Lead Opinion

Mr. Justice Morris

delivered the opinion of the Court:.

The principal question here, as in all eases of this character, is whether the act sought to be performed is of a ministerial or *597of a judicial character, as those terms have been defined and limited by the courts. For, as pointed out in the case of United States ex rel. West v. Hitchcock, 19 App. D. C. 333, there is no ministerial act to which the writ of mandamus would be applicable that does not in some measure and to some extent involve the exercise of judgment and discretion, and there are acts apparently judicial which are not so in contemplation of law. An act may be ministerial in this connection, although it may occur in the course of judicial proceedings, or iu the exercise of discretionary power, when it is merely a ministerial thing to be done after the judicial authority over the subject-matter has been exercised. Such was the matter of the issue of a patent in the case of Butterworth v. Hooe, 112 U. S. 50; the approval of an allotment of land in the case of United States ex rel. West v. Hitchcock, 19 App. D. C. 333, and similar acts in other cases which can readily be recalled.

It is very clear that the Congress of the United States has not committed to the Postmaster-General, or to any one else, the matter of determining what should be carried in the mails as second-class matter, and what as matter of the third class. It has reserved that power exclusively to itself. It has itself made the classification; and it is not competent for the Postmaster-General to add anything to the statute or to take anything from it. It may be that the classification has not been made with all the definiteness that is desirable. It may be, even, that the privilege of the mails has been grossly abused by the introduction into them of mail matter of the second class which was never anticipated by Congress. If, as alleged in the pleadings, the cost of transmission of the relator’s periodical through the mails as second-class matter has been only forty cents per number a year, and the cost of such transmission to the Government has been two dollars a year, while the cost of its transmission as third-class matter is the sum of three dollars and twelve cents a year, there would seem to he some inequality with which Congress should deal; yet it is not the province of the Postmaster-General to *598remedy the evil, if evil there is, by a postal regulation, or by unwarranted interpretation of the law.

The citizen who desires to have his publication carried in the mails of the United States as second-class mail matter, and who has fully and fairly complied with all the requirements of the statute in regard thereto, has acquired a positive legal right to have it so carried; and his right will be enforced by the writ of mandamus, if the Postmaster-General arbitrarily or without valid legal reason refuses to receive and transmit such publication. Of course the Postmaster-General and his subordinates are required to use judgment and discretion, and it may sometimes be a matter of much difficulty to identify a publication as one included in the category prescribed by Congress. But their discretion is limited to this question of identification; and it is not competent for them to impose additional requirements beyond those specified in the statute.

The postal regulation of July 17, 1901, under which it was sought to exclude the relator’s publication from the category of second-class mail matter, is clearly in excess of the statute. It prescribes conditions which the statute does not prescribe. It is provided by the statute that periodical publications, in order to be admitted as second-class mail matter, " must be originated and published for the dissemination of information of a public character, or devoted to literature, the sciences, arts, or some special industryThe regulation restricts such publications to “ such as consist of current news or miscellaneous literary matterIt wholly omits and excludes periodicals devoted to the sciences, arts, or some special industry. Now, it may be that the words " miscellaneous literary matter ” might be construed to mean the same thing as periodicals -7 devoted 'to- literature ”; but certainly current news ” is not the equivalent of " information of a public characterThe regulation would restrict 'the second-class mail matter to the daily and weekly papers which disseminate " current news ”; but undoubtedly' the information conveyed by the relator’s guide, a copy of which has been filed in the proceedings as an exhibit, is informa*599tion of a public character, most useful not only to those immediately connected with the railroad and steamboat transportation of the country, but likewise to the traveling public. And yet this is excluded by the regulation.

It is true that the regulation also provides that the publications to be admitted as second-class mail matter shall “ conform to the statutory characteristics of second-class matter.” But if the regulation means anything at all, or is intended to have any meaning, it is to superadd to the statutory characteristics another or other requirements not prescribed by the statute. This cannot lawfully be done.

What the Supreme 'Court of the United States said in the case of Morrill v. Jones, 106 U. S. 466, is applicable here. It appeared in that case that an act of Congress authorized the importation into the United States free of duty, of “ animals alive, specially imported for breeding purposes from beyond the seas ”; and that the Secretary of the Treasury, construing the act for himself, published a treasury regulation whereby he instructed collectors, that before admitting such animals from abroad, they should be satisfied that the animals were of superior stock, and adapted to improve the breed in this country. The Supreme Court said, in regard to this regulation:

“ The Secretary of the Treasury cannot, by his regulations, alter or amend a revenue law. All he can do is to regulate the mode of proceeding to carry into effect what Congress has enacted. In the present case we are entirely satisfied that the regulation acted upon by the collector was in excess of the power of the secretary. The statute clearly includes animals of all classes. The regulation seeks to confine its operation to animals of ‘ superior stock.’ This is manifestly an attempt to put into the body of the statute a limitation which Congress did not think it necessary to prescribe. Congress was willing to admit, duty free, all animals specially imported for breeding purposes; the secretary thought this privilege should-be confined to such animals as were adapted to the improvement of breeds already in the United States. In our opinion, the object of the secretary could only be ac*600complished by an amendment of tbe law. That is not the office of a treasury regulation.”

The Postmasters-General, who for many years have been appealing to Congress for some remedy for what they designate as an abuse of the second-class mail matter system, seem also to have been of opinion that they were without authority to remedy the evil by a postal regulation. It is unnecessary for us, in the present case, to decide how far their action and their view and construction of the law are binding, if at all, upon their successors. But even if we assume that the matter now comes up for consideration for the first time, and that the Postmaster-General is now for the first time called upon to make regulations to carry the statute into effect, we are clearly of opinion that the postal regulation of July 1Y, 1901, so far as it assumes to add to the requirements of the statute in regard to second-class mail matter, is in excess of his authority, and of no validity in law.

It is conceded that the relator has complied with all the requirements of the statute, and that the characteristics of its publication are literally and specifically as therein prescribed; and it appears that the exclusion of the periodical from the mails as second-class matter is based exclusively and in express terms upon its failure to comply with the superadded requirement of the postal regulation that it must “ consist of current news.” Under the doctrine of the cases of Butterworth v. Hooe, 112 U. S. 50; United States v. Schurz, 102 U. S. 378; Dunlap v. Black, 128 U. S. 40; Roberts v. United States, 176 U. S. 221; American School of Magnetic Healing v. McAnnulty, at the present term (October, 1902) [187 U. S.] ; United States v. Hitchcock, 19 App. D. C. 333, and other eases, we must hold that the ground of exelusion is insufficient in law, and that the relator is entitled to the writ of mandamus for the enforcement of its right in the premises.

Very greatly to the point is the case just cited of the American School of Magnetic Healing v. McAnnulty, decided November 17, 1902, by the Supreme Oourt of the United States at its present term. There the Postmaster-General of the *601United States, called upon to construe and enforce the act of Congress of September 19, 1900, to prevent the use of the mails for the collection of money by false and fraudulent devices, directed the exclusion from the mails of letters addressed to or intended for the American School of Magnetic Healing, an organization established at Nevada, in the State of Missouri, for the cure of all human ailments by mental or magnetic processes. There was great plausibility in his course; and he was undoubtedly called upon to exercise a certain amount of judgment and discretion in the application of the law. But the Supreme Court, by Mr. Justice Peokham, said;

“ That the conduct of the post-office is a part of the administrative department of the Government is entirely true, but that does not necessarily and always oust the courts of jurisdiction to grant relief to a party aggrieved by any action of the head or one of the subordinate officials of that department which is unauthorized by the statute under which he assumes to act. The acts of all its officers must be justified by some law, and in case an official violates the law to the injury of an individual the courts generally have jurisdiction to grant relief.

“ * * * Here it is contended that the Postmaster-General has, in a case not covered by the acts of Congress, excluded from the mails letters addressed to the complainants. His right to exclude letters, or to refuse to permit their delivery to persons addressed, must depend upon some law of Congress, and if no such law exist then he cannot exclude or refuse to deliver them. Conceding, arguendo, that when a question of fact arises, which, if found in one way, would show a violation of the statutes in question in some particular, the decision of the Postmaster-General that such violation had occurred, based upon some evidence to that effect, would be conclusive and final, and not the subject of review by any court, yet to that assumption must be added the statement that if the evidence before the Postmaster-General, in any view of the facts, failed to show any violation of a Federal law, the determination of that official that such violation ex*602isted would not be the determination of a question of fact, but a pure mistake of law on his part, because the facts being conceded, whether they amounted to a violation of the statutes, would be a legal question, and not a question of fact. Being a question of law simply, and the case stated in the hill being outside of the statutes, the result is that the Postmaster-General has ordered the retention of letters directed to the complainants in a case not authorized by those statutes. To authorize the interference of the Postmaster-General, the facts stated must in some aspect be sufficient to permit him under the statutes to make the order.

“ The facts, which are here admitted of record, show that the case is not one which by any construction of those facts is covered or provided for by the statutes under which the Postmaster-General has assumed to act, and his determination that those admitted facts do authorize his action is a clear mistake of law as applied to the admitted facts, and the courts, therefore, must have power in a proper proceeding to grant relief. Otherwise, the individual is left to the absolutely uncontrolled and arbitrary action of a public and administrative officer, whose action is unauthorized by any law and is in violation of the rights of the individual. Where the action of such an officer is thus unauthorized he thereby violates the property rights of the person whose letters are withheld. * * *

“ * * * Although the Postmaster-General had jurisdiction over the subject-matter (assuming the validity of the acts) and therefore it was his duty upon complaint being made to decide the question of law whether the case stated was within the statute, yet such a decision being a legal error does not bind the courts.”

It seems to us that this case is decisive of that now before us.

The order appealed from will therefore be affirmed, with costs, and the cause will be remanded to the Supreme Court of the District of Columbia to carry the same into effect. And it is so ordered.

Dissenting Opinion

Mr. Justice Shepard

dissenting:

Demands upon my time permit only a brief statement of the reasons why I cannot yield my assent to the judgment awarding the writ of mandamus in this case.

I am not unmindful of the weight that ought to be given, not only by the courts but by the succeeding heads of executive departments, to the long-continued practice of a department involving the interpretation of a law prescribing its regularly recurring duties in respect of the administration of an agency intrusted to it. But that the head of such a department has the right, in his own administration, to reverse the practice of his predecessors whenever, in his judgment, that practice has not been founded on a correct interpretation •of the law, I have no doubt.

Save as to a subject-matter _ finally closed and settled under the former practice, and which thereby takes on the nature of a vested right of property, the rulings on which that practice is founded contain no element of estoppel or res judicata as the doctrines thereof are applicable in judicial proceedings.

It is proper to say here, however, that this proposition is not denied in the opinion of my brethren.

I agree that where the law directs the performance of a •specific act, the facts of which are plain, the executive officer cannot escape the obligation by raising a question of construction merely: his duty does not cease to be ministerial because, to some slight extent, he must give interpretation to the law. This is what I understand to be the salutary doctrine enounced in Roberts v. U. S., 176 U. S. 221; S. C., Roberts v. Valentine, 13 App. D. C. 38.

But when the ruling of the departmental chief does not involve a mere question of obedience to a law commanding in reasonably plain terms a duty to be performed in a particular case, and necessarily requires investigation of the special facts relating to each particular case that shall be presented for the application of a law couched in general terms, a very different condition arises.

*604A discretionary duty is then imposed, and its exercise is not subject to judicial control: it is only politically examinable and parties aggrieved must look to tbe legislative branch for relief.

I do not consider that Ave are called upon, in this case, to determine Avhether tbe item of tbe new regulation relating to mail matter of tbe second class, is narrower than tbe terms of tbe statutes justify; because tbe Postmaster-General, on tbe appeal from tbe decision of bis assistant, based bis decision, not upon tbe regulation as expressing tbe entire meaning of tbe law, but upon tbe broad ground that tbe facts showing tbe nature, purposes, ■ and manner of publication of relator’s alleged periodical did not bring it witbin tbe privilege of tbe law. In my opinion, tbe duty of determining Avbetber tbe railway guide was, under all these facts, a periodical publication of tbe second class as defined in sections 12 and 14, or one of tbe third class as defined in section II of the statute, was not ministerial simply, but quasi judicial.

Tbe Congress did not deem it advisable to admit all of tbe periodical publications of tbe country to tbe second-class mail privilege. On tbe other band it did not define with perfect precision tbe line of separation between those admitted and those excluded. When, therefore, a new publication is presented for carriage at second-class rates, tbe Postmaster-General is bound to make inquiry and pass upon tbe right. This necessarily involves tbe exercise of discretion.

Were it in our power to review bis decision in tbe present case, I would not be prepared to say that it was erroneous — at least not clearly so.

There are two general kinds of periodicals mentioned in tbe statutes; one belongs to tbe second class, tbe other to tbe third.

Tbe railway guide is not necessarily a periodical of tbe second class, although it conforms to tbe conditions of tbe first, second, and third clauses of section 14. Coming tben to tbe fourth clause, though it has a legitimate subscription list it is not “ devoted to literature, tbe sciences, arts, or some special industry.” Its claim depends, tben, upon whether it “be originated and published for tbe dissemination of *605information of a public character.” It does contain information for those who travel beyond the limits of local transportation lines; but whether this limited use by only a part of the public, and a relatively small part, answers the requirement of the statute is a subject of grave doubt, to say the least.

Granting the value of the book — for such it practically is — as one of reference for those engaged in general or distant travel, it must nevertheless be borne in mind that the succeeding numbers published and mailed, do not, like the ordinary periodical of subscription issue, consist of entirely new matter for the information of the public.

The great bulk of the matter carried from date to date of successive issue is old. Most of it has been carried time and again and delivered to the Same subscribers; for all that the later issue undertakes to do is to note such changes in schedules, or such new ones as may have occurred since the next preceding issue.

Without pursuing the subject further, I am of the opinion that the judgment should be reversed and the petition dismissed.

A writ of error to the Supreme Court of the United States was prayed and allowed.