HEADQUARTERS OF THE ARMY,
Washington, August 6, 1862.

Dr. FRANCIS LIEBER,

New York:

MY DEAR DOCTOR: Having heard that you have given much attention to the usages and customs of war as practiced in the present age, and especially to the matter of guerrilla war, I hope you may find it convenient to give to the pubic your views on that subject. The rebel authorities claim the right to send men, in the garb of peaceful citizens, to waylay and attack our troops, to burn bridges and houses, and to desd persons within our lines. Hey demand that such persons be treated as ordinary belligerent, and that when captured they have extended to them the same rights as other prisoners of war; they also threaten that if such persons be punished as marauders and spies they will retaliate by executing our prisoners of war in their possession. I particularly request your views on these questions.

Very respectfully, your obedient servant,

H. W. HALLECK,

General-in-Chief U. S. Army.

[Doctor Lieber's reply.]

Guerrilla parties considered with reference to the laws and usages of war.

The position of armed parties loosely attached to the main body of the army, or altogether unconnected with it, has rarely been taken up by writers on the law of war. The term guerrilla is often inaccurately used, and its application has been particularly confused at the present time. From these circumstances arises much of the difficulty which presents itself to the publicist and martial jurist in treating of guerrilla parties. The subject is substantially a new topic in the law of war, and it is, besides, exposed t the mischievous process, so often employed in our day, of throwing the mantle of a novel term around an old and well-known offense, in the expectation that a legalizing effect will result from the adoption of a new word having a technical sound; and illustration of which occurred in the introduction of the Latin and rarer term repudiation to designate the old practice of dishonestly declining the payment of debts-an offense with which the world has been acquainted ever since men united in the bonds of society. We find that self- constituted bands in the South, who destroy the cotton stored by their own neighbors, are styled in the journals of the North as well as in those of the South guerrillas; while in truth they are, according to the common law-not of war only, but that of every society-simply armed robbers, against whom every person is permitted, or is in duty bound, to use all the means of defense at his disposal; as, in a late instance, even General Toombs, of Georgia, declared to a certain committee of safety of his State that he would defend the planting and producing of his cotton; though, I must own, he did not call the self-constituted committee guerrillas, but, is memory serves me right, scoundrels.

The term guerrilla is the diminutive of the Spanish word guerre, war, and means petty war; that is, war carried on by detached parties, generally in the mountains. It means, further, the party of men united under one chief engaged in petty war, which, in the eastern portion of Europe and the whole Levant is called a capitanery, a