The United States Constitution declares that "The privilege of the writ of habeas corpus shall not be suspended, unless when in cases of rebellion or invasion the public safety may require it." 30 The implication from this language is that the writ shall not be suspended, except in the cases mentioned. The prohibition is directed only to the Federal Government. Aside, therefore, from the specific provisions of their several constitutions, the States are free to suspend the writ, but in case they do so and without sufficient excuse, the person detained may, of course, obtain the writ from a federal court under the claim that he is deprived of liberty without due process of law.

The suspension of the privilege of the writ, it is to be observed, does not deprive the courts of the right to issue it. It furnishes merely a legal ground for a refusal to obey it.31

Furthermore, the suspension of the writ goes no further than to justify this refusal. It thus enables executive agents to make arrests at will, and, while the suspension is in force, renders it impossible for those apprehended to obtain a judicial judgment upon the legality of such arrests and detention. But it does not operate actually to authorize such arrests,32 or to deprive the individual of any of the other rights which the law secures him, and, therefore, the persons responsible for the arrests and detention may still be held civilly and criminally responsible for any illegal acts that they may have committed. In time of war, or of domestic insurrection "or disorder, when so-called martial law has teen declared, the privilege of the writ of habeas corpus, together with all the other civil guarantees may, for the time being, be suspended; but, as we have already learned in the preceding chapter, actual public necessity, and this alone, will furnish legal justification for this.

28 But not of course, for the petition must set out a cause for its issuance.

29 The jurisdiction of the. federal courts with reference to the issuance of the writ has been considered in an earlier chapter. Chapter VIII (Maintenance Of Federal Supremacy By Habeas Corpus To State Authorities. 68. State Courts May Not Interfere With Federal Authorities).

30 Art. I, Sec. 9, CI. 2.

31 Ex parte Vallandigham, I Wall. 243; 17 L. ed. 589.

32 The four minority justices in the Milligan case asserted, though, it would seem improperly, that the suspension of the writ does have this effect.

The existence of civil war. operates as regards the enemy ipso facto, that is, without formal declaration, as a suspension of the privilege of the writ of habeas corpus, together with, as said, the suspension of the other guarantees to the individual against arbitrary executive action. In the preceding chapter the principle was sustained that the establishment of martial law may properly take place not only upon the theater of active hostilities, but elsewhere when the actual necessities of the case demand it.

The suspension of the privilege of the writ of habeas corpus falls short of the establishment of martial law, but to justify it there is required the same public necessity as that required for the enforcement of martial law. The same reasoning, therefore, that was employed with reference to this latter subject is applicable to the question of the suspension of the writ of habeas corpus, and need not here be repeated.