The Court of Appeals (in Case No. 24233) certified to this court the question quoted in the headnote above. It may be urged that under tbe act of 1931 (Ga. Laws 1931, p. 199) the right of review by certiorari may be invoked in such a case under see. 16 which provides: “In all respects in which the commission has power and authority under this act, proceedings
*76may be instituted, complaints - made and filed with it, process issued, hearings held, opinions, orders, and decisions made and filed; and any final order may be reviewed in any court of competent jurisdiction of this State under the conditions and subject to the limitations as now prescribed by law as relates to the Georgia Public Service Commission.” It must be observed that there is no provision in that language for an unconditional review, but that it is to be under the conditions and subject to the limitations as now prescribed by law as relates to the Georgia Public-Service Commission. By this nothing is added to any right that might already exist to review by certiorari a finding of the Public-Service Commission. The precise question has not heretofore been before this court, and for a survey of the decisions of other-jurisdictions many cases have been examined, but, to recall the words of Omar Khayyam, we came out by the same door through which we entered. “The adjudications respecting the cases wherein the function exercised is of such a character that a certiorari will or will not lie are very numerous and not always harmonious.” Throop on Public Officers, 765, § 802. The decisions of other jurisdictions do not afford much help, because they are governed by express statutory provisions as to review or appeal, and in a few cases the matter is determined by constitutional provision. We are to determine whether in this State, “subject to the limitations as now prescribed by law as relates to the Georgia Public Service Commission,” the writ will lie. It is provided in art. 6, sec. 4, par. 5, of the constitution that the superior courts “shall have power to correct errors in inferior judicatories by writ of certiorari, which shall only issue on the sanction of the judge,” etc. Code of 1933, § 2-3205. It is not apprehended that any one will contend that by its mere creation the Public-Service Commission became an inferior judicatory or court. But by statute the issuance of the writ became broadened, so that now “The writ of certiorari shall lie for the correction of errors committed by justices of the peace, corporation courts or councils, or any inferior judicatory, or any person exercising judicial powers, including the ordinary, except in cases touching the probate of wills, granting letters testamentary and of administration; also from the Supreme Court to the Court of Appeals as provided by section 2-3009.” Code of 1933, § 19-101. (Italics ours.) From the question propounded by the Court of *77Appeals we understand that the answer sought, as to the applicability of the writ, is as to a proceeding wherein the Public-Service Commission has revoked a certificate of public convenience and necessity because, in the opinion of the commission, a motor common carrier has abandoned passenger service along a certain highway. If, therefore, in the hearing, pursuant to which the certificate was revoked, the commission was “ exercising judicial powers,” it would seem that it would lie. But if the Public-Service Commission, in the circumstances suggested, was not exercising judicial powers, certiorari would not lie to review the finding of the commission. “The writ of certiorari lies to correct errors or restrain excesses of jurisdiction of inferior courts and officers acting judicially only. It will, therefore, not be issued to officers whose functions and duties are ministerial, executive, or legislative, and not judicial.” Meehem on Public Offices and Officers, p. 666, § 1001. “The fact that a public agent exercises judgment or discretion in the performance of his duty does not make his action or his functions judicial.” Id. 668, § 1005. See also Daniels v. Commissioners, 147 Ga. 295 (93 S. E. 887); City of Atlanta v. Blackman Health Resort, 153 Ga. 499 (113 S. E. 545); Bryant v. Board of Education Colquitt County, 156 Ga. 688 (119 S. E. 601). It is well settled that, in determining the nature of the action of public agents, the organic .law and the constitutional divisions of authority, legislative, executive, and judicial, must be kept in mind. Unquestionably the jurisdiction of the commission over the highways of the State is regulatory, and was delegated by the General Assembly in the lawful exercise of its powers. Stephens v. Central of Georgia Railway Co., 138 Ga. 625, 628 (75 S. E. 1041, 42 L. R. A. (N. S.) 541, Ann. Cas. 1913E, 609), in which Justice Hill furnishes an interesting discussion of such control. In McKinney v. Patton, 176 Ga. 719, 721 (169 S. E. 16), in quoting from the provisions of the motor common-carrier’s act as to what must be considered in determining whether a certificate of public convenience and necessity should be granted, the court said: “By these and other provisions it appears that the statutes under consideration are regulatory in nature and that all persons proposing to conduct the business of a motor carrier as defined thereby must submit themselves to the jurisdiction and control, of the Public Service Commission.” Section 3 of the act of 1931 provides: *78“The commission is hereby vested with power to regulate the business of any person engaged in the transportation as a common carrier of persons or property, either or both, for hire, by motor-vehicle on any public highway in this State.” The highways belong to the State. Stephenson v. Binford, 287 U. S. 251 (53 Sup. Ct. 181, 77 L. ed. 288, 87 A. L. R. 721). Users of them, even when engaged exclusively in interstate commerce, are subject to regulation by the State to ensure safety, convenience, and the conservation of the highways. Aero-Mayflower Co. v. Ga. Pub.-Serv. Com., 179 Ga. 431, 439 (176 S. E. 487), affirmed, 295 U. S. 285 (55 Sup. Ct. 709, 79 L. ed. 749). It is generally held that in the exercise of public functions subordinate boards or tribunals, though not created as courts, may at times exercise powers'which are judicial and at other times powers which are administrative, executive, or political. A judge of a court of general jurisdiction may sometimes act only in a ministerial capacity. It is necessary to consider the nature of the act to determine whether or not judicial powers are exercised. “It is difficult, if not impossible, precisely to define what are judicial or quasi-judicial acts, and there is considerable conflict in the decisions in regard thereto, in connection with the law as to the right to a writ of certiorari. It is clear, however, that it is the nature of the act to be performed rather than the office, board, or body which performs it, that determinés whether or not it is the discharge of a judicial or a quasi-judicial function.” 11 C. J. 121, § 68. See also Prentis v. Atlantic Coast Line, 211 U. S. 210, 227 (29 Sup. Ct. 67, 53 L. ed. 150). Before making such an examination in the present case, it may be well to set forth definitions of “judicial powers” or “judicial action.” “To adjudicate upon and protect the rights and interests of individual citizens, and to that end to construe and apply the laws, is the peculiar province of the judicial department.” Cooley on Constitutional Limitations, 184. See also Owners of Lands v. People, 113 Ill. 296; People v. Chase, 165 Ill. 527 (46 N. E. 454, 36 L. R. A. 105). “Judicial action is an adjudication upon the rights of parties who in general appear or are brought before the tribunal by notice or process, and upon whose claims some decision or judgment is rendered. It implies impartiality, disinterestedness, a weighing of adverse claims, and is inconsistent with discretion on the one hand, — for the tribunal must decide according to law and *79the rights of parties, — or with dictation on the other; for in the first instance it must exercise its own judgment under the law, and not act under a mandate from another power. The tribunal is not always surrounded with the machinery of a court, nor will such machinery necessarily make its action judicial. A county court is certainly a judicial body for some purposes, but no more so for the name, nor for the fact that it has a seal and a clerk and keeps a record. The character of its action in a given case must decide whether that action is judicial, ministerial, or legislative, or whether it be simply that of a public agent of the county or State, as in its varied jurisdiction it may by turns be each.” In re Saline County Subscription, 45 Mo. 52 (100 Am. D. 337, 338), which is widely quoted. The case of Wheeling & Elm Grove Railroad Co. v. Triadelphia, 58 W. Va. 487 (52 S. E. 499, 4 L. R. A. (N. S.) 321), contains a lengthy discussion of the question of a judicial act. As to the revocation of' a certificate, the act of 1931 (Ga. Laws 1931, p. 199) provides in section 4(d) that it may be done under different conditions. It will be observed that “The commission may, at any time after notice and opportunity to be heard and for reasonable cause, suspend, revoke, alter, or amend any certificate issued under this act or the motor-carriers act of 1929 or the motor-carriers act of 1931, if it shall be made to appear that the holder of the certificate has wilfully violated or refused to observe any of the lawful and reasonable orders, rules, or regulations prescribed by the commission or any of the provisions of this act or any other law of this State regulating and/or taxing motor-vehicles,” etc. If a hearing were had under this part of section 4(d), the commission would be dealing with a predetermined rule or regulation or law, etc., and therefore would be applying a law to a state of facts and might be said, though it is not necessary here to decide, to be engaged in a judicial proceeding or exercising judicial powers. This possibility seems to have been recognized by the General Assembly. In examining the act of 1929 (Ga. Laws 1929, p. 293), the predecessor of the act of 1931, we find that a similar provision for revocation, section 4(c), did not contain the words “and for reasonable cause.” Evidently the General Assembly took pains to insert such language in the act .of 1931 to guard against a delegation of power to the commission to act capriciously or illegally in a proceeding in which the commission would, the *80General Assembly evidently conceived, be engaged in the exercise of judicial powers, applying a rule, regulation,, or law to a presented state of facts. But with regard to the revocation of a certificate, not because of the violation of any rule, regulation, or law, but because of failure to furnish adequate service, as in its application for a certificate the motor common carrier proposed to furnish, the General Assembly provided further that “or if in the opinion of the commission the holder of the certificate is not furnishing adequate service, or if the continuance of said certificate in its original form is incompatible with the public interests.” In other words, in dealing with the paramount consideration of the grant of the certificate, that is, the convenience and necessities of the public in the use and enjoyment and protection of their highways, and fully sensible of the hardship or harm that might result from tying up the administration of the commissiqn in so vital a matter by review, the General Assembly affirmatively provided that, as to a revocation of such certificate under that part of section 4(d) last above quoted, the commission should predicate its action only upon its opinion. It can hardly be seriously asserted that thereby the delegated power involved a function of applying any “law” to a state of facts. It is one thing to provide that a thing may be done if it is made to appear that under the law a certain situation exists; it is another thing to provide that a thing may be done if in the opinion of a named party a certain situation exists. The one is justiciable; the other is administrative. “An act is none the less ministerial because the person performing it may have to satisfy himself that the state of facts exists under which it is his right and duty to perform the act.” 34 C. J. 1181, § 6. “Even where it is essential to maintain strictly the distinction between the judicial and other branches of the government, it must still be recognized that the ascertainment of facts, or the reaching of conclusions upon evidence taken in the course of a hearing of parties, interested, may be entirely proper in the exercise of executive or legislative, as distinguished from judicial, powers. The legislature, had it seen fit, might have conducted similar inquiries through committees of its members, or specially constituted bodies, upon whose report as to the reasonableness of existing rates it would decide whether or not they were extortionate and whether other rates should be established, and it might have used methods *81like those of judicial tribunals in the endeavor to elicit the facts. It is ‘the nature of the final act’ that determines ‘the nature of the previous inquiry/ Prentis v. Atlantic Coast Line, 211 U. S. 210, 227,” supra. Louisville & Nashville R. Co. v. Garrett, 231 U. S. 298, 307 (34 Sup. Ct. 48, 58 L. ed. 229). Could it be seriously contended that the General Assembly acts judicially because, before enacting a statute, it affords a hearing in a given case ? And could the Public-Service Commission be stronger than its creator, and be said to act judicially merely because it affords a hearing, either of its own design or because so directed by the General Assembly? A body does not necessarily exercise judicial powers because it may make an investigation or use discretion in acting in a given case. In Gray v. McLendon, 134 Ga. 224 (10), 258 (67 S. E. 859), it was held that “The provision in the act of 1879 of the General Assembly, creating the office of railroad commissioner, in which that body reserved to itself unlimited discretion to remove any one holding such office, does not confer on the General Assembly judicial power,” etc. It was further stated in the opinion that “The office of railroad commissioner’ was created by the legislature, and the creating power had the right to prescribe the terms upon which the office might be held. Any one accepting the office did so subject to these terms. Such person could not take the office except on the terms imposed by the act creating it. He had to accept both the office and the conditions under which it could be held, or had to reject both.” It would seem by analogy that any one who accepts a certificate of public convenience and necessity takes it with all of the conditions attached to its issuance, and that the Public-Service Commission, exercising the right of revoking the certificate when in its opinion the holder is not furnishing adequate service, is not acting judicially. In Felton v. Georgia Federation of Labor, 178 Ga. 313 (173 S. E. 662), involving the removal from office of a Public-Service Commissioner by the Governor, it was held in headnote 1 that “The orders of the Governor suspending the respondents as officers of the Public-Service Commission were in the exercise of the political powers of the executive, as conferred by the General Assembly, and in no sense a judicial action which could be reviewed by writ of certiorari.” Can there be any difference in the nature of the act of one being removed from office and in the case of a certificate of public con-*82venienee and necessity being revoked? In discussing the test of a judicial act, Mr. Justice Atkinson, in Mutual Light & Water Co. v. Brunswick, 158 Ga. 677, 681 (124 S. E. 178), said: “The real test as to the legislative or judicial character of the proceeding is not to be found in the fact of a hearing being afforded, but depends upon the subject of the inquiry — whether it is as to rates that shall be charged in the future, or whether it is as to a charge for violation of some rule already in existence. It is legislative to make a rule for future conduct, and judicial to punish for infraction of, or to enforce, an existing rule.” That statement was in a case involving the question of whether or not certiorari would lie to review the action of the Public-Service Commission in lowering electric and power rates to be charged by a municipality, and where, though contesting parties appeared before the commission and were heard, it was held that the commission was not exercising judicial powers. Justice Atkinson states that a judicial nature of a proceeding is determined by “whether it is as to a charge for violation of some rule already in existence” and that it is “judicial to punish for infraction of, or to enforce, an existing rule.” It can hardly be said that the proceeding under investigation falls into such a category. It must be assumed that the motor common carrier acquired its certificate in the manner provided by law. Section 5 of the act of 1931 provides how the application for a certificate shall be made, and section 6 provides for the hearing thereon. The applicant must, under section 5, file the application in writing and under oath, containing “full information concerning the applicant’s financial condition, the equipment proposed to be used, including the size, weight, and capacity of each vehicle to be used, and other physical property of the applicant; (c) shall state the complete route or routes over which the applicant desires to operate, and (d) the proposed time schedule of the operation,” etc. Thus it is seen that the carrier, when permitted to operate, is not doing so under any rule or regulation by the commission as to what equipment or service it should furnish, but, to speak exactly, is operating because it proposed to furnish certain equipment and service and, under such representations, has been awarded a certificate of public convenience and necessity by the commission. As provided by the act, no perpetual franchise was thereby given. When the carrier was called on to show cause why *83its certificate should not be revoked, no question of the “violation of some rule already in existence” was involved. Neither can it be said that the purpose was to “punish for infraction of, or to enforce, an existing rule.” When the certificate was revoked, the carrier merely reverted to its former status. The motive of the commission was regulatory, not punitive. Under the definition of Justice Atkinson, therefore, the proceeding before the commission was other than judicial. In Mutual Light &c. Co. v. Brunswick, supra, the court quoted approvingly from Daniels v. Commissioners of Pilotage, supra, in which it was held that a refusal by the commissioners to authorize licensed pilots to operate a boat separate and independent from the pilot boat to which all pilots were required to be attached was not the exercise of a judicial function. In the opinion in the Daniels case is cited the case of Muir v. Bardstown, 120 Ky. 739 (87 S. W. 1096), which was dealing with an act or ordinance of a municipality, but a portion of the reasoning is pertinent to the issue as to the exercise of judicial powers. In the latter case it was stated: “There must generally be two or more litigants. An issue of law or fact must be joined by them, within the jurisdiction of the tribunal, with respect to property or some personal right in which the litigants are interested. Its conclusion must be binding upon the parties until reversed or set aside in the manner provided by law for opening up judgments of courts. To hear evidence, to swear witnesses, to impanel a jury if the case admits of it, to punish for contempt, to compel parties and witnesses to attend, and finally to enter a judgment settling the matter in dispute, are the distinguishing features of a court of judicature. Master commissioners — commissioners to condemn rights of way for railroads and other pur poses — are not courts, nor are assessing officers, boards of review, or of equalization of assessments. The action of the council in assessing omitted property is purely ministerial, although it has mixed certain discretion, as to finding values, and the like, which is not reviewable, and which quality is sometimes called ‘judicial/ though it is not judicial in the sense that it is the act of a court.” On the same subject as dealt with in Muir v. Bardstown, supra, see Crowell v. Benson, 285 U. S. 22 (7) (52 Sup. Ct. 285, 76 L. ed. 598). If the refusal of a certificate, as held in the Daniels case, supra, be' not a judicial act, then, rationally, the revocation of a certificate is not one. *84It is expressly provided in section 28 of the act of 1931 that “Nothing in this or any previous act of the General Assembly shall ever be construed to vest in the 'owner or holder or assignee of any certificate of public convenience and necessity any vested right to use the public roads of this State, and shall never be construed to give to any motor common carrier any perpetual franchise oven such public roads.” “Whatever personal advantage or benefit inures to the recipient of such a certificate is an incident to the carrying out of the purpose of serving the public convenience and necessity, but is not an object of the statute.” 42 C. J. 681, § 109. It has been held that a certificate is not an asset with which a receiver may be charged. Easterbrook v. Public Utilities Commission, 112 Ohio St. 417 (147 N. E. 761). The following are some instances in this State where it has been held that certain investigations and actions did not involve the exercise of judicial power's: It has been repeatedly held by this court that judges of superior courts and ordinaries, as the case may be, do not act judicially in deciding election contests. They exercise discretion and judgment and at times must determine issues of fact, but do not in such undertakings exercise judicial powers, though the same person may at other times, when acting as a court, exercise such powers. In Justices of the Inferior Court of Lee County v. Hunt, 29 Ga. 155, it was held that the justices of _ the inferior court were not acting judicially in issuing execution against a county treasurer and his sureties. In Meadows v. Taylor, 82 Ga. 738 (10 S. E. 204), it was held that an ordinary’s action upon a petition to make the stock law operative in a certain militia district was not judicial, and certiorari would not lie. In Bowen v. Clifton, 105 Ga. 459 (31 S. E. 147), it was held that the Secretary of State in hearing and determining contests of elections held for the purpose of deciding whether county sites should be removed does not act judicially. In Harris v. Glenn, 141 Ga. 687 (81 S. E. 1103), it was held that the ordinary, in determining a contest as to election of municipal officers, does not act judicially. (Citing.) In Bower v. Bainbridge, 116 Ga. 794 (43 S. E. 67), it was held that certiorari does not lie to the decision of the mayor and aldermen' in determining the value of property for the purpose of assessing taxes. In Cily Council of Augusta v. Loftis, 156 Ga. 77 (118 S. E. 666), a fuling of the board of health on appeal to review a ruling of a *85plumbing inspector was held not to be a judicial act, and that certiorari would not lie. A number of decisions of this court have been brought to our attention from which it is urged that by analogy the action of the Public-Service Commission should be held to be in the exercise of judicial powers. We distinguish their inapplicability, as follows: In Mayor &c. of Macon v. Shaw, 16 Ga. 172, a charge of “malpractice” by gambling was preferred against a city marshal, and he was tried. Here was the exercise of judicial powers by a tribunal acting as a court, applying to the facts presented at the trial, in a quasi-criminal proceeding, a previously enacted ordinance. Naturally this court held that the mayor and council were acting as a judicatory. It is, of course, provided by statute that the writ of certiorari will lie to review the action of an inferior judicatory. In Asbell v. Brunswick, 80 Ga. 503 (5 S. E. 500), the removal of a police officer was involved, and a trial was had under the terms of the act of 1872 which expressly provided that the mayor and aldermen might, at their discretion, remove an officer for breach or neglect of duty. But a trial was had after charges had been preferred. Six aider-men sai as a court. This court held that it was error to hold that the alderman acting as mayor pro tern, could not vote, and that upon a petition for certiorari alleging such error (involving a point of law) the writ should have been granted. In Gill v. Brunswick, 118 Ga. 85 (44 S. E. 830), a policeman was tried for misconduct, under authority of the act of 1900, p. 240, providing that no officer should be removed except upon arraignment or accusation, and that the mayor and aldermen should have authority to subpoena witnesses and punish for contempt, and plainly providing for a trial, a quasi-criminal proceeding, the mayor and aldermen applying a law to a presented state of facts and thereby acting judicially. In Carr v. Augusta, 124 Ga. 116 (52 S. E. 300), an ordinance provided that any liquor dealer should forfeit his license in case the holder be convicted in any court of competent jurisdiction of a violation of any Federal, State, or municipal regulation governing the sale of liquor. A hearing was granted before a resolution was passed declaring the license of a dealer forfeited. The municipal council was trying the issue under the ordinance and the presentation of facts in a judicial capacity, and not revoking the license at their independent discretion as they might *86have clone. In Tibbs v. Atlanta, 125 Ga. 18 (53 S. E. 811), a trial was had before the board of police commissioners on preferred charges. The proceeding involved the application of law to presented facts, a judicial investigation. In Atlanta & West Point Railroad Company v. Redwine, 123 Ga. 736 (51 S. E. 724), the commission was proceeding under a statute to lay out and open a public road, and providing that they should sit as a court. The railroad filed a petition for injunction, which was denied. This court said that a landowner, if he desired to object to the action of the commissioners, should have appeared, in response to notice, before the commissioners and urged his objections, and “Had the commissioners differed with the company as to the law respecting their power to lay out a public road longitudinally upon fits right of way, the company could avail itself of its remedy by certiorari to review the finding. Why? Because the commissioners, in such a case, would have been trying the rights of the landowner and applying the law, sitting as a court and exercising judicial powers. In Dixon v. Sable, 147 Ga. 623, 624 (95 S. E. 240), it was merely held that the city court of Savannah, though a constitutional court, was an inferior judicatory, and that certiorari would lie. In Ballard v. Jones, 148 Ga. 513 (97 S. E. 443), it was held that certiorari would lie to reach a proceeding before county commissioners where a landowner’s rights were involved and he appeared and urged legal objections against the establishment of the road. Obviously, such a proceeding, involving private rights under the law, would have been judicial. In City of Atlanta v. Blackman Health Resort, supra, written objections had been filed by adjacent property owners against the issuance of a building permit. The hearing involved a contest of property rights between different parties, and proceeded under section 629 of the then Code of the City of Atlanta providing for a hearing and judgment. Clearly such section provides for the exercise of judicial powers. We believe that enough of such cases have been discussed to show that they do not afford analogies for any holding that the writ of certiorari should lie to review a finding of fact by the Public-Service Commission. They were cases in which previously enacted ordinances or laws were applied to presented evidence. While it is not necessary so to decide here, it would seem that in the municipal council cases the writ would lie, without reference to whether the *87proceeding was judicial, inasmuch as by statute it is provided that the writ will lie to review the finding of such corporation courts or councils. It will perhaps make clear the distinction as to when the writ will lie to a board’s action and when it will not, if we consider the cases of Leathers v. Furr, 62 Ga. 421, and Hudson v. Sullivan, 93 Ga. 631 (20 S. E. 77), both of which were proceedings before commissioners. In the first case Leathers filed a petition with the county commissioners to cause Eurr to remove obstructions from a private way claimed by the petitioner. Eurr sought certiorari in the superior court. Leathers moved to dismiss. The motion was overruled, the certiorari was sustained, and Leathers excepted. This court held that a writ of certiorari would lie to review an error of the commissioners in ordering the private way opened. Here is a case which one might mistakenly urge as authority for the issuance of the writ to review the finding of the Public-Service Commission in the present case. But in the Hudson case, supra, in which Hudson and others sought to review by certiorari the action of the county commissioners in changing the line between two militia districts, the Leathers case is distinguished. In the Hudson case error was assigned on the refusal .of the judge to sanction the petition for certiorari. This court upheld the judge, and said: “The case of Leathers v. Furr, 62 Ga. 421, relied on by counsel for the plaintiffs in error, is not at all like the present case. That case involved litigation between two individuals concerning a private way, the one alleging a right to the use of the way and seeking to have obstructions removed therefrom, and the other denying and contesting this right.” In the first case the rights of contesting parties were involved, and the commissioners were exercising judicial powers. In the second case they were exercising only a political or executive power. In the one case the writ would lie; in the other it would not. In Hillsman v. Harris, 84 Ga. 432, 436 (11 S. E. 400), referred to in the opinion in the Hudson case, the first headnote is: “It would seem that the action of the ordinary in changing district lines is final and not subject to review by writ of certiorari or otherwise. The district lines mark the territorial divisions of a county, and the power of establishing and changing them is in its nature political or legislative rather than judicial.” In the opinion Chief Justice Bleckley said: “The work of changing the lines of militia *88districts is political rather than judicial in its nature, these districts being the political divisions oJE a county, and sustaining with reference to the county a relation somewhat like that which the counties sustain to the State. We doubt, therefore, whether it is in the power of the superior court to substitute by judgment upon a certiorari, or otherwise, its opinion for that of the ordinary as to the necessity and expedient location of district lines.” The principles ruled in that ease, and the reasoning, apply with equal force to the question here presented. The commission, acting in a governmental capacity, is composed of persons supposed to be experts in their particular field, and we should hesitate to hold-that the scope of the writ of certiorari should be so broadened as to extend to a review of its finding of fact by a court, which in its very nature is not equipped to make the investigation that becomes necessary in the discharge of the duties imposed upon them under section 4(d) of the act of 1931 and under which the commission proceeded. The reasoning of Chief Justice Bleckley brings us close to that question. There is no suggestion of applying any law, rule, or regulation to a state of facts involving a judicial function, but only an investigation or “inquisition” as to a fact, in the determination of which the only test was the opinion of the commission, right or wrong, as contradistinguished from a justiciable issue. In Degge v. Hitchcock, 229 U. S. 162 (33 Sup. Ct. 639, 57 L. ed. 1135), the Postmaster-General issued an order depriving a certain corporation of the use of the mails, on the ground that it had used the mails for fraudulent purposes. The corporation filed in the Supreme Court of the District of Columbia a petition for certiorari, which was dismissed by the court. The Court of Appeals, without passing on the right to issue the writ, affirmed the decision on the ground that the finding by the Postmaster-General was supported by the evidence. In the United States Supreme Court the government renewed in argument its contention that the district court was without jurisdiction to issue the writ, and the Supreme Court held that it would not lie, saying on page 171 : “The appellant insists that under these common-law principles the writ should issue here, because, having to act ‘upon evidence satisfactory to him’ (Rev. Stat. § 3929), and notice and a hearing having been given, the Postmaster-General acted in a judicial capacity in making the order, which was therefore subject to re*89view on certiorari, because he exceeded his jurisdiction, and, without any proof of fraud in the use of the mails, deprived plaintiffs in error of the valuable right to receive letters and money through the post-office. It is true that the Postmaster-General gave notice and a hearing to the persons specially to be affected by the order, and that in making his ruling he may be said to have acted in a quasi-judicial capacity. But the statute was passed primarily for the benefit-of the public at large, and the order was for them and their protection. ' That fact gave an administrative quality to the hearing and to the order, and was sufficient to prevent it from being subject to review by writ of certiorari. The Postmaster-General could not exercise judicial functions, and in making the decision he was not an officer presiding over a tribunal where his ruling was final unless reversed. Not being a judgment, it was not subject to appeal, writ of error, or certiorari. Not being a judgment, in the sense of a final adjudication, the appellants were not concluded by his decision, for had there been an arbitrary exercise of statutory power of a ruling in excess of the jurisdiction conferred, they had the right to apply for and obtain appropriate relief in a court of equity.” Citing American School of Magnetic Healing v. McAnnulty, 187 U. S. 94 (23 Sup. Ct. 33, 47 L. ed. 90); Philadelphia Co. v. Stimson, 223 U. S. 605, 620 (32 Sup. Ct. 340, 56 L. ed. 570). (Italics ours.) In the present case the Public-Service Commission, in the interest of the public, called upon the motor common carrier to show cause why its certificate, issued subject to the future orders of the commission, should not be revoked for failure to furnish adequate service, and the commission reached the opinion that, for the public convenience and necessity, the certificate should be revoked. Let it be borne in mind that we are not holding that the carrier is in all events remediless. We address ourselves to the applicability of the writ of certiorari. If in a given case the commission should act beyond its powers or capriciously or fraudulently, that is another matter. The courts of equity, as stated in the Degge case, supra, are always open for the redress of wrongs upon a proper occasion, but what we here announce is that we will not by construction broaden the scope of the writ of certiorari, and especially in those circumstances where it is sought to review the finding of a tribunal acting, not in a judicial capacitjr, but as a proper *90and lawful medium for safeguarding and protecting what is the paramount object of its creation, the interest and welfare of the public in the use and maintenance of its highways. In such a consideration the benefit to a particular licensee is only incidental, and the certificate is expressly declared by the statute itself to confer no vested right. The investigation by the commission was to determine, in the paramount interest of the public in the use and enjoyment of its highways, whether or not the holder of the certificate had abandoned the passenger service it had promised to operate and whether its certificate should be revoked. There was no trial of the holder of the certificate. The investigation was not, as a trial is usually declared to be, in its ordinary and accepted meaning, “the judicial investigation and determination of issues between parties.” 7 Words and Phrases (3rd Series), 622. No vested right of the holder was being tried. No contest between parties was being heard. Under all of the definitions of judicial power hereinbefore set forth, we construe the revocation of the certificate under the circumstances as not involving the exercise of judicial powers. The grant of the certificate was the exercise of administrative or legislative power, and the revocation of the certificate was the exercise of a power of the same character. Therefore the question certified by the Court of Appeals is answered in the negative.
All the Justices concur, except Russell, C. J., and Bell, J., who dissent.