217 F.3d 951 (7th Cir. 2000)
Patrick J. Higgins,    Plaintiff-Appellant,v.State of Mississippi, et al.,    Defendants-Appellees.
No. 97-3521
In the  United States Court of Appeals  For the Seventh Circuit
Submitted June 8, 1999Decided June 30, 2000

Appeal from the United States District Court  for the Northern District of Illinois, Eastern Division.  No. 95 C 4464--Joan B. Gottschall, Judge.
Before Posner, Chief Judge, and Flaum and Rovner,  Circuit Judges.
Posner, Chief Judge.


1
This suit under 42 U.S.C.  sec. 1983 against Illinois and Mississippi, an  Illinois municipality, and various Illinois and  Mississippi officials charges a plot to kidnap  the plaintiff from an Illinois jail and bring him  to Mississippi to face criminal prosecution. The  district court gave judgment for the defendants.  The appeal raises only two issues that merit  discussion: whether a district court may dismiss  a suit on the basis of the Eleventh Amendment  even if the state has not invoked the amendment;  and when an admission made in a prior case can be  used in the current case. An alternative ground  not presented to the district court for  dismissing the states from the suit is that  states are not "persons" within the meaning of  section 1983 and so are not liable under that  statute. Arizonans for Official English v.  Arizona, 520 U.S. 43, 69 (1997); Will v. Michigan  Dept. of State Police, 491 U.S. 66 (1989). This  could well be thought a jurisdictional ground for  dismissal and hence one that we can and should  raise on our own though it was waived in the  district court, or alternatively a  nonjurisdictional ground that we can nevertheless  notice on our own because to do so would promote  federal-state comity; but this we need not  decide. The alternative ground, the Eleventh  Amendment, is secure, as we are about to see.


2
A state may, it is plain, waive its Eleventh  Amendment immunity from being sued in federal  court either legislatively, Atascadero State  Hospital v. Scanlon, 473 U.S. 234, 238 n. 1  (1985), or by an explicit waiver in the lawsuit  in which it is named as a defendant, Clark v.  Barnard, 108 U.S. 436, 447 (1883), provided that  the waiver is authorized by state law. Ford Motor  Co. v. Department of Treasury, 323 U.S. 459  (1945); Estate of Porter by Nelson v. Illinois,  36 F.3d 684, 690 (7th Cir. 1994). The question  this case presents is whether the state's failure  to invoke its Eleventh Amendment immunity, by  pleading or otherwise, in the suit in which it is  named as a defendant (assuming the state has not  legislated a waiver) operates as a forfeiture of  the immunity, in which event the district court  should not on its own initiative have dismissed  Illinois from the case, since Illinois never  bothered to respond to Higgins's complaint.


3
In Wisconsin Dept. of Corrections v. Schacht,  524 U.S. 381, 389 (1998), the Supreme Court  stated that "unless the State raises the matter  [i.e., its Eleventh Amendment immunity], a court  can ignore it." The implication (despite some  fudging in an earlier sentence--"the Eleventh  Amendment, however, does not automatically  destroy original jurisdiction," id. (emphasis  added)), contrary to earlier decisions such as  Wilson-Jones v. Caviness, 99 F.3d 203, 206 (6th  Cir. 1996), is that the Eleventh Amendment does  not deprive the federal court of its subject-  matter jurisdiction, Kennedy v. National Juvenile  Detention Ass'n, 187 F.3d 690, 696 (7th Cir.  1999); Parella v. Retirement Bd. of Rhode Island  Employees' Retirement System, 173 F.3d 46, 55  (1st Cir. 1999); see also Patsy v. Board of  Regents, 447 U.S. 496, 515 n. 19 (1982), since if  it did, the court could not ignore the presence  of an Eleventh Amendment immunity just because it  had not been argued. A more refined analysis  might distinguish between the "original" Eleventh  Amendment, which forbids the federal courts to  entertain diversity suits against states and thus  is clearly jurisdictional, from the later  interpretations that transformed the amendment  into a comprehensive charter of state sovereign  immunity, creating thus an affirmative defense  rather than a limitation on jurisdiction.


4
But that is an aside; the important point is  that the Court in Schacht (which was not a  diversity case, but a case in which the Eleventh  Amendment was the vehicle for a defense of  sovereign immunity, see 524 U.S. at 389) said  only that the federal court could ignore the  immunity in such a case, not that it must ignore  it. Nor would such a statement, implying that the  immunity conferred by the Eleventh Amendment is  no different from any other affirmative defense,  comport with the long line of cases holding that  federal courts may forgive the waiver of a  defense that is based on comity--the mutually  respectful deportment of sovereign entities,  including the quasi-sovereign entities that are  the states of the United States. See, e.g.,  Younger v. Harris, 401 U.S. 37, 40-41 (1971);  Eaglin v. Welborn, 57 F.3d 496, 499 (7th Cir.  1995) (en banc); Pittman v. Chicago Board of  Education, 64 F.3d 1098, 1101 (7th Cir. 1995). As  we put it in Hoover v. Wagner, 47 F.3d 845, 852  (7th Cir. 1995), "when matters of comity are  involved, the ordinary doctrines of waiver give  way." And in Pittman v. Chicago Bd. of Education,  64 F.3d 1098, 1101 (7th Cir. 1995), we said  specifically that "one of the exceptions to the  principle of waiver . . . that is recognized by  the Supreme Court and by this court concerns the  interest in maintaining harmonious relations  between the states and the federal government."  That interest is present when a state is hauled  into a federal court as a defendant, as happened  here.


5
We conclude, as have the other reported post-  Schacht decisions, that a federal court can raise  an Eleventh Amendment defense on its own  initiative, Parella v. Retirement Bd. of Rhode  Island Employees' Retirement System, supra, 173  F.3d at 54-55; United States ex rel. Long v. SCS  Business & Technical Institute, Inc., 173 F.3d  890, 892 n. 4 (D.C. Cir. 1999), and we retract  our unfortunate dictum on remand in Schacht that  "the [Supreme] Court ruled that a federal court  must not raise a potential Eleventh Amendment  issue sua sponte." Schacht v. Wisconsin Dept. of  Corrections, 175 F.3d 497, 501 (7th Cir. 1999).  That was not what the Supreme Court ruled. We  need not consider whether, as urged in Michelle  Lawner, Comment, "Why Federal Courts Should Be  Required to Consider State Sovereign Immunity Sua  Sponte," 66 University of Chicago Law Review 1261  (1999), courts should always notice an Eleventh  Amendment immunity on their own, and at the  earliest point in the litigation, in order to  prevent states from using the immunity  opportunistically.


6
The other issue we discuss arises from a written  statement that Higgins made in the criminal  proceedings against him in Mississippi, admitting  that he had waived extradition. The district  court relied on the statement in granting summary  judgment for the defendants, the statement being  inconsistent with Higgins's claim that he had not  waived extradition but instead had been  kidnapped. If the statement was a judicial  admission, which means, in effect, a waiver,  Solon v. Gary Community School Corp., 180 F.3d  844, 858 (7th Cir. 1999); Murrey v. United  States, 73 F.3d 1448, 1455 (7th Cir. 1996);  Keller v. United States, 58 F.3d 1194, 1198 n. 8  (7th Cir. 1995); Barnes v. Owens-Corning  Fiberglas Corp., 201 F.3d 815, 829 (6th Cir.  2000), here of any contention that Higgins did  not waive extradition, then it would be binding;  if it was merely an evidentiary admission, it  would not be--it would just be one more bit of  evidence to weigh against Higgins's denial, made  in his affidavit in the current suit, that he  ever waived extradition.


7
We needn't consider which type of admission it  was, judicial or evidentiary, because a judicial  admission binds only in the litigation in which  it is made. Kohler v. Leslie Hindman, Inc., 80  F.3d 1181, 1185 (7th Cir. 1996); Enquip, Inc. v.  Smith-McDonald Corp., 655 F.2d 115, 118 (7th Cir.  1981); Utility Sales Co. v. Certain-teed Products  Corp., 638 F.2d 1061, 1084 (7th Cir. 1981); Dugan  v. EMS Helicopters, Inc., 915 F.2d 1428, 1432  (10th Cir. 1990) (per curiam); United States v.  Raphelson, 802 F.2d 588, 592 (1st Cir. 1986).


8
In  any other suit, as the cases just cited make  clear, it operates merely as an evidentiary  admission; for remember that a judicial admission  is in the nature of a waiver. A waiver is a  deliberate relinquishment of a known right, and a  waiver made for purposes of one lawsuit needn't  have been intended to carry over to another.


9
How then was the district court able to rely  upon Higgins's waiver in the criminal proceedings  to show that he hadn't waived extradition, since  the court was confronted with contradictory  statements, creating an issue of credibility? The  answer is that there are exceptions to the  principle on which Higgins relies that  credibility cannot be determined in a summary  judgment proceeding. The applicable exception is  that a party cannot by affidavit retract damaging  admissions without a good explanation, e.g.,  Cleveland v. Policy Management Systems Corp., 526  U.S. 795, 806-07 (1999); United States v.  Stewart, 198 F.3d 984, 986 (7th Cir. 1999);  Seshadri v. Kasraian, 130 F.3d 798, 801-02 (7th  Cir. 1997), whether (as these cases make clear)  the admissions were made in a deposition, a  trial, another affidavit, or, as in this case, a  written statement not under oath (actually  statements, but we can ignore that detail).  Higgins neither questions the authenticity of the  statement that he made in the Mississippi  proceedings nor offers an explanation for the  contradiction, such as that he was coerced to  waive extradition. In these circumstances, the  district court was right to credit that statement  and disregard the later, contrary affidavit.


10
Affirmed.

