Mr. Justice Peckham,
after making the foregoing statement of facts, delivered the opinion of the court.
We have set out in the foregoing statement of facts, at very great length, a large portion of the contents of the petition and answer in this case. It has been done for the purpose of showing by the record itself the questions of law arising therefrom. Upon a per.usal of the record it appears that those questions are not merely formal ones nor are they so plain as not to require the careful judgment of any tribunal to which they u be referred for decision,' Their solution was properly submiUw to the Land Department, which had full and complete jurisdiction over the matters arising under the act of June 4, 1897, and it thereby became the duty of the officers of that department to decide them. As is said in Knight v. United States Land Association, 142 U. S. 161:
"The Secretary is the guardian of the people of the United States over the public lands. The obligations of his oath of office oblige him to see that the law is carried out, and that none, of the public domain is wasted or is disposed of to a party not entitled to it. He represents the Government, which is a party in interest in every case- involving the surveying and disposal of the public lands."
Congress has constituted the Land Department, under the supervision and control of the Secretary of the Interior, a special tribunal with judicial functions, to which is confided the execution of the laws which regulate the purchase, selling and care and disposition of the public lands.
Neither an injunction nor mandamus will lie against an officer of the Land Department to control him in discharging an official duty which requires the exercise of his judgment and discretion. Marquez v. Frisbie, 101 U. S. 473; Gaines v. Thompson, 7 Wall. 347; United States v. Black, 128 U. S. 40; United States v. Window, 137 U. S. 636.
In Decatur v. Paulding, 14 Pet. 497, it was held that, in general, the official duties of the head of one of the executive departments, whether imposed by act of Congress or by resolution, are not mere ministerial duties. The head of an executive department of the Government in the administration of the various and important concerns of his office is continually re--quired to exercise judgment and discretion. He must exercise his judgment in expounding the laws and resolutions of Congress under which he is from time to time required to act.
That the decision of the questions presented to the Secretary of the Interior was no merely formal or ministerial act is shown beyond the necessity of argument by a perusal of the foregoing' statement of the issues presented by this record for the decision of the Secretary. Whether he decided right or wrong, is not the question. Having jurisdiction to decide at all, he had necessarily jurisdiction, and it was Ms duty to decide as he thought the law was, and the courts have no power whatever under those circumstances to review his determination by mandamus or injunction. The court has no general supervisory power over the officers of the Land Department, by which to control their decisions upon questions within their jurisdiction; If this writ were granted we would require the Secretary of the Interior to repudiate arid disaffirm a decision which he rer garded it his duty to make in the exercise of that judgment which is reposed in him by law, and we should require him to come to a deterrnination upon the issues involved directly opposite to that which he had reached, and which the law conferred, upon him the jurisdiction to make. Mandamus has never been regarded as the proper writ to control the judgment and discretion of an officer as to the decision of a matter which the law gave him the power and imposed upon him the duty to decide for himself. The writ never can be used as a substitute for a writ of error. Nor does the fact that no writ of error will lie in such a case as this, by which to review the judgment of the Secretary, furnish any foundation for the claim that mandamus may therefore be awarded. The responsibility as well as the power rests with the Secretar}*, uncontrolled by the courts.
Neither the case of Roberts v. United States, 176 U. S. 221, nor that of American School of Magnetic Healing v. McAnnulty, 187 U. S. 94, decides anything opposing these views.
In the Roberts case it was simply decided that the duty of the Treasurer to pay the money in question in that case was ministerial in its nature and should have been performed by him on demand, and that, therefore, mandamus was the proper remedy for his failure to do it.
In the McAnnulty case it was held that the order of the Postmaster General to the postmaster in the city of Nevada, not to deliver the mail to the relator, was not a justification for Such refusal, because the order was given without authority of law, and the postmaster could, notwithstanding such order, be compelled by mandamus to do his duty and deliver the mail. The case has no relevancy to the one in hand.
We are so clearly of opinion, that the decision of the defendant in this case was judicial in its nature that further argument upon the subject is needless.
The judgment of the Court of Appeals of the District of Columbia is
Affirmed.