opinion: Aminta FLORES, et al., Plaintiffs-Appel-lees Cross-Appellants, v. EDINBURG CONSOLIDATED INDEPENDENT SCHOOL DISTRICT, et al., Defendants-Appellants Cross-Appellees.
  No. 83-2195.
  United States Court of Appeals, Fifth Circuit.
  Sept. 17, 1984.
  Rehearing and Rehearing En Banc Denied Nov. 1, 1984.
  See also, 554 F.Supp. 974.
  Alfonso Ibanez, L. Aron Pena, Edinburg, Tex., Roy S. Dale, Brownsville, Tex., for defendants-appellants cross-appellees.
  Mitchell J. Green, Conde Thompson Cox, Asst. Attys. Gen., Austin, Tex., amicus curiae, for State of Tex.
  Douglas M. Becker, Ray Goldstein, Austin, Tex., for Edinburg Consol. Indep. School Dist.
  Larry Watts, Laura Oren, Houston, Tex., for plaintiffs-appellees cross-appellants.
  Before GARZA, GARWOOD, and HIGGINBOTHAM, Circuit Judges. .
  HIGGINBOTHAM, Circuit Judge:
  The Edinburg Consolidated Independent School District appeals from a judgment entered against it in this § 1983 action brought by the administratrix of the estate of David Flores, a junior high school student who suffered an injury to his hand in a classroom accident and later committed suicide. A jury found that the school district’s negligence had caused an infringement of Flores’s constitutionally-protected right not to have his bodily integrity impaired by unsafe school conditions, and awarded damages of $550,000. A suit in state court identical to the federal suit, except that its legal theory was state tort rather than constitutional tort, resulted in a summary judgment for. defendants on grounds of sovereign immunity. Because we conclude that under Texas law the present suit is barred by the doctrine of res judicata, we reverse the judgment and order that judgment be entered for the defendants.
  I
  In January 1977, when he was fourteen years old, Flores was using a power circular saw in his woodworking class and suffered a severe cut to his right hand; at the time of the injury, the saw’s safety guard had been removed and the teacher was in an area of the classroom from which he could not observe or supervise students using the power tools. Although surgery was successful in saving Flores’s hand, the hand was left permanently deformed — a condition that evidently preyed on Flores’s mind. The Flores family blames this condition for Flores’s eventual suicide in October 1981.
  in January 1979 Flores sued the school district and his woodshop teacher in the Texas state court, arguing that their negligence had been the cause of his injury, Defendants were granted summary judgment before trial on the ground of sovereign immunity. Tex.Civ.Stat.Ann. art. 6252-19a (waiver of immunity in Texas Tort Claims Act does not apply to school districts). No appeal from this judgment was ever perfected.
  In September 1980 Flores filed the present suit in the district court, alleging that the school board’s custom or policy of disregarding safety concerns had led to Flores’s injury; a right of recovery was asserted under 42 U.S.C. § 1983. Flores’s woodshop teacher was also named as a defendant, but he was granted summary judgment by reason of qualified governmental immunity. The school board’s motion for summary judgment, which raised inter alia the issue of res judicata, was denied. The case proceeded to trial and resulted in a judgment for the plaintiffs. The school district appeals.
  jj
  The Texas law of res judicata is traceable at least back to Foster v. Wells, 4 Tex. 101 (1849), and has not changed significantly since that time. The most frequently cited early statement of the rule is found in Freeman v. McAninch, 87 Tex. 132, 27 S.W. 97, 100 (1894), where the Texas Supreme Court declared that “[a] party cannot relitigate matters which he might have interposed, but failed to do, in a prior action between the same parties or their privies, in reference to the same subject matter” Thus> a judgment “is not only final as matter actually determined, but as every other matter which the parties uaight litigate in the cause, and which they might have had decided. Id.
  On its face, this broad statement of the rule suggests that every claim that might be permissibly joined in one suit must be so joined or will be forfeited. The Texas Supreme Court, however, soon explained that it understood the rule “to mean only that a11 matters which properly belong to a caAlse °f action asserted in the pending su^> such as will sustain or defeat, in whole or in part, that cause of action, must he produced or be barred by the judgment, an(^ n0^ ^at all of the different causes of ac^on a Party maY have ^ respecting the same property must be joined, because ^hey may be, in one proceeding. Moore v. Snowball, 98 Tex. 16, 81 S.W. 5, 8 (1904). ^he court quoted approvingly from Freeman on Judgments 249: The general expression, ... that a judgment is conclusive eveiT matter which the parties might have htigated in the action, is misleading. What is really meant by this expression is that a judgment is conclusive upon the tendered by the plaintiff’s corn- ^ am '
  More recently, these early statements of the doctrine of res judicata were reaffirmed in Abbott Laboratories v. Gravis, 470 S.W.2d 639, 642 (Tex.1971):
  [A]n existing final judgment rendered upon the merits by a court of competent jurisdiction upon a matter within its jurisdiction is conclusive of the rights of the parties in all other actions on the points at issue and adjudicated in the first suit. Further, the rule of res judicata in Texas bars litigation of all issues connected with a cause of action or defense which, with the use of diligence, might have been tried in a former action as well as those which were actually tried.
  Thus the scope of the res judicata bar is dependent on a determination of which issues are “connected with a cause of action or defense” in the first suit.
  The Texas Supreme Court has never explicitly stated what becomes of an issue that is actually raised in the first action but not decided there because a judgment on the merits is entered on some other ground. However, if res judicata barred the relitigation only of those issues actually decided in the first action, it would be indistinguishable from collateral estoppel with respect to the issues raised in the pleadings; only with respect to issues that should have been raised in the pleadings but were not raised would res judicata pose a greater bar than collateral estoppel. See Gilbert v. Fireside Enterprises, Inc., 611 S.W.2d 869, 871 & n. 4 (Tex.Civ.App.1980). Furthermore, if the pleading of a different legal theory would have induced the court to decide a particular issue in the first action, the issue is plainly one “which, with the use of diligence, might have been tried in [the] former action.” Diligence is, in brief, a key determinant of the applicability of the res judicata bar to any particular case.
  Some uncertainty about this rule has arisen since the Texas Supreme Court’s decision in Griffin v. Holiday Inns of America, 496 S.W.2d 535 (Tex.1973). In Griffin, a contractor sued his employer alleging that the two parties had had a contract, that the contractor had performed under their contract, and that he had not been paid. Judgment was entered for the employer. The contractor then sued on a theory of quantum meruit, but the Court of Civil Appeals affirmed its dismissal on the basis of res judicata. Reversing, the Texas Supreme Court noted that, although the quantum meruit claim could have been joined with the contract claim, the two actions were factually independent; the contractor could recover in quantum meruit while conceding that there was no actual contract between the parties or that, if there was an actual contract, he had not fully performed. The ease was thus analogous to Moore v. Snowball, where the plaintiff in the second suit conceded without reservation all of the factual issues placed in dispute by his prior action. The only things common to the first and second suits in Moore and Griffin were the property and the transaction, respectively, underlying the suits; the legal theories and factual bases were, in both cases, entirely distinct.
  In Gravis, decided by the Texas Supreme Court two years before Griffin, the court found that a plaintiff’s suit against a drug manufacturer upon a strict liability theory was barred by an earlier adverse judgment in a suit upon a negligence theory identical as to parties and overlapping in material ways in their facts. The court rejected the argument that the judgment in the negligence action should be no bar because negligence is not an issue in a products liability suit. Because “[b]oth suits involve[d] a tort action resulting from the furnishing of the same drug for the same operation on the same person,” 470 S.W. at 642, the court held that the two claims were obliged to be brought in a single action. In short, a change in legal theory was not enough to justify separate actions.
  The present plaintiffs are in an even weaker position than the Gravis plaintiffs because the shift in legal theory from their state suit to their federal suit does not free them from reliance on the factual allegations made in their state complaint. Though the legal bases for the two actions are distinct — § 1983 in place of Texas tort law — the crucial factual issue raised by plaintiffs’ complaints in both actions is the alleged negligence of officials of the school district. Flores, however, relies upon the following declaration by the Griffin court:
  Freeman [v. McAninch] has been consistently cited for the proposition that all grounds of recovery or defense relating to the cause of action asserted in the pending suit must be urged or will be barred by the judgment. Ogletree v. Crates, Tex.Sup., 363 S.W.2d 431; Moore v. Snowball, 98 Tex. 16, 81 S.W. 5. We have not said or held that a judgment in a suit on one claim or cause of action is necessarily conclusive of all claims and causes of action against the same party, or relating to the same property, or arising out of the same transaction____ ... As a general rule a judgment on the merits in a suit on one cause of action is not conclusive of a subsequent suit on a different cause of action except as to issues of fact actually litigated and determined in the first suit. See Moore v. Snowball____
  496 S.W.2d at 537-38 (additional citations omitted).
  The question raised but not answered by Griffin — as by Gravis — is what constitutes a “different cause of action” for res judicata purposes. Flores argues in effect that a “different cause of action” is a suit grounded in a different legal theory, the factual underpinnings of which need not be different from the factual underpinnings of the prior suit so long as those factual issues were not actually litigated and decided in the prior suit. By this test, res judicata would not bar the present suit because § 1983 is a legal basis for recovery distinct from Texas tort law, and the principal factual issue in the two suits — the school board’s alleged negligence — was not determined in the earlier state court action. As we have noted above, however, this view leaves res judicata a dead letter in the sense that it would be no broader a rule than collateral estoppel with respect to issues raised in the pleadings.
  In this Erie -like inquiry, we do not independently examine the policies behind the choices made by Texas courts. Rather, we attempt faithfully to apply Texas law. Consistent with this surrogate role, our primary reason for rejecting Flores’s reading of Griffin is its heavy reliance upon Moore v. Snowball, where the court declared definitively that “a judgment is conclusive upon the issues tendered by the plaintiffs complaint,” 81 S.W. at 8 (emphasis added). We conclude therefore that “a different cause of action” is one that proceeds not only on a sufficiently different legal theory but also on a different factual footing as not to require the trial of facts material to the former suit; that is, an action that can be maintained even if all the disputed factual issues raised in the plaintiff’s original complaint are conceded in the defendant’s favor. Dobbs v. Navarro, 506 S.W.2d 671, 673 (Tex.Civ.App.1974). Flores, as we have previously noted, cannot meet this standard, for to concede the factual issues previously raised would be to admit that the school officials were not negligent.
  This result is not so harsh as it may first appear. The doctrine of res judicata, like a statute of limitations, penalizes lapses in diligence, thereby assuring potential defendants that their exposure to liability is not wholly open-ended. Flores has offered no excuse for the failure to join the § 1983 action with the state tort claim. All of the information relating to the school district’s alleged negligence was surely as available to the plaintiffs when they filed their state lawsuit as when they filed the federal suit. Beyond this, there is no suggestion that any fact necessary to the filing of the § 1983 action first came to plaintiffs’ attention after the state action had been decided.
  Flores, however, would have us overlook this issue of diligence and permit successive suits to be prosecuted so long as the policies underlying the doctrine of res judi-cata are not offended. We are, of course, obliged to apply this rule if it is the approach that would be followed in the Texas state courts, see note 3, supra, and this framework does appear to have been adopted by the Texas Courts of Civil Appeals in Dallas and Houston.
  In Gilbert v. Fireside Enterprises, Inc., 611 S.W.2d 869 (Tex.Civ.App.1980), the Dallas court reviewed several possible ways that “cause of action” might be defined for res judicata purposes, and ultimately concluded that the Texas courts have employed a functional case-by-case approach designed to effectuate the policy considerations underlying the doctrine of res judica-ta: “promotion of judicial economy, prevention of vexatious litigation, prevention of double recovery, and promotion of the stability of decisions.” Id. at 877. If consideration of a second suit would pose no threat to any of these interests, the court concluded, the successive action may be entertained. This formulation was later followed by the Houston court in Cohen v. Cohen, 663 S.W.2d 617, 620 (Tex.Civ.App. 1984). The district court below accepted the Gilbert formulation as an accurate statement of the Texas law of res judicata, and held consequently that the present action was not barred because there was 1) no waste of judicial resources in view of the summary disposition of Flores’s state court suit, 2) no risk of double recovery, 3) no evidence of purposeful vexatiousness in the failure to join the two claims in a single suit, and 4) no threat to the stability of the state court judgment.
  We cannot agree that Gilbert accurately states the Texas law. Gilbert purports to make a subjective policy-based determination in each case, but it will in practice prove nearly as mechanical as, and likely more arbitrary than the constructs it purports to reject. There is no great waste of judicial resources in any case decided summarily; there is no risk of double recovery in any case where the plaintiff lost his first suit; purposeful vexatiousness will seldom appear, and Gilbert would raise no bar where the splintering of the actions is not done purposefully; and finally, the stability of a judgment is imperiled only if an issue has been decided in the prior suit, in which case the collateral estoppel doctrine already bars relitigation.
  In brief, the Gilbert rule draws several intersecting lines based on concepts of judicial economy and stability rather than a single line based on the diligence of the plaintiff. This approach is not without merit, and might yet be adopted by the Texas Supreme Court at some future time. We conclude, however, that the present law of res judicata, as enunciated by the Texas Supreme Court for well over a century, is not so constricted. As Griffin states, issues of fact actually litigated and determined in one suit are barred in all later suits, whether or not the later suit arises from the same cause of action; only when the subsequent suit is on a different cause of action will those issues which have not been actually litigated and determined not be barred. 496 S.W.2d at 538. If the subsequent suit is not on a different cause of action, even issues not actually litigated in the prior suit will be barred.
  Whether two lawsuits constitute “different causes of action” must be an objective determination. A different cause of action is not merely a different theory of recovery; it should differ in “the theories of recovery, the operative facts, and the measure of recovery,” Dobbs v. Navarro, 506 S.W.2d 671, 673 (Tex.Civ.App.1974) (emphasis added). A contrary rule, süch as that adopted by the Gilbert court, cannot be harmonized with the holding in Moore that res judicata operates upon all the issues tendered in the plaintiff’s complaint. As Moore is plainly still 'good law, having been cited in several of the recent Texas Supreme Court decisions, we conclude that Gilbert is not an authoritative statement of the Texas law of res judicata.
  Plaintiffs, by acting diligently, could have brought all of their claims in the original suit in the Texas courts. Consequently, a successive suit grounded in the same operative facts cannot now be maintained. Plaintiffs have done no more in their § 1983 action than to advance a new theory of recovery; however, “[t]he assertion of a theory of recovery different from that of the first suit is not enough to state a new cause of action under Texas law.” Wilson v. Wilson, 532 F.Supp. 152, 155 (M.D.La.1980), aff'd, 667 F.2d 497 (5th Cir.), cert, denied, 458 U.S. 1107, 102 S.Ct. 3485, 73 L.Ed.2d 1368 (1982). As the present suit was barred by res judicata, the judgment for the plaintiffs must be reversed and judgment entered for the defendants.
  REVERSED.
  . After David Flores’s suicide, his mother was certified as administratrix of his estate and was substituted as plaintiff in that capacity. Flores’s mother and father are also named as plaintiffs in their individual capacities.
  . In light of our disposition of this case, we need not consider most of the grounds of appeal urged by the school board, including the question of whether plaintiffs have identified a constitutionally-protected interest that was impaired by defendants’ conduct. As to these issues we intimate no views.
  . In a § 1983 action we accord the prior judgment the same preclusive effect that it would have in the state courts. Migra v. Warren City School Dist. Bd. of Educ., — U.S.-, 104 S.Ct. 892, 79 L.Ed.2d 56 (1984). A summary judgm^nt on pounds of sovereign immunity is a Judgment on the merits for purposes of res judicata. Herring v. Texas Dept, of Corrections 500 S.W.2d 718, 720 (Tex.Civ.App.1973), aff'd, 513 S.W.2d 6 (Tex.1974).
  . As an incidental matter, we disagree with the school district’s argument that the above-quoted portion of Griffin was dicta overruled by the Texas Supreme Court in Texas Water Rights Com'n. v. Crow Iron Works, 582 S.W.2d 768 (Tex.1979). Crow, if anything, reaffirms Griffin —a natural result, because Griffin is consistent with the longstanding res judicata jurisprudence in Texas. Specifically, the Crow court defined the doctrine of res judicata as stating "that a cause of action once finally determined ... cannot afterwards be litigated by new proceedings.’’ Id. at 771 (emphasis added). Moreover, this circuit has already indicated that it does not believe Griffin to change the Texas law of res judicata; in Brachett v. Universal Life Insurance Co., 519 F.2d 1072, 1073 (5th Cir.1975), — a post-Griffin decision — we restated the traditional Texas formulation of res judicata (almost exactly as it was later restated by the Texas Supreme Court in Crow ) without citing Griffin, but citing Abbott Laboratories v. Gravis.
  . It is unquestioned that a § 1983 claim can be advanced in a state court suit, as state courts exercise concurrent jurisdiction with federal courts over such claims. Kutzik v. Young, 730 F.2d 149, 152 (4th Cir. 1984). As sovereign immunity is no defense to a claim grounded in § 1983, Flores could have obtained full and fair consideration of his complaint if he had joined his § 1983 claim to his state tort claim; consequently, there is no basis here for an exception to the traditional bar of res judicata. See Allen v. McCurry, 449 U.S. 90, 101 S.Ct. 411, 418, 66 L.Ed.2d 308 (1980).