delivered the opinion of the Court:
This is clearly an instance of judicial interference with the discretionary power of an executive officer of the government. It is elementary that a court is powerless to direct the action of an executive officer unless a positive legal right is being invaded by the officer, where the duty imposed upon him is clearly prescribed and enjoined by law. The duty, however, must be so plain and positive that the officer has no discretion left. Merrill, Mandamus, p. 64.
The Commissioner of Patents is vested with full authority to control and regulate the course of proceedings in his office. If, in his judgment, action on a pending application should be suspended temporarily, for what he deems a sufficient reason, so long as such suspension does not interfere with a positive legal right a court will not inquire into the wisdom of his action. "We recognize the well-established principle that courts will intervene to protect the citizen when his constitutional or legal rights are being invaded by the exercise of arbitrary power. Where an officer, acting under assumed authority vested in him by virtue of his office, undertakes in the performance of his official duties, without due process of law, to deprive the citizen of rights he has acquired by administrative or judicial proceedings, the courts will afford protection, either by mandamus or injunction. In this case, no such right has been invaded. The hearing of the eases has simply been postponed for reasons clearly within the discretion of the Commissioner, and all the rights of appellee are protected. The appellee has not been deprived of any legal right conferred by law. The Commissioner of Patents filed in his office the assignment executed by virtue of the decree of the supreme court of New York. The decree not bnly imposed no duty upon the Commissioner, but it is not even persuasive as to how, or when, or to whom the patents in this case shall be issued. “The full faith and credit clause” of the Constitution has not been violated by the Commissioner. It does not in any way enter into this case. It is therefore unnecessary for us to consider whether or not that clause relates *248to executive officers of the government, or is confined exclusively to the courts. What the supreme court of New York did was to direct the execution of an assignment of the Berger applications to appellee. The Commissioner has not questioned the validity of the action of the court or the assignment. He has merely suspended further action on the applications until the case in New York, now pending on appeal, is finally determined. This, in our opinion, was not only a due exercise of discretion, but it was prudent action on the part of the Commissioner. Had he permitted appellee to prosecute the applications to patent, or even to examine the applications and secure copies of them, and the decree should be afterwards reversed, irreparable damage might, or almost certainly would, result to the Metropolitan Sewing Machine Company. On the other hand, should the decree of the court be affirmed, there is no law compelling the Commissioner to recognize the assignment. It is no part of the duty of the Commissioner to pass upon the validity or invalidity of assignments filed in his office. Whether he recognizes the assignment, or not, will not affect the legal status of appellee as fixed by the decree of the New York court.
It is well settled that it is purely discretionary with the Commissioner whether he shall issue the patent to the assignee or the patentee. As said by this court in a case where there were two assignments filed in the Patent Office: “Having determined that a patent should issue, it is conceded he might have ignored both assignments and issued a patent in the name of the inventor, which, probably, would have been the better course for him to have followed.” Re Pearsall, 31 App. D. C. 265. Should the decree be affirmed, and the Commissioner finally determine that patents should he issued upon the applications in this case,— which yet remains to be decided, — it is discretionary with him whether they shall be issued to the inventor Berger or to the assignee. No damage can occur to the appellee as a result of the exercise of such discretion on the part of the Commissioner. Appellee is fully protected by his assignment. The patents are equally valid, whether issued in the name of the applicant or the assignee, and, when issued, the title immediately vests, by *249operation of law, in the assignee. Gayler v. Wilder, 10 How. 477, 13 L. ed. 504.
Upon no theory is there a case here presented for the interference of the courts. The extraordinary writ of mandamus is not available for this purpose. The order is, therefore, reversed, with costs and cause remanded, with directions to vacate such order, to discharge the rule to show cause and to dismiss the petition, and it is so ordered. Reversed.
On motion of the appellant a writ of error to the Supreme Court of the United States was allowed January 14, 1909.