
119 S.W.3d 4 (2002)
James H. McCLAIN, and Wife Syble McClain and Children of James H. McClain, Mac McClain and Jacqueline Birdman, Appellants,
v.
The UNIVERSITY OF TEXAS HEALTH CENTER AT TYLER, Appellee.
No. 12-01-00363-CV.
Court of Appeals of Texas, Tyler.
October 9, 2002.
Rehearing Overruled November 8, 2002.
*5 Ron Adkison, Wellborn, Houston, Adkison, Mann, Sadler & Hill, LLC, Henderson, for appellants.
Cherie Batsell, for appellee.
Panel consisted of GOHMERT, JR., C.J., WORTHEN, J., and GRIFFITH, J.
JIM WORTHEN, Justice.
Appellants, James H. McClain, Syble McClain, Mac McClain, and Jacqueline Birdman, appeal from the trial court's order dismissing their cause of action against the University of Texas Health Center at Tyler (the "Hospital") for want of jurisdiction. In three issues, they assert the trial court erred in concluding that the Hospital is immune from suit. We affirm.

PROCEDURAL BACKGROUND
This is a medical negligence suit arising out of the treatment and care of James H. McClain while he was a patient at the Hospital. On June 27, 1990, Mr. McClain underwent heart surgery. He was discharged from the Hospital on July 10, 1990. Shortly thereafter, Mr. McClain contracted a surgical incision infection. He was readmitted to the hospital on July 16, 1990 and treated for the infection until his discharge on October 4, 1990. In 1992, Appellants sued the Hospital and others alleging negligence in medical treatment. As the Hospital is a governmental entity, it invoked the doctrine of sovereign immunity.
The Hospital filed a plea to the jurisdiction and motion to dismiss and sever asserting that Mr. McClain's petition failed to show the Hospital had, pursuant to the Texas Tort Claims Act, waived its governmental immunity from suit. In 2001, the trial court granted the plea to the jurisdiction, dismissed the claims against the Hospital, and severed the claims against it from the claims against the remaining defendants.

GROUNDS FOR WAIVER OF IMMUNITY
In their first issue, Appellants assert that the trial court erred in granting the Hospital's plea to the jurisdiction and dismissing the claims against the Hospital because their petition properly invoked the trial court's jurisdiction by asserting claims meeting the Tort Claims Act's requirements for showing waiver of governmental immunity. They contend the petition described claims against the Hospital based on the use or misuse of tangible personal property. They assert that an item among the instruments and equipment used during the course of Mr. McClain's surgery was infected and caused his infection by introducing the infection-causing *6 bacteria into Mr. McClain. Appellants argue that the trial court inappropriately dismissed their suit on jurisdictional grounds based on the Hospital's argument that its negligence did not cause Mr. McClain's infection. Such an argument, they assert, improperly requires them to prove the causation element of their claim, when all they are required to do is allege a causal connection between the use of the property and the injury.
In their second issue, Appellants assert the trial court improperly dismissed their claims based on the condition of tangible personal property because tangible personal property used to operate on Mr. McClain was contaminated with bacteria. They assert that the bacterial contamination of the instruments and equipment used in the operating room rendered these instruments and equipment inadequate and this inadequacy was a condition that injured Mr. McClain.
In their third issue, Appellants contend the trial court erred in dismissing their claims against the Hospital based on the use of and condition of real property, specifically, the operating room. They argue that the operating room was contaminated by infectious bacteria, that use of that room was the proximate cause of Mr. McClain's infection and, alternatively, that the contamination constitutes a condition on the property which caused harm.

APPLICABLE LAW
Sovereign immunity is an affirmative defense that must be pleaded and proved. Davis v. City of San Antonio, 752 S.W.2d 518, 520 (Tex.1988). Immunity from suit bars an action against the State unless the State expressly consents to the suit. Texas Dep't of Trans. v. Jones, 8 S.W.3d 636, 638 (Tex.1999). Since as early as 1847, the law in Texas has been that, absent the State's consent to suit, a trial court lacks subject matter jurisdiction. Id. The absence of subject matter jurisdiction may be raised by a plea to the jurisdiction, as well as by other procedural vehicles, such as a motion for summary judgment. Bland Indep. Sch. Dist. v. Blue, 34 S.W.3d 547, 554 (Tex.2000). Because subject matter jurisdiction presents a question of law, we review the trial court's decision to grant a plea to the jurisdiction de novo. Mayhew v. Town of Sunnyvale, 964 S.W.2d 922, 928 (Tex. 1998).
In reviewing a plea to the jurisdiction, we review the pleadings and any evidence relevant to the jurisdictional issue. Texas Dep't of Crim. Justice v. Miller, 51 S.W.3d 583, 587 (Tex.2001). Further, the trial court must consider evidence when necessary to resolve the jurisdictional issues raised. Blue, 34 S.W.3d at 555. Because a court must not act without determining that it has subject matter jurisdiction to do so, it should hear evidence as necessary to determine the issue before proceeding with the case. Id. at 554. Whether a determination of subject matter jurisdiction can be made in a preliminary hearing or should await a fuller development of the merits of the case must be left largely to the trial court's sound exercise of discretion. Id. The party suing the governmental entity must establish the State's consent, which may be alleged either by reference to a statute or to express legislative permission. Jones, 8 S.W.3d at 638. In considering the jurisdictional allegations contained in a petition, they are to be construed liberally in the plaintiff's favor. Texas Ass'n of Bus. v. Texas Air Control Bd., 852 S.W.2d 440, 446 (Tex.1993).
The Tort Claims Act (the "Act") provides a limited waiver of sovereign immunity when personal injury is "caused by a condition or use of tangible personal or *7 real property if the governmental unit would, were it a private person, be liable to the claimant according to Texas law." Tex. Civ. Prac. & Rem.Code Ann. § 101.021(2) (Vernon 1997). To sue the State for a tort, the pleadings must state a claim under the Act. Jones, 8 S.W.3d at 639. Mere reference to the Act is not enough. Miller, 51 S.W.3d at 587. We must look to the terms of the Act, considered together with the particular facts of the case, to determine if immunity has been waived. Id. "Use" means "to put or bring into action or service; to employ for or apply to a given purpose." Id. at 588. Claims involving the failure to use, or the non-use of property, are not within the waiver of sovereign immunity. Id. at 587-88. Further, information does not constitute tangible personal property and the State has not waived governmental immunity for negligence involving the use, misuse, or nonuse of information. University of Tex. Med. Branch v. York, 871 S.W.2d 175, 179 (Tex.1994).
Under the Act, for immunity to be waived, personal injury must be proximately caused by the condition or use of tangible property. Dallas County Mental Health and Mental Retardation v. Bossley, 968 S.W.2d 339, 343 (Tex.1998). Property does not cause injury if it does no more than furnish the condition that makes the injury possible. Id. The requirement of causation is more than mere involvement; otherwise the waiver of immunity would be virtually unlimited. Id. To establish that immunity has been waived, a plaintiff must allege a cause of action in which the tangible property is the instrumentality of the harm. Id. at 342; Baston v. City of Port Isabel, 49 S.W.3d 425, 429 n. 4 (Tex. App.-Corpus Christi 2001, pet. denied).
We must recognize that the Legislature intended the waiver in the Act to be limited. Bossley, 968 S.W.2d at 341. "Arguments for applications of the Act that would essentially result in its waiver becoming absolute must therefore be rejected as contrary to the Act's fundamental purpose." Id. at 342. Further, while the trial court may now consider evidence on the issue of jurisdiction, the trial court is not to assess the merits of the underlying cause of action when determining the jurisdictional issue. See Blue, 34 S.W.3d at 554.

THE PETITION
In paragraph VII of Appellants' petition, they assert that their suit is brought against the Hospital pursuant to the Texas Tort Claims Act, and allege that Mr. McClain's personal injuries were caused by a condition or use of tangible personal or real property. They further allege that, if the Hospital were a private party, it would be liable to Appellants according to Texas law. In paragraph X, Appellants allege that Mr. McClain's injury was a direct and/or proximate result of the negligence of the agents, representatives and/or employees of the Hospital. They further assert that, at all relevant times, the Hospital owed Appellants a duty to use the skill and care which was ordinarily used by a reasonably prudent person and/or reasonably prudent health care provider in similar cases and under similar circumstances. In paragraph XI, they allege the Hospital, by and through acts and omissions, failed to treat Mr. McClain in a manner consistent with the accepted standard of care for patients, thereby breaching duties owed to him.
Paragraph XIV is entitled "Plaintiffs' Claims Against Defendant, the University of Texas Health Center at Tyler, Based on Use of Tangible Personal Property or Real Property." Paragraph XV is entitled "Plaintiffs' Claims Against Defendant, The *8 University of Texas Health Center at Tyler, Based on Misuse of Tangible Personal Property or Real Property." Under these paragraphs, Appellants allege that the acts and omissions of the Hospital were a proximate cause of Mr. McClain's injuries 1) in the use and misuse of real property, being the operating room and surgery area for cardiac patients; 2) in the use and misuse of twenty-one named items of tangible personal property in the operating room and surgery area, as well as all attachments and related equipment; 3) in the use and misuse of twenty-one named items of tangible personal property referred to in the Operative Record; 4) in the use and misuse of items of tangible personal property referred to and described in records attached as exhibits to the petition; and 5) in the use and misuse of antibiotics, gloves, masks, gauze, dressings and dressing solutions to treat the infection.

PLEA TO THE JURISDICTION
The Hospital filed a plea to the jurisdiction and motion to dismiss and sever based on entitlement to sovereign immunity under the Texas Tort Claims Act. It asserted that Appellants failed to state a claim based on a condition or use of property. Rather, it argued, Appellants simply asserted that Mr. McClain contracted an infection subsequent to surgery and Appellants point to an exhaustive list of operating room materials as potential culprits. Asserting that Mr. McClain was not physically injured by the equipment provided by the Hospital in terms of its operative use, the Hospital argued that failure to use, failure to act, or non-use claims do not satisfy the use-of-property requirement. The Hospital further asserted that Appellants failed to establish that any negligence on the part of any of its employees was the proximate cause of Mr. McClain's injuries. The Hospital disagreed with Appellants' assertion that use of one or more of the named surgical instruments is the proximate cause of Mr. McClain's infection because property does not cause injury if it does no more than furnish the condition that makes the injury possible.
The Hospital contended that Appellants have not established what, if any, piece of equipment caused Mr. McClain's infection. Further, the Hospital argued that Appellants' allegation that allowing nurse Ellen Thompson, who eventually cultured positive for the same bacterium as Mr. McClain, to work in the operating room does not amount to a use of property under the Act. Finally, regarding Appellants' allegation that the Hospital was negligent in not following infection control policies, the Hospital asserted that information is not tangible personal or real property and, therefore, sovereign immunity is not waived by using, misusing, or not using information. The plea was supported by affidavits of three defendant nurses and portions of the deposition of Appellants' expert.
The Hospital presented the affidavits of Ellen Thompson, a staff nurse in the surgery department, Pat Gee, operating room charge nurse, and Odelia Peters, a nurse, Director of the Operating Room, and member of the Infection Control Committee. Ms. Peters stated that Hospital policies for infection control were in compliance with community standards. Explaining that there were no visible indicia of infection on Ms. Thompson's person, both Ms. Peters and Ms. Gee denied being aware that Ms. Thompson had a skin infection. Ms. Gee stated that Hospital policies and procedures were in compliance with established guidelines. Ms. Thompson explained that, at the time of Mr. McClain's surgery, she had no evidence of or any reason to believe she had any of the infection-causing bacteria on her body. Prior to surgery, she scrubbed completely from hands to elbows *9 with iodine and/or betadine and an antibiotic cleanser. She wore scrubs at all times, covered her hair, wore a mask, and covered her shoes. She was only briefly in the surgical suite, never invaded the sterile field during surgery, and had no physical contact with Mr. McClain.
The Hospital also presented portions of the deposition of Appellants' expert, Dr. Zaki A. Sheikh. Dr. Sheikh testified that infections can be incurred by patients despite the surgeons and all operating room personnel following the standard of care in sterile technique. He also explained that a patient can have bacteria on his body that could cause him to have an infection. Additionally, he testified that it is possible to get an infection either at the time of surgery or at a later date. When asked if diptheroid, a bacterium, can be found commonly on skin without an infection, he answered, "Probably." He agreed that if Ms. Thompson tested positive for diptheroid three weeks after Mr. McClain's surgery, it is possible that she developed it sometime within that three week period.

APPELLANTS' RESPONSE
Along with their response to the plea to the jurisdiction, Appellants filed Dr. Sheikh's affidavit. Dr. Sheikh explained that Ms. Thompson was tested and found to have on her hands a bacterium which was the same type as that involved in Mr. McClain's infection. He averred that the conduct of the individual defendants fell below the standards of practice and duty in the community for control and prevention of infection in the operating room. He stated that the defendants committed negligent acts and omissions in their care of Mr. McClain, and caused injury to him by failing to have and enforce a policy regarding the control and prevention of infection and by failing to train and instruct personnel how to perform their duties without infecting patients.

DISCUSSION
The Hospital's immunity is waived if Appellants' pleadings and the evidence before the trial court show that Mr. McClain's injury, the post-surgery infection, was caused by a condition of, or the Hospital's use or misuse of, personal or real property. In paragraph VII of Appellants' pleadings, they invoked the Act by setting out the requirements of section 101.021(2). But such a reference is not sufficient to state a claim under the Act. Miller, 51 S.W.3d at 586. Paragraphs XIV and XV again make bare assertions that the Hospital's use and misuse of personal and real property caused Mr. McClain's injuries. The petition names the operating room and surgical area, lists forty-eight items, and refers to countless others, alleging that the room and all of these items were used and that use of the room and all of these items was a proximate cause of Mr. McClain's injuries. The allegations in the petition, however, do not include a description of any defective condition, any explanation of how the room or any of the items were used, by whom, in what way any specific item was negligently used or misused, or in what way any one of the items caused the infection. Because of its generality, the petition does not establish that immunity has been waived under the "condition" or "use" of personal or real property provisions of the Act. We now consider the jurisdictional evidence before the trial court to determine if immunity was waived.
In his affidavit, Dr. Sheikh provides insight into Appellants' theory of causation explaining that Ms. Thompson suffered from the same infection as Mr. McClain. He contends the defendants were negligent and caused Mr. McClain's injury by *10 failing to have and enforce a policy for controlling and preventing infection and by failing to train and instruct personnel in proper infection control methods. The affidavits of the three nurses attempt to rebut Appellants' theory that Ms. Thompson had a skin infection at the time of Mr. McClain's surgery and that she infected him. At the same time, they attempt to show that they followed proper procedures for infection control. The Hospital also attempts to call Appellants' theory into doubt by Dr. Sheikh's deposition testimony that infections can happen even when the standard of care is followed and that the patient can infect himself.
Although Dr. Sheikh's affidavit presents Appellants' theory of causation, it falls short of explaining what piece of tangible personal or real property Ms. Thompson, or anyone on behalf of the Hospital, used or misused, or how she did so. The mere allegation that a Hospital employee used or misused some item on Appellants' list is insufficient. Without proof that a specific act or item of property contributed to the injury, there can be no proximate cause. See Ager v. Wichita Gen. Hosp., 977 S.W.2d 658, 662 (Tex.App.-Fort Worth 1998, no pet.). Even assuming Ms. Thompson was infected at the time of Mr. McClain's surgery, which is not shown by the record, she is not herself tangible personal or real property. Appellants have not submitted evidence that any specific piece of tangible property was actually in a contaminated condition which was the probable cause of Mr. McClain's injuries.
Appellants argue that the Hospital's interpretation of applicable law improperly requires them to prove the causation element of their cause of action. However, when discussing the Act's requirement to show causation in order to show waiver, the cases discuss evidence of such causation. See Tex. Civ. Prac. & Rem.Code Ann. § 101.021(2); Bossley, 968 S.W.2d at 343. Appellants assert that a plaintiff is merely required to allege that a causal connection exists between the use of the property and the injury. However, the law requires more when the jurisdiction of the trial court is challenged. If, as Appellants assert, a plaintiff were merely required to allege that a causal connection exists between the use of the property and the injury, the result would be contrary to legislative intent. Such an interpretation of the law would result in automatic waiver of sovereign immunity, making waiver the norm. This is contrary to the Act's fundamental purpose of limiting waiver. Id. at 342.
To the extent Appellants contend the Hospital failed to use proper sterilization techniques, that contention falls into the category of non-use of property which is not within the waiver of sovereign immunity. Miller, 51 S.W.3d at 587. Appellants' argument that the Hospital was negligent in failing to implement and enforce a policy for controlling and preventing infection involves misuse of information. Such claims do not involve tangible personal or real property and do not invoke waiver of sovereign immunity. York, 871 S.W.2d at 179. Appellants' argument that the hospital was negligent in failing to properly train personnel does not invoke waiver as such failures in conduct do not involve the use of tangible personal or real property. See Texas Dep't of Pub. Safety v. Petta, 44 S.W.3d 575, 581 (Tex.2001). Further, to the extent Appellants allege that some unspecified item on their list was unsterile or contaminated and led to Mr. McClain's infection, we disagree that "condition" is such as is contemplated by the Act. This argument in actuality is that the item merely furnished the condition that made the injury possible and is insufficient to meet the causation requirement for immunity *11 to be waived. Bossley, 968 S.W.2d at 343.

CONCLUSION
Based on the record before us, exactly how Mr. McClain became infected, or through what condition, or the use or misuse of what item of personal or real property caused the infection, is all conjecture. Thus, Appellants ask the court to assume causation. Appellants have not shown what tangible property was the "instrumentality of the harm." See id. at 342. In sum, Appellants' arguments are not supported by the factual allegations in the pleadings or extrinsic evidence in the record. We overrule issues one, two, and three.
We affirm the trial court's order of dismissal.
LOUIS GOHMERT, JR., C.J., concurring.
LOUIS GOHMERT, JR., Chief Justice, concurring.
I concur in the result of the majority opinion because it is consistent with the latest, highest authority. However, it bears noting that opinions such as that expressed in Brannon v. Pacific Employers Ins. Co., 148 Tex. 289, 224 S.W.2d 466, 469 (1949) and others including Firemen's Insurance Co. v. Board of Regents, 909 S.W.2d 540 (Tex.App.-Austin 1995, writ denied) were well conceived and logically written when stating that in a plea to the jurisdiction, the trial court must ordinarily base its decision solely on the pleadings. In Bland Indep. Sch. Dist. v. Blue, 34 S.W.3d 547, 554 (Tex.2000), the supreme court disapproved the language in the Firemen's Insurance Co. case to the extent it, and its cited precedent, limited a trial court's consideration to the pleadings in deciding a plea to the jurisdiction. Citing a damage issue, the Bland decision attempted to distinguish its well reasoned opinion in the Brannon case from that of the logical follow up in Firemen's, a case in which the highest court felt comfortable enough to deny the 1995 application for writ.
Consideration of evidence in pleas to the jurisdiction, as is apparently now authorized in many situations, confuses the law by merging pleas to the jurisdiction into motions for summary judgment. As appellate courts, we should endeavor to make the law consistent and logical. Bleeding one legal concept into another can slowly bleed the life out of the law. At a time when lawyers and laymen alike are yearning for clarity in law, graying areas that once were acutely clear is not helpful.
Requiring a litigant to, in effect, prove himself worthy of being in court with evidence on a plea to the jurisdiction confounds the notion of open courts. Though it would seem more appropriately addressed as a no-evidence summary judgment matter, evidentiary justification for being in court is now apparently required in a scenario as is before us. In the present case, a summary judgment motion and ruling thereon would certainly have been understandable after nine years of litigation without a trial.
In another vein, when pleadings lack clarity or specificity, special exceptions are available. Special exceptions might have been anticipated in this case years ago as some of the allegations of Appellants are obscure, general, or insufficient on their face. Others do not involve an exception to sovereign immunity. Some may. However, this case involves the ruling on a plea to the jurisdiction. Were this a ruling on a summary judgment, there would have been no concurring opinion, but rather one unanimous opinion in this case.
*12 Nonetheless, the learned trial court followed, as required of it as well as our court, the ruling in Bland Indep. Sch. Dist. v. Blue, 34 S.W.3d 547, 554 (Tex.2000). Until such time as the law may be modified again by the court above, we must affirm.
