In a previous paper the attempt was made to state Vattel's system of municipal and international jurisprudence, and to show in a general way the authority attributed to his treatise on international law. It remains for us to consider the technical rules of international law proposed by Vattel and thus to lay the basis for a critical estimate of the position to which his treatise is entitled among the classics of international law.

The rules of conduct which nations have voluntarily adopted for themselves, and which therefore constitute the law between them, may be divided, with regard to their intrinsic character, into two general classes: first, rules which define certain principles of moral conduct or which embody the recognition of certain fundamental rights of states, and secondly, rules which define the concrete application of principles to the practical relations of states. Chief of the rules defining principles of moral conduct is the rule of good faith between nations, which in its many applications pervades the whole field of international law. This rule of good faith is not merely an a priori conception deduced from the analogy between sovereign states as members of an international community and private persons as members of society; it is a rule of positive international law, accepted by nations as properly controlling their conduct, and appealed to by them in their diplomatic relations.