L. 94-233, 90 Stat. 219, 18 U. S. C. §§ 4201-4218. This Act provided the first legislative authorization for paroie release guidelines. It required the newly created Parolé Commission to “promulgate rules and regulations establishing guidelines for the powefr] ... to grant or deny an application or recommendation to parole any eligible prisoner.” § 4203. Before releás-ing a prisoner on parole, the Commission must find, “upon consideration of the nature and circumstances of the offense and the history and characteristics of the prisoner,” that release “would not depreciate the seriousness of his offense or promote disrespect for the law” and that it “would not jeopardize the public welfare.” § 4206 (a).
  Respondent John M. Geraghty was convicted in the United States District Court for the Northern District of Illinois of conspiracy to commit extortion, in violation of 18 U. S. C. § 1951, and of making false material declarations to a grand jury, in violation of 18 U. S. C. § 1623 (1976 ed. and Supp. II). On January 25, 1974, two months after initial promulgation of the release guidelines, respondent was sentenced to concurrent prison terms of four, years on the conspiracy count and one year on the false declarations count. The United States Court of Appeals for the Seventh Circuit affirmed respondent’s convictions. United States v. Braasch, 505 F. 2d 139 (1974), cert. denied sub nom. Geraghty v. United States, 421 U. S. 910 (1975).
  Geraghty later, pursuant to a motion under Federal Rule of Criminal Procedure 35, obtained from the District Court a reduction of his sentence to 30 months. The court granted the motion because, in the court’s view, application of the guidelines would frustrate the sentencing judge’s intent with respect to the length of time Geraghty would serve in prison. United States v. Braasch, No. 72 CR 979 (ND Ill., Oct. 9, 1975), appeal dism’d and mandamus denied, 542 F. 2d 442 (CA7 1976).
  Geraghty then, applied for release on parole. His first application was denied in January 1976 with the following explanation:
  “Your offense behavior has been rated as very high severity. You have a salient factor score of 11. You have been in custody for a total of 4 months. Guidelines established by the Board for adult cases which consider the above factors indicate a range of 26-36 months to be served before release for cases with good institutional program performance and adjustment. After review of all relevant factors and information presented, it is found that a decision at this consideration outside the guidelines does not appear warranted.” App. 5.
  If the customary release date applicable to respondent under the guidelines were adhered to, he would not be paroled before serving his entire sentence minus good-time credits. Geraghty applied for parole again in June 1976; that application was denied for the same reasons. He then instituted this civil suit as a class action in the United States District Court for the District of Columbia, challenging the guidelines as inconsistent with the PCRA and the Constitution, and questioning the procedures by which the guidelines were applied to his case.
  Respondent sought certification of a class of “all federal prisoners who are or who will become eligible for release on parole.’’ Id., at 17. Without ruling on Geraghty’s motion, the court transferred the case to the Middle District of Pennsylvania, where respondent was incarcerated. Geraghty continued to press his motion for class certification, but the court postponed ruling on the motion until it was prepared to render a decision on cross-motions for summary judgment.
  The District Court subsequently denied Geraghty’s request for class certification and granted summary judgment for petitioners on all the claims Geraghty asserted. 429 F. Supp. 737 (1977). The court regarded respondent’s action as a petition for a writ of habeas corpus, to which Federal Rule of Civil Procedure 23 applied only by analogy. It denied class certification as “neither necessary nor appropriate.” 429 F. Supp., at 740. A class action was “necessary” only to avoid mootness. The court found such a consideration not comprehended by Rule 23. It found class certification inappropriate because Geraghty raised certain individual issues and, inasmuch as some prisoners might be benefited by the guidelines, because his claims were not typical of the entire proposed class. 429 F. Supp., at 740-741. On the merits, the court ruled that the guidelines are consistent with the PCRA and do not offend the Ex Post Facto Clause, U. S. Const., Art. I, § 9, cl. 3. 429 F. Supp., at 741-744.
  Respondent, individually “and on behalf of a class,” appealed to the United States Court of Appeals for the Third Circuit. App. 29. Thereafter, another prisoner, Becher, who had been denied parole through application of the guidelines and who was represented by Geraghty’s counsel, moved to intervene. Becher sought intervention to ensure that the legal issue raised by Geraghty on behalf of the class “will not escape review in the appeal in this case.” Pet. to Intervene After Judgment 2. The District Court, concluding that the filing of Geraghty’s notice of appeal had divested it of jurisdiction, denied the petition to intervene. Becher then filed a timely notice of appeal from the denial of intervention. The two appeals were consolidated.
  On June 30, 1977, before any brief had been filed in the Court of Appeals, Geraghty was mandatorily released from prison; he had served 22 months of his sentence, and had earned good-time credits for the rest. Petitioners then moved to dismiss the appeals as moot. The appellate court reserved decision of the motion to dismiss until consideration of the merits.
  The Court of Appeals, concluding that the litigation was not moot, reversed the judgment of the District Court and remanded the case for further proceedings. 579 F. 2d 238 (CA3 1978). If a class had been certified by the District Court, mootness of respondent Geraghty’s personal claim would not have rendered the controversy moot. See, e. g., Sosna v. Iowa, 419 U. S. 393 (1975). The Court of Appeals reasoned that an erroneous denial of a class certification should not lead to the opposite result. 579 F. 2d, at 248-252. Rather, certification of a “certifiable” class, that erroneously had been denied, relates back to the original denial and thus preserves jurisdiction. Ibid.
  On the question whether certification erroneously had been denied, the Court of Appeals held that necessity is not a prerequisite under Rule 23. 579 F. 2d, at 252. The court expressed doubts about the District Court’s finding that class certification was “inappropriate.” While Geraghty raised some claims not applicable to the entire class of prisoners who are or will become eligible for parole, the District Court could have “certified] certain issues as subject to class adjudication, and . . . limite [d] overbroad classes by the use. of sub-classes.” Id., at 253. Failure “to consider these options constituted a failure properly to exercise discretion.” Ibid. “Indeed, this authority may be exercised sua sponte.” Ibid. The Court of Appeals also held that refusal to certify because of a potential conflict of interest between Geraghty and other members of the putative class was error. The subclass mechanism would have remedied this problem as well. Id., at 252-253. Thus, the Court of Appeals reversed the denial of class certification and remanded the case to the District Court for an initial evaluation of the proper subclasses. Id., at 254. The court also remanded the motion for intervention. Id., at 245, n. 21.
  In order to avoid “improvidently dissipating] judicial effort,” id., at 254, the Court of Appeals went on to consider whether the trial court had decided the merits of respondent’s case properly. The District Court’s entry of summary judgment was found to be error because “if Geraghty’s recapitulation of the function and genesis of the guidelines is supported by the evidence,” the guidelines “may well be” unauthorized or unconstitutional. Id., at 259, 268. Thus, the dispute on the merits also was remanded for further factual development.
  II
  Article III of the Constitution limits federal “judicial Power,” that is, federal-court jurisdiction, to “Cases” and “Controversies.” This .case-or-controversy limitation serves "two complementary” purposes. Flast v. Cohen, 392 U. S. 83, 95 (1968). It limits the business of federal courts to "questions presented in an adversary context and in a form historically viewed as capable of resolution through the judicial process,” and it defines the “role assigned to the judiciary in a tripartite allocation of power to assure that the federal courts will not intrude into areas committed to the other branches of government.” Ibid. Likewise, mootness has two aspects: “when the issues presented are no longer 'live’ or the parties lack a legally cognizable interest in the outcome.” Powell v. McCormack, 395 U. S. 486, 496 (1969).
  It is clear that the controversy over the validity of the Parole Release Guidelines is still a “live” one between petitioners and at least some members of the class respondent seeks to represent. This is demonstrated by the fact that prisoners currently affected by the guidelines have moved to be substituted, or to intervene, as “named” respondents in this Court. See n. 1, supra. We therefore are concerned here with the second aspect of mootness, that is, the parties’ interest in the litigation. The Court has referred to this concept as the “personal stake” requirement. E. g., Franks v. Bowman Transportation Co., 424 U. S. 747, 755 (1976); Baker v. Carr, 369 U. S. 186, 204 (1962).
  The personal-stake requirement relates to the first purpose of the case-or-controversy doctrine — limiting judicial power to disputes capable of judicial resolution. The Court in Flast v. Cohen, 392 U. S., at 100-101, stated:
  “The question whether a particular person is a proper party to maintain the action does not, by its own force, raise separation of powers problems related to improper judicial interference in areas committed to other branches of the Federal Government. . . . Thus, in terms of Article III limitations on federal court jurisdiction, the question of standing is related only to whether the dispute sought to be adjudicated will be presented in an adversary context and in a form historically viewed as capable of judicial resolution. It is for that reason that the emphasis in standing problems is on whether the party invoking federal court jurisdiction has ‘a personal stake in the outcome of the controversy/ Baker v. Carr, [369 U. S.], at 204, and whether the dispute touches upon ‘the legal relations of parties having adverse legal interests/ Aetna Life Insurance Co. v. Haworth, [300 U. S.], at 240-241.”
  See also Schlesinger v. Reservists to Stop the War, 418 U. S. 208, 216-218 (1974).
  The “personal stake” aspect of mootness doctrine also serves primarily the purpose of assuring that federal courts are presented with disputes they are capable of resolving. One commentator has defined mootness as “the doctrine of standing set in a time frame: The requisite personal interest that must exist at the commencement of the litigation (standing) must continue throughout its existence (mootness).” Monaghan, Constitutional Adjudication: The Who. and When, 82 Yale L. J. 1363, 1384 (1973).
  III
  On several occasions the Court has considered the application of the “personal stake” requirement in the class-action context. In Sosna v. Iowa, 419 U. S. 393 (1975), it held that mootness of the named plaintiff’s, individual claim after a class has been duly certified does not render the action moot. It reasoned that “even though appellees . . . might not again enforce the Iowa durational residency requirement against [the class representative], it is clear that they will enforce it against those persons in the class that appellant sought to represent and that the District Court certified.” Id., at 400. The Court stated specifically that an Art. Ill case or controversy “may exist . . . between a named defendant and a member of the class represented by the named plaintiff, even though the claim of the named plaintiff has become moot.” Id., at 402.
  Although one might argue that Sosna contains at least an implication that the critical factor for Art. Ill purposes is the timing of class certification, other cases, applying a “relation back” approach, clearly demonstrate that timing is not crucial. When the claim on the merits is “capable of repetition, yet evading review,” the named plaintiff may litigate the class certification issue despite loss of his personal stake in the outcome of the litigation. E. g., Gerstein v. Pugh, 420 U. S. 103, 110, n. 11 (1975). The “capable of repetition, yet evading review” doctrine, to be sure, was developed outside the class-action context. See Southern Pacific Terminal Co. v. ICC, 219 U. S. 498, 514-515 (1911). But it has been applied where the' named plaintiff does have a personal stake at the outset of the lawsuit, and where the claim may arise again with respect to that plaintiff; the litigation then may continue notwithstanding the named plaintiff's current lack of a personal stake. See, e. g., Weinstein v. Bradford, 423 U. S. 147, 149 (1975); Roe v. Wade, 410 U. S. 113, 123-125 (1973). Since the litigant faces some likelihood of becoming involved in the same controversy in the future, vigorous advocacy can be expected to continue.
  When, however, there is no chance that the named plaintiff’s expired claim will reoccur, mootness still can be avoided through certification of a class prior to expiration of the named plaintiff’s personal claim. E. g., Franks v. Bowman Transportation Co., 424 U. S., at 752-757. See Kremens v. Bart- ley, 431 U. S. 119, 129-130 (1977). Some claims are so inherently transitory that the trial court will not have even enough time to rule on a motion for class certification before the proposed representative’s individual interest expires. The Court considered this possibility in Gerstein v. Pugh, 420 U. S., at 110, n. 11. Gerstein was an action challenging pretrial detention conditions. The Court assumed that the named plaintiffs were no longer in custody awaiting trial at the time the trial court certified a class of pretrial detainees. There was no indication that the particular named plaintiffs might again be subject to pretrial detention. Nonetheless, the case was held not to be moot because:
  “The length of pretrial custody cannot be ascertained at the outset, and it may be ended at any time by release on recognizance, dismissal of the charges, or a guilty plea, as well as by acquittal or conviction after trial. It is by no means certain that any given individual, named as plaintiff, would be in pretrial custody long enough for a district judge to certify the class. Moreover, in this case the constant existence of a class of persons suffering the deprivation is certain. The attorney representing the named respondents is a public defender, and we can safely assume that he has other clients with a continuing live interest in the case.” Ibid.
  See also Sosna v. Iowa, 419 U. S., at 402, n. 11.
  In two different contexts the Court has stated that the proposed class representative who proceeds to a judgment on the merits may appeal denial of class certification. First, this assumption was “an important ingredient,” Deposit Guaranty Nat. Bank v. Roper, ante, at 338, in the rejection of interlocutory appeals, “as of right,” of class' certification denials. Coopers & Lybrand v. Livesay, 437 U. S. 463, 469, 470, n. 15 (1978). The Court reasoned that denial of class status will not necessarily be the “death knell” of a small-claimant action, since there still remains “the prospect of prevailing on the merits and reversing an order denying class certification.” Ibid.
  Second, in United Airlines, Inc. v. McDonald, 432 U. S. 385, 393-395 (1977), the Court held that a putative class member may intervene, for the purpose of appealing the denial of a class certification motion, after the named plaintiffs’ claims have been satisfied and judgment entered in their favor. Underlying that decision was the view that “refusal to certify was subject to appellate review after final judgment at the behest of the named plaintiffs.” Id., at 393. See also Coopers & Lybrand v. Livesay, 437 U. S., at 469. And today, the Court holds that named plaintiffs whose claims are satisfied through entry of judgment over their objections may appeal the denial of a class certification ruling. Deposit Guaranty Nat. Bank v. Roper, ante, p. 326.
  Gerstein, McDonald, and Roper are all examples of cases found not to be moot, despite the loss of a “personal stake” in the merits of the litigation by the proposed class representative. The interest of the named plaintiffs in Gerstein was precisely the same as that of Geraghty here. Similarly, after judgment had been entered in their favor, the named plaintiffs in McDonald had no continuing narrow personal stake in the outcome of the class claims. And in Roper the Court points out that an individual controversy is rendered moot, in the strict Art. Ill sense, by payment and satisfaction of a final judgment. Ante, at 333.
  These cases demonstrate the flexible character of the Art. III mootness doctrine. As has been noted in the past, Art. III justiciability is “not a legal concept with a fixed content or susceptible of scientific verification.” Poe v. Ullman, 367 U. S. 497, 508 (1961) (plurality opinion). “[T]he justi-ciability doctrine [is] one of uncertain and shifting contours.” Flast v. Cohen, 392 U. S., at 97.
  IV
  Perhaps somewhat anticipating today’s decision in Roper, petitioners argue that the situation presented is entirely different when mootness of the individual claim is caused by “expiration” of the claim, rather than by a judgment on the claim. They assert that a proposed class representative who individually prevails on the merits still has a “personal stake” in the outcome of the litigation, while the named plaintiff whose claim is truly moot does not. In the latter situation, where no class has been certified, there is no party before the court with a live claim, and it follows, it is said, that we have no jurisdiction to consider whether a class should have been certified. Brief for Petitioners 37-39.
  We do not find this distinction persuasive. As has been noted earlier, Geraghty’s “personal stake” in the outcome of the litigation is, in a practical sense, no different from that of the putative class representatives in Roper. Further, the opinion in Roper indicates that the approach to take in applying Art. III is issue by issue. “Nor does a confession of judgment by defendants on less than all the issues moot an entire case; other issues in the case may be appealable. We can assume that a district court’s final judgment fully satisfying named plaintiffs’ private substantive claims would preclude their appeal on that aspect of the final judgment; however, it does not follow that this circumstance would terminate the named plaintiffs’ right to take an appeal on the issue of class certification.” Ante, at 333. See also United Airlines, Inc. v. McDonald, 432 U. S., at 392; Powell v. McCormack, 395 U. S., at 497.
  Similarly, the fact that a named plaintiff’s substantive claims are mooted due to an occurrence other than a judgment on the merits does not mean that all the other issues in the case are mooted. A plaintiff who brings a class action presents two separate issues for judicial resolution. One is the claim on the merits; the other is the claim that he is entitled to represent a class. “The denial of class certification stands as an adjudication of one of the issues litigated,” Roper, ante, at 336. We think that in détermining whether the plaintiff may continue to press the class certification claim, after the claim on the merits “expires,” we must look to the nature of the “personal stake” in the class certification claim. Determining Art, Ill’s “uncertain and shifting contours,” see Flast v. Cohen, 392 U. S., at 97, with respect to nontraditional forms of litigation, such as the class action, requires reference to the purposes of the case-or-controversy requirement.
  Application of the personal-stake requirement to a procedural claim, such as the right to represent a class, is not automatic or readily resolved. A “legally cognizable interest,” as the Court described it in Powell v. McCormack, 395 U. S., at 496, in the traditional sense rarely ever exists with respect to the class certification claim. The justifications that led to the development of the class action include the protection of the defendant from inconsistent .obligations, the protection of the interests of absentees, the provision of a convenient and economical means for. disposing of similar lawsuits, and the facilitation of the spreading of litigation costs among numerous litigants with similar claims. See, e. g., Advisory Committee Notes on Fed. Rule Civ. Proc. 23, 28 U. S. C. App., pp. 427-429; Note, Developments in the Law, Class Actions, 89 Harv. L. Rev. 1318, 1321-1323, 1329-1330 (1976). Although the named representative receives certain benefits from the class nature of the action, some of which are regarded as desirable and others as less so, these benefits generally are byproducts of the class-action device. In order to achieve the primary benefits of class suits, the Federal Rules of Civil Procedure give the proposed class representative the right to have a class certified if the requirements of the Rules are met. This “right” is more analogous to the private attorney general concept than to the type of interest traditionally thought to satisfy the “personal stake” requirement. See Roper, ante, at 338.
  As noted above, the purpose of the “personal stake” requirement is to assure that the case is in a form capable , of judicial resolution. The imperatives of a dispute capable of judicial resolution are sharply presented issues in a concrete factual setting and self-interested parties vigorously advocating opposing positions. Franks v. Bowman Transportation Co., 424 U. S., at 753-756; Baker v. Carr, 369 U. S., at 204; Poe v. Ullman, 367 U. S., at 503 (plurality opinion). We conclude that these elements can exist with respect to the class certification issue notwithstanding the fact that the named plaintiff’s claim on the merits has expired. The question whether class certification is appropriate remains as a concrete, sharply presented issue. In Sosna v. Iowa it was recognized that a named plaintiff whose claim on the merits expires after class certification may still adequately represent the class. Implicit in that decision was the determination that vigorous advocacy can be assured through means other than the traditional requirement of a “personal stake in the outcome.” Respondent here continues vigorously to advocate his right to have a class certified.
  We therefore hold that an action brought on behalf of a class does not become moot upon expiration of the named plaintiff’s substantive claim, even though class certification has been denied. The proposed representative retains a “personal stake” in obtaining class certification sufficient to assure that Art. III values are not undermined. If the appeal results in reversal of the class certification denial, and a class subsequently is properly certified, the merits of the class claim then may be adjudicated pursuant to the holding in Sosna.
  Our holding is- limited to the appeal of the denial of the class certification motion. A named plaintiff whose claim expires may not continue to press the appeal on the merits until a class has been properly certified. See Roper, ante, at 336-337. If, on appeal, it is determined that class certification properly was denied, the claim on the merits must be dismissed as moot.
  Our conclusion that the controversy here is not moot does not automatically establish that the named plaintiff is entitled to continue litigating the. interests of the class. “[I]t does shift the focus of examination from the elements of justiciability to the ability of the named representative to ‘fairly and adequately protect the interests of the class.’ Rule 23 (a).” Sosna v. Iowa, 419 U. S., at 403. We hold only that a case or controversy still exists. The question of who is to represent the class is a separate issue.
  We need not decide here whether Geraghty is a proper representative for the purpose of representing the class on the merits.: No class as yet has been certified. Upon remand, the District Court can determine whether Geraghty may continue to press the class claims or whether another representative would be appropriate. We decide only that Geraghty was a proper representative for the purpose of appealing the ruling denying certification of the class that he initially defined. Thus, it was not improper for the Court of Appeals to consider whether the District Court should have granted class certification.
  y
  We turn now to the question whether the Court of Appeals’ decision on the District Court’s class certification ruling was proper. Petitioners assert that the Court of Appeals erred in requiring the District Court to consider the possibility of certifying subclasses sua sponte. Petitioners strenuously contend that placing the burden of identifying and constructing subclasses on the trial court creates unmanageable difficulties. Brief for Petitioners 43-51. We feel that the Court of Appeals’ decision here does not impose undue burdens on the district courts. Respondent had no real opportunity to request certification of subclasses after the class he proposed was rejected. The District Court denied class certification at the same time it rendered its adverse decision on the merits. Requesting subclass certification at that time would have been a futile act. The District Court was not about to invest effort in deciding the subclass question after it had ruled that no relief on the merits was available. The remand merely gives respondent the opportunity to perform his function in the adversary system. On remand, however, it is not the District Court that is to bear the burden of constructing subclasses. That burden is upon the respondent and it is he who is required to submit proposals to the court. The court has no sua sponte obligation so to act. With this modification, the Court of Appeals’ remand of the case for consideration of subclasses was a proper disposition.
  It would be inappropriate for this Court to reach the merits of this controversy in the present posture of the case. Our holding that the case is not moot extends only to the appeal of the class certification denial. If the District Court again denies class certification, and that decision is affirmed, the controversy on the merits will be moot. Furthermore, although the Court of Appeals commented upon the merits for the sole purpose of avoiding waste of judicial resources, it did not reach a final conclusion on the validity of the guidelines. Rather, it held only that summary judgment was improper and remanded for further factual development. Given the interlocutory posture of the case before us, we must defer decision on the merits of respondent’s case until after it is determined affirmatively that a class properly can be certified.
  The judgment of the Court of Appeals is vacated, and the case is remanded for further proceedings consistent with this opinion.
  It is so ordered.
  The grant of certiorari also included the question of the validity of the Parole Release Guidelines, an issue left open in United States v. Addonizio, 442 U. S. 178, 184 (1979). We have concluded, however, that it would be premature to reach the merits of that question at this time. See infra, at 408.
  While the petition for a writ of certiorari was pending, respondent Geraghty. filed a motion to substitute as respondents in this Court five prisoners, then incarcerated, who also were represented by Geraghty’s attorneys. In the alternative, the prisoners sought to intervene. We deferred our ruling on the motion to the hearing of the case on the merits. 440 U. S. 945 (1979). These prisoners, or most of them, now also have been released from incarceration. On September 25, 1979, a supplement to the motion to substitute or intervene was filed, proposing six new substitute respondents or intervenors; each of these is a presently incarcerated federal prisoner who, allegedly, has been adversely affected by the guidelines and who is represented by Geraghty’s counsel.
  Since we hold that respondent may continue to litigate the class certification issue, there is no need for us to. consider whether the motion should be granted in order to prevent the case from being moot. We conclude that the District Court initially should rule on the motion.
  See, e. g., Armour v. City of Anniston, 597 F. 2d 46, 48-19 (CA5 1979); Susman v. Lincoln American Cory., 587 F. 2d 866 (CA7 1978), cert. pending, No. 78-1169; Goodman v. Schlesinger, 584 F. 2d 1325, 1332-1333 (CA4 1978); Camper v. Calumet Petrochemicals, Inc., 584 F. 2d 70 (CA5 1978); Roper v. Consurve, Inc., 578 F. 2d 1106 (CA5 1978), aff’d sub nom. Deposit Guaranty Nat. Bank v. Roper, ante, p. 326; Satterwhite v. City of Greenville, 578 F. 2d 987 (CA5 1978) (en banc), cert. pending, No. 78-1008; Vun Cannon v. Breed, 565 F. 2d 1096 (CA9 1977); Winokur v. Bell Federal Savings & Loan Assn., 560 F. 2d 271 (CA7 1977), cert. denied, 435 U. S. 932 (1978); Lasky v. Quinlan, 558 F. 2d 1133 (CA2 1977); Kuahulu v. Employers Ins. of Wausau, 557 F. 2d 1334 (CA9 1977); Boyd v. Justices of Special Term, 546 F. 2d 526 (CA2 1976); Napier v. Gertrude, 542 F. 2d 825 (CA10 1976), cert. denied, 429 U. S. 1049 (1977).
  38 Fed. Reg. 31942-31945 (1973). The guidelines currently in force appear at 28 CFR § 2.20 (1979).
  The extortion count was based on respondent’s use of his position as a vice squad officer of the Chicago police force to “shake down” dispensers of alcoholic beverages; the false declarations concerned his involvement in this scheme.
  Apparently Becher, too, has.now been released from prison.
  The claim in Sosna also fit the traditional category of actions that are deemed not moot despite the litigant’s loss of personal stake, that is, those “capable of repetition, yet evading review.” See Southern Pacific Terminal Co. v. ICC, 219 U. S. 498, 515 (1911). In Franks v. Bowman Transportation Co., 424 U. S. 747, 753-755 (1976), however, the Court held that the class-action aspect of mootness doctrine does not depend on the class claim’s being so inherently transitory that it meets the “capable of repetition, yet evading review” standard.
  Three of the Court’s cases might be described as adopting a less flexible approach. In Indianapolis School Comm’rs v. Jacobs, 420 U. S. 128 (1975), and in Weinstein v. Bradford, 423 U. S. 147 (1975), dismissal of putative class suits, as moot, was ordered after the named plaintiffs’ claims became moot. And in Pasadena City Bd. of Education v. Spangler, 427 U. S. 424, 430 (1976), it was indicated that the action would have been moot, upon expiration of the named plaintiffs’ claims, had not the United States intervened as a party plaintiff. Each of these, however, was a case in which there was an attempt to appeal the merits without first having obtained proper certification of a class. In each case it was the defendant who petitioned this Court for review. As is observed subsequently in the text, appeal from denial of class classification is permitted in some circumstances where appeal on the merits is not. In the situation where the proposed class representative has lost a “personal stake,” the merits cannot be reached until a class properly is certified. Although the Court perhaps could have remanded Jacobs and Weinstein for reconsideration of the class certification issue, as the Court of Appeals did here, the parties in those cases did not suggest “relation back” of class certification. Thus we do not find this fine of cases dispositive of the question now before us.
  Were the class an indispensable party, the named plaintiff’s interests in certification would approach a “legally cognizable interest.”
  See, e. g., Landers, Of Legalized Blackmail and Legalized Theft: Consumer Class Actions and the Substance-Procedure Dilemma, 47 S. Cal. L. Rev. 842 (1974); Simon, Class Actions — Useful Tool or Engine of Destruction, 55 F. R. D. 375 (1972).
  We intimate no view as to whether a named plaintiff who settles the individual claim after denial of class certification may, consistent with Art. III, appeal from the adverse ruling on class certification. See United Airlines, Inc. v. McDonald, 432 U. S. 385, 393-394, and n. 14 (1977).
  Mr. Justice Powell, in his dissent, advocates a rigidly formalistic approach to Art. III, post, at 412, and suggests that our decision today is the Court’s first departure from the formalistic view. Post, at 414-419. We agree that the issue at hand is one of first impression and thus, in that narrow sense, is “unprecedented,” post, at 419. We do not believe, however, that the decision constitutes a redefinition of Art. III principles or a “significant departure],” post, at 409, from “carefully considered” precedents, post, at 418.
  The erosion of the strict, formalistic perception of Art. III was begun well before today’s decision. For example, the protestations of the dissent are strikingly reminiscent of Mr. Justice Harlan’s dissent in Flast v. Cohen, 392 U. S. 83, 116, in 1968. Mr. Justice Harlan hailed the taxpayer-standing rule pronounced in that case as a “new doctrine” resting “on premises that do not withstand analysis.” Id., at 117- He felt that the problems presented by taxpayer standing “involve nothing less than the proper functioning of the federal courts, and so run to the roots of our constitutional system.” Id., at 116. The taxpayers were thought to complain as “private attomeys-general,” and “[t]he interests they represent, and the rights they espouse, are bereft of any personal or proprietary coloration.” Id., at 119. Such taxpayer actions “are and must be ... . ‘public actions’ brought to vindicate public rights.” Id., at 120.
  Notwithstanding the taxpayers’ lack of a formalistic “personal stake,” even Mr. Justice Harlan felt that the case should be held nonjusticiable on purely prudential grounds. His interpretation of the cases led him' to conclude that “it is . . . clear that [plaintiffs in a public action] as such are not constitutionally excluded from the federal courts.” Ibid. (emphasis in original).
  Is it not somewhat ironic that Mr. Justice Powell, who now seeks to explain United Airlines, Inc. v. McDonald, supra, as a straightforward application of settled doctrine, post, at 416-417, expressed in his dissent in McDonald, 432 U. S., at 396, the view that the holding rested on a fundamental misconception about the mootness of an uncertified class action after settlement of the named plaintiffs’ claims? He stated:
  “Pervading the Court’s opinion is the assumption that the class action somehow continued after the District Court denied class status. But that assumption is supported neither by the text nor by the history of Rule 23. To the contrary, . . . the denial of class status converts the litigation to an ordinary nonclass action.” Id., at 399.
  The dissent went on to say:
  “[Petitioner] argues with great force that, as a result of the settlement of their individual claims, the named plaintiffs ‘could no longer appeal the denial of class’ status that had occurred years earlier. . . . Although this question has not been decided by this Court, the answer on principle is clear. The settlement of an individual claim typically moots any issues associated with it. . . . This case is sharply distinguishable from cases such as Sosna v. Iowa . . . and Franks v. Bowman Transp. Co.,. . . where we allowed named plaintiffs whose individual claims were moot to continue to represent their classes. In those cases, the District Courts previously had certified the classes, thus giving them ‘a legal status separate from the-interest[s] asserted by [the named plaintiffs].’ Sosna v. Iowa, supra, at 399. This case presents precisely the opposite situation: The prior denial of class status had extinguished any representative capacity.” Id., at 400 (footnote omitted).
  Thus, the assumption thought to be “[p]ervading the Court’s opinion” in McDonald, and so vigorously attacked by the dissent there, is now relegated to “gratuitous” “dictum,” post, at 416. Mr. Justice Powell, who finds the situation presented in the case at hand “fundamentally different” from that in Sosna and Franks', post, at 413, also found the facts of McDonald “sharply distinguishable” from those previous cases. 432 U. S., at 400.
  We do not recite these cases for the purpose of showing that our result is mandated by the precedents. We concede that the prior cases may be said to be somewhat confusing, and that some, perhaps, are irreconcilable with others. Our point is that the strict, formalistic view of Art. III jurisprudence, while perhaps the starting point of all inquiry, is riddled with exceptions. And, in creating each exception, the Court has looked to practicalities and prudential considerations. The resulting doctrine can be characterized, aptly, as “flexible”; it has been developed, not irresponsibly, but “with some care,” post, at 410, including the present case.
  The dissent is correct that once exceptions are made to the formalistic interpretation of Art. III, principled distinctions and bright lines become more difficult to draw. We do not attempt to predict how far down the road the Court eventually will go toward premising jurisdiction “upon the bare existence of a sharply presented issue in a concrete and vigorously argued case,” post, at 421. Each case must be decided on its own facts. We hasten to note, however, that this case does not even approach the extreme feared by the dissent. This respondent suffered actual, concrete injury as a result of the putatively illegal conduct, and this injury would satisfy the formalistic personal-stake requirement if damages were sought. See, e. g., Powell v. McCormack, 395 U. S., at 495-500. His injury continued up to and beyond the time the District Court denied class certification. We merely hold that when a District Court erroneously denies a procedural motion, which, if correctly decided, would have prevented the action from becoming moot, an appeal lies from the denial and the corrected ruling “relates back” to the date of the original denial.
  The judicial process will not become a vehicle for “concerned bystanders,” post, at 413, even if one in respondent’s position can conceivably be characterized as a bystander, because the issue on the merits will not be addressed until a class with an interest in the outcome has been certified. The. “relation back” principle, a traditional equitable doctrine applied to class certification claims in Gerstein v. Pugh, 420 U. S. 103 (1975), serves logically to distinguish this case from the one brought a day after the prisoner is released. See post, at 420-421, n. 15. If the named plaintiff has no personal stake in the outcome at the time class certification is denied, relation back of appellate reversal of that denial still would not prevent mootness of the action.
  See, e. g., Comment, A Search for Principles of Mootness in the Federal Courts: Part Two-Glass Actions, 54 Texas L. Rev. 1289, 1331-1332 (1976); Comment, Continuation and Representation of Class Actions Following Dismissal of the Class Representative, 1974 Duke L. J. 573, 602-608.