Changes already wrought in the Laws of War teach that the whole System may be abolished. The existence of laws implies authority that sanctions or enacts, which, in the present case, is the Commonwealth of Nations. This authority can, of course, modify or abrogate what it originally sanctioned or enacted. In the exercise of this power, the Laws of War have been modified, from time to time, in important particulars. Prisoners taken in battle cannot now be killed; nor can they be reduced to slavery. Poison and assassination can no longer be employed against an enemy. Private property on land cannot be seized. Persons occupied on land exclusively with the arts of Peace cannot be molested. It remains that the authority by which the Laws of War have been thus modified should entirely abrogate them. Their existence is a disgrace to civilization; for it implies the _common consent_ of nations to the Arbitrament of War, as regulated by these laws. Like the Laws of the Duel, they should yield to some arbitrament of reason. If the former, once so firmly imbedded in Municipal Law, could be abolished by individual nations, so also can the Laws of War, which are a part of International Law, be abolished by the Commonwealth of Nations. In the light of reason and religion there can be but one Law of War,--the great law which pronounces it unwise, unchristian, and unjust, and forbids it forever, as a crime. Thus distinctly alleging the practicability of our aims, I may properly introduce an incontrovertible authority. Listen to the words of an American statesman, whose long life was spent, at home or abroad, in the service of his country, and whose undoubted familiarity with the Law of Nations was never surpassed,--John Quincy Adams. "War," he says, in one of the legacies of his venerable experience, "by the common consent and mere will of civilized man, has not only been divested of its most atrocious cruelties, but for multitudes, growing multitudes of individuals, has already been and is abolished. _Why should it not be abolished for all?_ Let it be impressed upon the heart of every one of you, impress it upon the minds of your children, _that this total abolition of War upon earth_ is an improvement in the condition of man entirely dependent on his own will. He cannot repeal or change the laws of physical Nature. He cannot redeem himself from the ills that flesh is heir to. But the ills of War and Slavery are all of his own creation; he has but to will, and he effects the cessation of them altogether."[361] [361] Oration at Newburyport, July 4, 1837, pp. 56, 57.