Therefore, Sir, in determining our course, we may banish all question of power. The power is ample and indubitable, being regulated in the one case by the Constitution, and in the other case by the Rights of War. Treating them as criminals, then are we under the restraints of the Constitution; treating them as enemies, we have all the latitude sanctioned by the Rights of War; treating them as both, then may we combine our penalties from the double source. What is done against them merely as _criminals_ will naturally be in conformity with the Constitution; but what is done against them as _enemies_ will have no limitation except the Rights of War. The difference between these two systems, represented by two opposite propositions now pending, may be seen in the motive which is the starting-point of each. Treating those arrayed in arms against us as criminals, we assume sovereignty, and seek to punish for violation of existing law. Treating them as enemies, we assume no sovereignty, but simply employ the means known to war in overcoming an enemy, and in obtaining security against him. In the one case our cause is founded in Municipal Law under the Constitution, and in the other case in the Rights of War under International Law. In the one case our object is simply punishment; in the other case it is assured victory. * * * * * Having determined the existence of these two sources of power, we are next led to consider the character and extent of each under the National Government: first, _Rights against Criminals_, founded on sovereignty, with their limitations under the Constitution; and, secondly, _Rights against Enemies_, founded on war, which are absolutely without constitutional limitation. Having passed these in review, the way will then be open to consider which class of rights Congress shall exercise. I. I begin, of course, with _Rights against Criminals_, founded on sovereignty, with their limitations under the Constitution. Rebellion is in itself the crime of treason, which is usually called the greatest crime known to the law, containing all other crimes, as the greater contains the less. But neither the magnitude of the crime nor the detestation it inspires can properly move us from duty to the Constitution. Howsoever important it may be to punish rebels, this must not be done at the expense of the Constitution. On that point I agree with the Senator from Pennsylvania [Mr. COWAN], and the Senator from Vermont [Mr. COLLAMER]; nor will I yield to either in determination to uphold the Constitution, which is the shield of the citizen. Show me that any proposition is without support in the Constitution, or that it offends against any constitutional safeguard, and it cannot receive my vote. Sir, I shall not allow Senators to be more careful on this head than myself. They shall not have a monopoly of this proper caution.