O'CONNOR, J., dissenting petition is one with a long history behind it, a history that did not begin with Townsend v. Sain. II The availability and scope of habeas corpus have changed over the writ's long history, but one thing has remained constant: Habeas corpus is not an appellate proceeding, but rather an original civil action in a federal court. See, e. g., Browder v. Director, Dept. of Corrections of Ill., 434 U. S. 257, 269 (1978). It was settled over a hundred years ago that "[t]he prosecution against [a criminal defendant] is a criminal prosecution, but the writ of habeas corpus. . . is not a proceeding in that prosecution. On the contrary, it is a new suit brought by him to enforce a civil right." Ex parte Tom Tong, 108 U.S. 556, 559-560 (1883). Any possible doubt about this point has been removed by the statutory procedure Congress has provided for the disposition of habeas corpus petitions, a procedure including such nonappellate functions as the allegation of facts, 28 U. S. C. § 2242, the taking of depositions and the propounding of interrogatories, § 2246, the introduction of documentary evidence, § 2247, and, of course, the determination of facts at evidentiary hearings, § 2254(d). To be sure, habeas corpus has its own peculiar set of hurdles a petitioner must clear before his claim is properly presented to the district court. The petitioner must, in general, exhaust available state remedies, § 2254(b), avoid procedural default, Coleman v. Thompson, 501 U. S. 722 (1991), not abuse the writ, McCleskey v. Zant, 499 U. S. 467 (1991), and not seek retroactive application of a new rule of law, Teague v. Lane, 489 U. S. 288 (1989). For much of our history, the hurdles were even higher. See, e. g., Ex parte Watkins, 3 Pet. 193, 203 (1830) (habeas corpus available only to challenge jurisdiction of trial court). But once they have been surmounted-once the claim is properly before the dis O'CONNOR, J., dissenting trict court-a habeas petitioner, like any civil litigant, has had a right to a hearing where one is necessary to prove the facts supporting his claim. See, e. g., Hawk v. Olson, 326 U. S. 271, 278–279 (1945); Holiday v. Johnston, 313 U. S. 342, 351-354 (1941); Walker v. Johnston, 312 U. S. 275, 285-287 (1941); Moore v. Dempsey, 261 U. S. 86, 92 (1923). Thus when we observed in Townsend v. Sain, 372 U. S., at 312, that "the opportunity for redress. . . presupposes the opportunity to be heard, to argue and present evidence," we were saying nothing new. We were merely restating what had long been our understanding of the method by which contested factual issues raised on habeas should be resolved. Habeas corpus has always differed from ordinary civil litigation, however, in one important respect: The doctrine of res judicata has never been thought to apply. See, e. g., Brown v. Allen, 344 U. S. 443, 458 (1953); Darr v. Burford, 339 U. S. 200, 214 (1950); Waley v. Johnston, 316 U. S. 101, 105 (1942); Salinger v. Loisel, 265 U. S. 224, 230 (1924). A state prisoner is not precluded from raising a federal claim on habeas that has already been rejected by the state courts. This is not to say that state court factfinding is entitled to no weight, or that every state prisoner has the opportunity to relitigate facts found against him by the state courts. Concerns of federalism and comity have pushed us from this extreme just as the importance of the writ has repelled us from the opposite extreme, represented by the strict application of res judicata. Instead, we have consistently occupied the middle ground. Even before Townsend, federal courts deferred to state court findings of fact where the federal district judge was satisfied that the state court had fairly considered the issues and the evidence and had reached a satisfactory result. See, e. g., Brown, supra, at 458, 465; Frank v. Mangum, 237 U. S. 309, 332-336 (1915). But where such was not the case, the federal court entertaining the habeas petition would examine the facts anew. See, e. g., Ex parte Hawk, 321 U. S. 114, 116, 118 (1944); Moore, supra, O'CONNOR, J., dissenting at 92. In Hawk, for example, we stated that a state prisoner would be entitled to a hearing, 321 U. S., at 116, "where resort to state court remedies has failed to afford a full and fair adjudication of the federal contentions raised... because in the particular case the remedy afforded by state law proves in practice unavailable or seriously inadequate." Id., at 118. In Brown, we explained that a hearing may be dispensed with only "[w]here the record of the application affords an adequate opportunity to weigh the sufficiency of the allegations and the evidence, and no unusual circumstances calling for a hearing are presented." 344 U. S., at 463. Townsend "did not launch the Court in any new directions," Weisselberg, Evidentiary Hearings in Federal Habeas Corpus Cases, 1990 B. Y. U. L. Rev. 131, 150, but it clarified how the district court should measure the adequacy of the state court proceeding. Townsend specified six circumstances in which one could not be confident that "the statecourt trier of fact has after a full hearing reliably found the relevant facts." 372 U. S., at 313. The Court held that a habeas petitioner is entitled to an evidentiary hearing on his factual allegations if "(1) the merits of the factual dispute were not resolved in the state hearing; (2) the state factual determination is not fairly supported by the record as a whole; (3) the fact-finding procedure employed by the state court was not adequate to afford a full and fair hearing; (4) there is a substantial allegation of newly discovered evidence; (5) the material facts were not adequately developed at the state-court hearing; or (6) for any reason it appears that the state trier of fact did not afford the habeas applicant a full and fair fact hearing." Ibid. That these principles marked no significant departure from our prior understanding of the writ is evident from the view expressed by the four dissenters, who had "no quarrel with the Court's statement of the basic governing principle which O'CONNOR, J., dissenting should determine whether a hearing is to be had in a federal habeas corpus proceeding," but disagreed only with the Court's attempt "to erect detailed hearing standards for the myriad situations presented by federal habeas corpus applications." Id., at 326-327 (Stewart, J., dissenting). Townsend thus did not alter the federal courts' practice of holding an evidentiary hearing unless the state court had fairly considered the relevant evidence. The Court expressed concern in Townsend that a petitioner might abuse the fifth circumstance described in the opinion, by deliberately withholding evidence from the state factfinder in the hope of finding a more receptive forum in a federal court. Id., at 317. To discourage this sort of disrespect for state proceedings, the Court held that such a petitioner would not be entitled to a hearing. Ibid. The Townsend opinion did not need to address this concern in much detail, because a similar issue was discussed at greater length in another case decided the same day, Fay v. Noia, 372 U. S. 391, 438-440 (1963). The Townsend opinion thus merely referred the reader to the discussion in Fay, where a similar exception was held to bar a state prisoner from habeas relief where the prisoner had intentionally committed a procedural default in state court. See Townsend, supra, at 317. Nearly 30 years later, the Court implies that Fay and Townsend must stand or fall together. Ante, at 5-8. But this is not so: The Townsend Court did not suggest that the issues in Townsend and Fay were identical, or that they were so similar that logic required an identical answer to each. Townsend did not purport to rely on Fay as authority; it merely referred to Fay's discussion as a shorthand device to avoid repeating similar analysis. Indeed, reliance on Fay as authority would have been unnecessary. Townsend was essentially an elaboration of our prior cases regarding the holding of hearings in federal habeas cases; Fay represented an overruling of our prior cases regarding procedural O'CONNOR, J., dissenting defaults. See Coleman v. Thompson, 501 U. S., at 744–747; Wainwright v. Sykes, 433 U. S. 72, 82 (1977). As the Court recognizes, ante, at 6, we have applied Townsend's analysis ever since. See, e. g., Vasquez v. Hillery, 474 U. S. 254, 258 (1986); Cuyler v. Sullivan, 446 U. S. 335, 341– 342 (1980); Jackson v. Virginia, 443 U. S. 307, 318 (1979); LaVallee v. Delle Rose, 410 U. S. 690, 693-694 (1973); Boyd v. Dutton, 405 U. S. 1, 3 (1972); Procunier v. Atchley, 400 U. S. 446, 451 (1971). But we have not, in my view, been unjustifiably clinging to a poorly reasoned precedent. While we properly abandoned Fay because it was inconsistent with prior cases that represented a better-reasoned balance of state and federal interests, the same cannot be said of Townsend. The Court today holds that even when the reliability of state factfinding is doubtful because crucial evidence was not presented to the state trier of fact, a habeas petitioner is ordinarily not entitled to an opportunity to prove the facts necessary to his claim. This holding, of course, directly overrules a portion of Townsend, but more than that, I think it departs significantly from the pre-Townsend law of habeas corpus. Even before Townsend, when a habeas petitioner's claim was properly before a federal court, and when the accurate resolution of that claim depended on proof of facts that had been resolved against the petitioner in an unreliable state proceeding, the petitioner was entitled to his day in federal court. As Justice Holmes wrote for the Court, in a case where the state courts had rejected-under somewhat suspicious circumstances-the petitioner's allegation that his trial had been dominated by an angry mob: "[I]t does not seem to us sufficient to allow a Judge of the United States to escape the duty of examining the facts for himself when if true as alleged they make the trial absolutely void." Moore, 261 U. S., at 92. The class of petitioners eligible to present claims on habeas may have been narrower in days gone by, and the class of claims one might present may have |