Peace is the normal condition of a country, and war abnormal, neither being without law, but each having laws appropriate to the condition of society. The maxim _enter arma silent leges_ is never wholly true. The object of war is to bring society out of its abnormal condition; and the laws of war aim to have that done with the least possible injury to persons and property. Anciently, when two nations were at war the conqueror had, or asserted, the right to take from his enemy his life, liberty, and property: if either was spared it was a favor, or act of mercy. By the laws of nations, and of war as a part thereof, the conqueror was deprived of this right. When two governments, foreign to each other, are at war, or when a civil war becomes territorial, all of the people of the respective belligerents become by the law of nations the enemies of each other. As enemies they cannot hold intercourse, but neither can kill or injure the other except under a commission from their respective governments. So humanizing have been, and are, the laws of war, that it is a high offense against them to kill an enemy without such commission. The laws of war demand that a man shall not take human life except under a license from his government; and under the Constitution of the United States no license can be given by any department of the government to take human life in war, except according to the law and usages of war. Soldiers regularly in the service have the license of the government to deprive men, the active enemies of their government, of their liberty and lives: their commission so to act is as perfect and as legal as that of a judge to adjudicate; but the soldier must act in obedience to the laws of war, as the judge must in obedience to the civil law. A civil judge must try criminals in the mode prescribed in the Constitution and the law; so, soldiers must kill or capture according to the laws of war. Non-combatants are not to be disturbed or interfered with by the armies of either party except in extreme cases.