By a similar train of reasoning, not only may the international tribunals of England enunciate new rules of law, as universal law, if founded and fairly deduced from ascertained modern, public, and international opinion; but they may refuse to alter settled rules, however much opposed by other nations, provided those rules are still deducible from that origin.

Generally, every doctrine fairly deduced, by correct reasoning, from the rights and duties of nations, and the nature of moral obligation, may be said to exist in the Law of Nations.  Those rights, duties, and that moral obligation, are to be ascertained from the enunciation of them in past times, unless they have been relaxed, waived, or altered by universal modern opinion.

We may regard, then, the Law of Nations to be a system of political ethics; not reduced to a written code, but to be sought for, (not founded,) in the elementary writings of publicists, judicial precedents, and general usage and practice; but continually open to change and improvement; as the views of men in general, change or improve, with regard to the questions—­What is right?  What is just?

Now to apply the above to one example.

Undoubtedly up to the present time the system of granting Letters of Marque to the adventurers of a power friendly to the enemy, has received the sanction of the world.  These buccaneering adventurers have, under the laws of war, when taken, claimed and been allowed the rights of prisoners of war; have exercised all the privileges of regular privateers, and cast little or no responsibility on the countries they issued from, who still claimed to be entitled to the full position of neutral powers.  Yet these unprincipled men differed from pirates in one respect only—­that their infamous warfare was waged on one unhappy nation alone, instead of against the power of mankind.  Uninfluenced by national feelings, their sole object was the plunder of the honest trader, and the means to that end—­murder.  Are there any modern principles of right and justice by which such persons are still to claim consideration?  That there were such principles formerly, when the whole system of war was barbaric and unmerciful, cannot be doubted, unless such enemies were to be condemned when others equally bad were to be excused; but those reasons have now disappeared.  Universal opinion is against these principles; numerous treaties have condemned the practice; the municipal laws of several states have made it punishable in their own subjects; America has even attempted, in two cases, to bring it in as piracy; and the highest authorities have pronounced it a crime.

Are not then the foundations of the laws that governed this case changed?  It may be going too far to declare it piracy by the Law of Nations, but is it asking too much, in calling upon our maritime tribunals to proclaim the practice contrary to the Law of Nations; to deprive these privateers of the protection of neutrality, when in their native waters, and to subject the nation that permits them to fit out in, or issue from their ports, to the danger of reprisals, from the offended belligerents.