ional ruin, and yet may even require
revolutions for their reformation; but any one of the laws of nations
preserves its vitality, only with the essential truth of its
principles; a change in the feeling of mankind on the great question
of real justice, destroys it, and it simply remains an historical
record of departed opinion, or a point from which to date an advance
or retreat in the career of the human mind.

It is for this reason that International Law has been so differently
defined by writers at various periods.

The Law of Nations is _founded_, I have said, on the general
principles of right and justice, on the broad fundamental distinctions
between right and wrong, or as Montesquieu defines it, "on the
principle that nations ought in time of peace to do each as much good,
and in time of war as little harm as possible." These are the
principles from which any rule must be shown to spring, before it can
be said to be a rule for international guidance. But what are the
principles of right and wrong? These are not left to the individual
reason of the interpreter of the law for the time being, but are to be
decided by the _public opinion of the civilized world_, as it stands
at the time when the case arises.

It may immediately be asked--How is that public opinion to be
ascertained? The answer is--By ascertaining the _differences_ in
opinion between the present and the past. For this purpose it must be
observed, that the views of a past age are easily ascertainable, in
matters of law, from theoretical writings, history, and judicial
decisions; and these views may be reduced to definition. Modern
universal intelligence will either agree or disagree in these views.
In the mass of instances it will agree, as progress on such points is
at all times slow; and not only will the points of _disagreement_ be
few, but they will be salient, striking, and generally of popular
notoriety. Present, universal, or international opinion, has therefore
two portions. 1. That in which it accords with the views of a past
generation, that has become historical. 2. That in which it differs
from, or contradicts those views.

In the first instance, then, we are to ascertain what _were_ the
principles of right and justice, from any materials handed down to us;
and if those principles agree with, or support the practical rules
recorded by the same, or similar sources of information, such are to
be accepted as belonging to the code of the