BARROW, Justice.
Relator, John M. Abell, seeks his release from the custody of the sheriff of Travis County by writ of habeas corpus. Abell has been remanded to the sheriff’s custody by the judge of the 126th District Court of Travis County until he has responded to an interrogatory posed to him by plaintiffs in a pending suit in which Abell is defendant. After Abell had been ordered to answer, he continued to refuse and was held in contempt and ordered to purge himself of contempt by answering the interrogatory. We granted Abell’s application for writ of habe-as corpus and set down the case for hearing. After hearing argument and consideration of the applicable authorities, we order the relator, Abell, discharged.
A discussion of the background facts is necessary. In August of 1978, two women sued Abell in separate suits alleging essentially the same complaint. They both allege that they were former patients of Dr. Abell,1 who was a psychologist duly licensed to practice under the laws of the State of Texas. Each alleges that during the course of their psychotherapy treatment, Dr. Abell gained their complete cooperation, and when they were psychologically powerless to resist, Abell had sexual intercourse with them. Each suit separately alleges several causes of action, including malpractice, assault and battery, fraud and deceit, and intentional infliction of emotional distress. Both claim actual and punitive damages. Abell has admitted sexual relations with the plaintiffs at his office but denies that the sexual intercourse was a part of his professional treatment. Although Abell admits charging for the therapy sessions in question, he denies charging for the particular time span during which the sexual intercourse occurred.
Abell refused to answer the following interrogatory in each plaintiff’s suit:
50. Please state whether you have kissed, touched, hugged, fondled or had any sexual contact of any type, including sexual intercourse, with any other current or former patient you have under[257]*257taken to treat? _ If so, please state:
a) The full name of each such patient;
b) The date of each sexual contact;
c) A complete description of each act of sexual contact; and
d) Whether each act of sexual contact occurred in your office or at some other location. If at some other location, give the full street address of said location.
The trial court initially ordered on October 30,1978, after a hearing, that Abell answer the question in both suits by November 3, 1978. The court’s order further provided for certain protections:
It is further ordered, adjudged and decreed that the answers to plaintiff’s interrogatory number 50 shall be provided to the court in a sealed envelope not to be opened except by further court order. Defendant’s answer to interrogatory number 50 will be restricted to patients of Dr. Abell subsequent to October 28, 1972. In answering interrogatory number 50, each name, if any, will further be identified by a number or letter for possible future use. Copies of all names, corresponding numbers or letters, and all other information contained in the sealed envelope shall also be provided to plaintiff’s counsel. Attorneys, as officers of the court, are ordered not to divulge these names to anyone not a party or attorney in this cause of action and to use the utmost care and discretion in contacting or approaching said individuals.2
On advice of counsel, Abell refused to answer, and on November 16, 1978, pursuant to a show cause hearing, the trial court rendered its judgment of contempt and order of commitment. Abell then applied to this Court for a writ of habeas corpus which was denied on January 1, 1979. He next applied for a writ of habeas corpus to the federal district court, which also denied relief. Abell appealed that decision to the U. S. Court of Appeals for the Fifth Circuit. While that appeal was pending, the Texas Legislature enacted Article 5561h, Tex.Rev. Civ.Stat.Ann., which provides for the confidentiality of mental health information of individuals. The act became effective on August 27, 1979.
On September 11, 1980, the Fifth Circuit court handed down its decision declining to decide the issue of Abell’s claim of a constitutional right of privacy until the Texas courts have resolved the issues of state law, particularly the applicability of the new state statute, Article 5561h. See Abell v. Frank, 625 F.2d 653 (5th Cir. 1980).
Abell then moved the Travis County District Court to reconsider its prior orders in light of the new statute. The trial court denied the motion and again committed Abell to the custody of the sheriff on December 1, 1980. Application for writ of habeas corpus was again requested of this Court. This writ was granted, the case set for hearing, and Abell released on bond pending our decision.
The threshold question involves the contention of plaintiffs that Abell’s collateral attack on the trial court’s order is impermissible under Ex Parte Lipscomb, 111 Tex. 490, 239 S.W. 1101 (1922). There Lipscomb was held in contempt for refusing to answer questions from the witness stand during trial on the grounds that the answers would violate the attorney-client privilege. This Court held that the existence of the privilege and the waiver of it were questions for the trial court to determine, not the witness, and habeas corpus cannot be used as a method of appealing those rulings or to correct errors in the admission or exclusion of evidence. The distinguishing facet of Lipscomb is that the question arose during trial. In the instant case, however, the problem arose during pre-trial discovery and is thus governed by the rule in Ex Parte Hanlon, 406 S.W.2d 204 (Tex.1966). We there held that a judgment of contempt was void because it was predicated on a pre-trial order that violated the permissible [258]*258limits of discovery allowed by the Texas Rules of Civil Procedure. The same result was reached in Ex Parte Shepperd, 513 S.W.2d 813 (Tex.1974), in which one of the relators was ordered discharged because the order of discovery was “unauthorized.”
Relator Abell has no effective remedy here by appeal from the trial court’s order. If he cannot collaterally attack the validity of the trial court’s judgment of contempt by writ of habeas corpus, he in effect has no remedy.
We next must determine whether the provisions of article 5561h, effective August 27, 1980, are to be applied to the order of the trial court, dated October 30, 1978, to answer the interrogatory and the subsequent order of contempt on November 16, 1978. Abell contends that the information sought is now privileged and he may not be required by the trial court to violate the law; therefore, he argues, he has been purged from contempt by the enactment of the statute.
The general rule is that there exists a presumption that an act is intended to operate prospectively and not retroactively. If there is any doubt, the intention will be resolved against retrospective operation of a statute. Gov’t Personnel Mutual Life Insurance Co. v. Wear, 151 Tex. 454, 251 S.W.2d 525 (1952). An act will not be applied retrospectively unless it appears by fair implication from the language used that it was the intent of the Legislature to make it applicable to both past and future transactions. In ascertaining legislative intent, the entire act must be examined, not just isolated provisions in the act. Merchants Fast Motor Lines v. Railroad Commission of Texas, 573 S.W.2d 502, 505 (Tex.1978); State v. Humble Oil & Refining Co., 141 Tex. 40, 169 S.W.2d 707 (1943); Gayle v. Lockhart, 167 S.W.2d 230 (Tex.Civ.App.—Waco 1942, writ ref’d).
Article 5561h3 provides in section 2(a) that communication between a patient/client and a professional is confidential and not to be disclosed except under certain instances set out in sec. 4. Also confidential are “[rjecords of the identity, diagnosis, evaluation or treatment of a patient/client which are created or maintained by a professional.” § 2(b). The privilege may be claimed by the patient/client or someone acting in his or her behalf, and may be claimed by the professional only on behalf of the patient/client. Several exceptions exist to the privilege, [259]*259but none are applicable here.4 A person aggrieved by a violation of the act is given a cause of action for civil damages.5 Nothing in the act indicates an intent that it be applied prospectively only. To the contrary, the act evidences a specific intention to protect communications and records arising prior to the effective date of the act. Section 2(d) states:
The prohibitions of this Act continue to apply to confidential communications or records concerning any patient/client irrespective of when the patient/client received services of a professional.
Thus, it is clear that the privilege extends to the matters declared confidential in the act regardless of when they occurred and are applicable to the interrogatory in question here.
Plaintiffs argue that because the trial court’s order to answer was prior in time to the effective date of the act, they acquired a vested right in obtaining the answer that the Legislature cannot take away or impair. They point to Article 1, sec. 16 of the Texas Constitution which provides:
No bill of attainder, ex post facto law, retroactive law, or any law impairing the obligation of contracts shall be made.
In practice, however, retroactive lawmaking has not been viewed as the gross abuse of [260]*260power once assumed. See Smith, Retroactive Laws and Vested Rights, 6 Texas L.Rev. 409, 414 (1928). This is so even though the Texas Constitution, by prohibiting the enactment of retroactive laws, affords greater protection to rights than the protection of the Constitution of the United States which limits its protections to rights founded upon contract. Mellinger v. City of Houston, 68 Tex. 37, 3 S.W. 249, 252 (1887).
It is well settled in this state that laws may not operate retroactively to deprive or impair vested substantive rights acquired under existing laws, or create new obligations, impose new duties, or adopt new disabilities in respect to transactions or considerations past. On the other hand, no litigant has a vested right in a statute or rule which affects remedy or is procedural in nature and which affects no vested substantive right. Changes in such statutes or rules are considered remedial in nature and have been held not to violate the provisions of Article 1, sec. 16 of the Constitution. Exxon Corp. v. Brecheen, 526 S.W.2d 519, 525 (Tex.1975); Texas Water Rights Commission v. Wright, 464 S.W.2d 642, 649 (Tex.1971); Deacon v. City of Euless, 405 S.W.2d 59, 62 (Tex.1966); McCain v. Yost, 155 Tex. 174, 284 S.W.2d 898, 900 (1955); Wilson v. Work, 122 Tex. 545, 62 S.W.2d 490 (1933); Phil Pierce Co. v. Watkins, 114 Tex. 153, 263 S.W. 905, 907 (1924); Mellinger v. City of Houston, supra; Brantley v. Phoenix Insur. Co., 536 S.W.2d 72, 74 (Tex.Civ.App.—Houston [1st Dist.] 1976, writ ref’d); Butler v. State Board of Education, 581 S.W.2d 751 (Tex.Civ.App.—Corpus Christi 1979, writ ref’d n. r. e.); City of Beaumont v. Bond, 546 S.W.2d 407, 410 (Tex.Civ.App.—Beaumont 1977, writ ref’d n. r. e.); Aetna Insurance Co. v. Richardelle, 528 S.W.2d 280, 284 (Tex.Civ,App.—Corpus Christi 1975, writ ref’d n. r. e.); Harrison v. Cox, 524 S.W.2d 387, 391 (Tex.Civ.App.—Fort Worth 1975, writ ref’d n. r. e.); Click v. Seale, 519 S.W.2d 913, 920 (Tex.Civ.App.—Austin 1975, writ ref’d n. r. e.); Petroleum Casualty Co. v. Canales, 499 S.W.2d 734, 738 (Tex.Civ.App.—Houston [1st Dist.] 1973, writ ref’d n. r. e.); Cooper v. Texas Board of Medical Examiners, 489 S.W.2d 129, 131 (Tex.Civ.App.—El Paso 1972, writ ref’d n. r. e.); Commercial Ins. Co. of Newark v. Lane, 480 S.W.2d 781, 783 (Tex.Civ.App.—Dallas 1972, writ ref’d n. r. e.); Regal Properties v. Donovitz, 479 S.W.2d 748, 751 (Tex.Civ.App.—Dallas 1972, writ ref’d n. r. e.); Bryant v. State, 457 S.W.2d 72, 78 (Tex.Civ.App.—Eastland 1970, writ ref’d n. r. e.); Brooks v. Texas Employers Insur. Ass’n, 358 S.W.2d 412 (Tex.Civ.App.—Houston 1962, writ ref’d n. r. e.); Bardwell v. Anderson, 325 S.W.2d 929, 939 (Tex.Civ.App.—Houston 1959, writ ref’d n. r. e.); see also 12 Tex.Jur.2d, Constitutional Law §§ 115-119 (1960).
An analysis of the cases cited demonstrates the consistency of the application of the rule by the courts. In the protection of vested rights, the courts have held that when the statute of limitations has run on a cause of action, a right to assert that as a defense vests in the defendant and cannot be taken away by legislative enactment. Wilson v. Work, supra; Brantley v. Phoenix Ins. Co., supra; Petroleum Casualty Co. v. Canales, supra. Likewise, the right of a married woman under disabilities of cover-ture to disavow a voidable contract was held to be vested at the time of the contract and could not be taken away from her by subsequent legislation. Click v. Seale, supra.
Conversely, retroactive laws have been upheld when no vested substantive right has been impaired but only the procedure or remedy has been changed. In such cases, the change will not affect or invalidate steps previously taken in pending litigation, but all subsequent proceedings will be governed by the new statute or rule as of its effective date, provided a reasonable time is afforded in which to act upon the new law. Exxon Corp. v. Brecheen, supra; Bardwell v. Anderson, supra. The following changes have been held to be remedial: change of jurisdiction of the court in which the litigation was pending, Regal Properties v. Donovitz, supra; authorization of additional remedy for collecting past-due child support, Harrison v. Cox, supra; repeal prior to [261]*261filing suit of statute granting statutory cause of action, Aetna Insur. Co. v. Richardelle, supra; change of statutory standard of review, Butler v. State Board of Education, supra; Cooper v. Texas Board of Medical Examiners, supra; change in municipal annexation law, Deacon v. City of Euless, supra; change in statute concerning admissible evidence, Exxon Corp. v. Brecheen, supra; amendment requiring suspension of law license during appeal of conviction, Bryant v. State, supra; change in city ordinance reducing salary of city employee, City of Beaumont v. Bond, supra; change in worker’s compensation statute for determining average weekly wage, Brooks v. Texas Employers Insur. Ass’n, supra; change in statute defining insurable interest, McCain v. Yost, supra. Since in none of these cases was there a savings clause to exempt pending suits, the litigation was governed by the new statute or rule as of its effective date. See Dickson v. Navarro County Levee Improv. Dist. No. 3, 135 Tex. 95, 139 S.W.2d 257, 259 (1940).
Plaintiffs argue, however, that they obtained a right to the answer to their interrogatory which “vested” when the trial court ordered Abell to answer the interrogatory and held him in contempt. Plaintiffs contend that the trial court’s actions fell into the category of past steps completed in pending litigation prior to the enactment of article 5561h, citing Goldman v. State, 277 S.W.2d 217 (Tex.Civ.App.—Amarillo 1954, writ ref’d). The holding of the court in Goldman, however, is that the Legislature did not intend for the statute under consideration to be applied retroactively, but only prospectively. See also Merchants Fast Motor Lines, Inc. v. Railroad Commission of Texas, 573 S.W.2d 502, 506 (Tex.1978). The Goldman court further held that no intent was manifested by the Legislature to deprive the trial court of its jurisdiction over the pending case despite a change in the statute. Even so, that court recognized that a procedural statute was involved.
We have been cited to no case in point by either side, nor have we found a case involving this situation. We must first determine if a vested right to the answer has been created by the trial court’s orders.
This Court in Texas Water Rights Commission v. Wright, supra, alluded with approval to the definition of vested rights set out by Justice Stayton in the 1887 case of Mellinger v. City of Houston, supra. There this Court stated:
A right has been well defined to be a well-founded claim, and a well-founded claim means nothing more nor less than a claim recognized or secured by law.
* * * * * *
[A] right, in a legal sense, exists, when, in consequence of the existence of given facts, the law declares that one person is entitled to enforce against another a given claim, or to resist the enforcement of a claim urged by another. Facts may exist out of which, in the course of time or under given circumstances, a right would become fixed or vested by operation of existing law, but until the state of facts which the law declares shall give a right comes into existence there cannot be in law a right; and for this reason it has been constantly held that, until the right becomes fixed or vested, it is lawful for the lawmaking power to declare that the given state of facts shall not fix it, and such laws have been constantly held not to be retroactive in the sense in which that term is used.
In DuPre v. DuPre, 271 S.W.2d 829, 832 (Tex.Civ.App.—Dallas 1954, no writ), the court quoted, with approval, the constitutional authority, Cooley, Const. Lim. p. 438 (6th ed.). Cooley states that a right cannot be considered a vested right unless it is something more than such a mere expectation as may be based upon an anticipated continuance of the present general laws; it must have become a title, legal or equitable to the present or future enjoyment of a demand or a legal exemption from the demand made by another.
This Court in City of Dallas v. Trammell, 129 Tex. 150, 101 S.W.2d 1009, 112 A.L.R. 997 (1937), considered the question of whether a retired policeman had a vested right to the full amount of his pension. We [262]*262there held that the Legislature had the power to reduce the pension since a policeman has no vested right to that which constitutes a mere expectancy based upon anticipated continuance of existing law. Even though the right of the policeman to receive a pension became vested when the contingency occurred that entitled him to . receive a pension, he had no vested right to a fixed sum of money.
In Exxon Corp. v. Brecheen, 519 S.W.2d 170, 183 (Tex.Civ.App.—Houston [1st Dist.] 1975), rev’d on other grounds, 526 S.W.2d 519, 525 (Tex.1975), the court considered a rule of evidence which was changed by the Legislature after the cause of action had arisen and suit filed but before the trial of the case. The court of civil appeals, in a holding expressly approved by the Supreme Court, found error in the trial court’s refusal to apply the amended rule at the time of trial. The court then said:
The statute in question, relating to admissibility of evidence, is procedural and remedial in nature, and all proceedings taken thereafter in pending litigation were governed thereby.
In the instant case, the legislative passage of article 5561h creates a privilege in certain activities growing out of professional medical and psychotherapeutic treatment. It thus relates to the admissibility of evidence and is procedural in nature. Neither the trial court’s order of October 1978 requiring that the interrogatory be answered nor the order of contempt of November 1978 created any vested right to receive an answer which was not subject to being divested by legislative act. The trial court itself could have changed its mind and rescinded the orders of October and November of 1978, an action it could not have taken had the rights under the order been vested rights. Plaintiffs’ right to an answer was at best a mere expectation based upon the anticipated continuance of existing law. When the authority granting the right has the power and discretion to take that right away, it cannot be said to be a vested right. City of Dallas v. Trammell, supra; City of Beaumont v. Bond, supra. Therefore, we hold that no constitutional prohibition exists to the application of article 5561h retroactively.
Moreover, there is some doubt about whether the statute has been applied retroactively. The remedial aspect of the statute relates to the answering of the interrogatory, not the asking of it, and no answer has yet been given. Even so, the statute was in full effect on December 1, 1980 when the trial court heard and overruled Abell’s motion to reconsider its prior orders. The privilege afforded by the statute was clearly applicable then.
Having held the provisions of the confidentiality statute, Article 5561h, are applicable to the trial court’s order, we must now address plaintiffs’ contention that the contacts inquired about are not privileged under the terms of the statute.
We have already discussed the general terms of the statute and quoted the relevant provisions in footnotes. It is not questioned that Abell falls within the definition of a “professional” under the Act. He was licensed by the State of Texas for the diagnosis, evaluation or treatment of a mental or emotional condition or disorder. See Article 5561h, section 1(a). Article 5561h makes confidential a patient’s/client’s identity, or any communication or records of a mental health care professional’s diagnosis, evaluation, or treatment of a patient/client. Art. 5561h, secs. 2(a) and 2(b).6
It must be emphasized that the statutory privilege is not for the benefit of the professional, but for the protection of the patient/client. The legislature recognized, however, that the patient’s/client’s privilege to keep his or her identity confidential would fail if the patient/client was required to personally assert the privilege. Accordingly, section 3(b) authorizes the profession[263]*263al to claim the privilege of confidentiality on behalf of the patient/client.
It is apparent that a primary purpose of this statute is to protect a patient/client against an invasion of privacy. The need for such purpose is demonstrated by the facts in this case. The general question posed by interrogatory number 50 seeks a simple “yes” or “no” answer to be a compound inquiry, i. e., whether Abell engaged in a variety of activity ranging from touching to having sexual intercourse with former or current patients. A “yes” answer thus would be required even if Abell merely touched other patients, but the inference drawn from a “yes” answer might be that Abell had sexual intercourse with other patients. This could prove highly embarrassing or perhaps even destructive of existing family relationships for women who were patients/clients of Abell at any time after 1972.
We conclude that the statute forbids disclosure of the identity of former patients/clients of Abell. Interrogatory number 50 specifically inquires as to the identity of patients/clients. Furthermore, it is seen from the allegations in plaintiffs’ petitions, that the inquiry is focused on the manner of treatment of former or current patients/clients by Abell. The so-called “protective order” issued by the trial court in connection with interrogatory number 50 affords no protection whatsoever to these patients/clients of Abell. While the original copy of Abell’s answers are required to be filed with the court in a sealed envelope, it is ordered that a copy of all names and “all other information contained in the sealed envelope” be furnished to plaintiffs’ counsel. These attorneys, as well as the plaintiffs, would then be at liberty to contact any of said persons and even to subpoena them for deposition or trial. This obviously would publicly identify such patients/clients of Abell and destroy their statutory privilege of confidentiality and right to privacy.
The trial court was therefore without authority to order Abell to disclose the identity and other information pertaining to his patients/clients and to hold him in contempt for refusing to violate the prohibitions of the privilege statute. In view of this holding, it is not necessary to consider if disclosure of the information requested of Abell violates his patients’ constitutional right of privacy.
It is ordered that Abell be discharged.
Dissenting opinion by SPEARS, J., in which CAMPBELL, RAY and WALLACE, JJ., join.