APPENDIX TO PART FIPvST. 21 



We observettiat notafew of these customs have, in course of timebeen 

 abolished, and that in some cases directly opposite customs have been 

 introduced. 



In vain has a certain writer impugned our opinion as if it were sub- 

 versive of the foundations of the safety, advantage, and welfare of na- 

 tions; for all that is not dependent upon the customs just referred to, 

 but upon the observance of the natural law, which is a much more solid 

 principle and one deserving of much greater respect. If its rules are 

 carefully observed, mankind will not have much need of these customs. 

 Moreover, by basing a custom upon the maxims of natural law, a much 

 more noble origin is given it, and also much greater authority than if 

 it were made to depend upon a mere agreement among nations. 



[Ortolan. International Rules and Diplomacy of the Sea. Paris, 1864, vol. I, book 

 I, ch. iv., page 71. Translation.] 



It is apparent that nations not having any common legislator over 

 them have frequently no other recourse for determining their respective 

 rights but to that reasonable sentiment of right and wrong, but to 

 those moral truths already brought to light and to those which are still 

 to be demonstrated. This is what is meant when it is said that natural 

 law is the first basis of international law. This is why it is important 

 that Governments, diplomats, and publicists that act, negotiate, or 

 write upon such matters should have deeply (rooted) in themselves this 

 sentiment of right and of wrong which we have just defined, as well as 

 the knowledge of the point of certainty (point de certitude) where the 

 human mind has been able to attain this order of truths. 



But nations are not reduced only to that light, too often uncertain 

 of human reason, for defining their reciprocal rights. Experience, 

 imitation of accomplished precedents, and long practical usage habit- 

 ually and generally observed add to it what is termed a custom which 

 forms the rule of international conduct and from which flows on one or 

 the other side positive rights (adroits). The binding force of custom 

 is founded on consent, the tacit agreement, of nations. Nations have 

 thus tacitly agreed among themselves, and they have bound them- 

 selves through this tacit agreement, for the reason that they have 

 practiced it so long and so generally. 



The supremacy of custom is much more frequently exercised and 

 much more extensive in international law than in private law; pre- 

 cisely because in international law there is no common legislator to 

 restrain such supremacy by formulating the rule of conduct in writ- 

 ing. Custom is often comformable to the light of reason upon that 

 which is right or wrong because it emanates from communities or col- 

 lections of reasonable beings; but frequently also it is contrary to it, 

 because the reason of man, individual or collective, is subject to error; 

 finally, it tends more and more intimately to approach it, because the 

 path of man, an essentially perfectible being, is a path of improvement 

 and progress. 



It must be stated that treaties, far from justifying the exclusion of 

 moral truths of what is right or wrong, among nations, which one 

 wishes to deduce from them, precisely only obtain their binding force 

 but from one or the other of those truths. It is because the natural 

 sentiment of right dictates to all that a regular agreement of inde- 

 pendent wills between qualified persons on allowable subjects and cases 

 binds the contracting parties to each other, it is therefore that treaties 



