—Justice David Davis, Ex parte Milligan (71 U.S. 2), 1866
Time has proven the discernment of our ancestors; for even these provisions, expressed in such plain English words, that it would seem the ingenuity of man could not evade them, are now, after the lapse of more than seventy years, sought to be avoided. Those great and good men foresaw that troublous times would arise, when rules and people would become restive under restraint, and seek by sharp and decisive measures to accomplish ends deemed just and proper; and that the principles of constitutional liberty would be in peril, unless established by irrepealable law. The history of the world had taught them that what was done in the past might be attempted in the future. The Constitution of the United States is a law for rulers and people, equally in war and in peace, and covers with the shield of its protection all classes of men, at all times, and under all circumstances. No doctrine, involving more pernicious consequences, was ever invented by the wit of man than that any of its provisions can be suspended during any of the great exigencies of government. Such a doctrine leads directly to anarchy or despotism, but the theory of necessity on which it is based is false; for the government, within the Constitution, has all the powers granted to it which are necessary to preserve its existence; as has been happily proved by the result of the great effort to throw off its just authority.
…All other persons, citizens of states where the courts are open, if charged with crime, are guaranteed the inestimable privilege of trial by jury. This privilege is a vital principle, underlying the whole administration of criminal justice; it is not held by sufferance, and cannot be frittered away on any plea of state or political necessity. When peace prevails, and the authority of the government is undisputed, there is no difficulty of preserving the safeguards of liberty; for the ordinary modes of trial are never neglected, and no one wishes it otherwise; but if society is disturbed by civil commotion—if the passions of men are aroused and the restraints of law weakened, if not disregarded—these safeguards need, and should receive, the watchful care of those intrusted with the guardianship of the Constitution and laws. In no other way can we transmit to posterity unimpaired the blessings of liberty, consecrated by the sacrifices of the Revolution.