_The Development of the New Science of International Law._ Out of the ruins of the old feudal system arose the modern state as a free independent unity. Private war between individuals or classes of society was now branded as a breach of the peace: it became the exclusive right of kings to appeal to force. War, wrote Gentilis[22] towards the end of sixteenth century, is the just or unjust conflict between states. Peace was now regarded as the normal condition of society. As a result of these great developments in which the name “state” acquired new meaning, jurisprudence freed itself from the trammelling conditions of mediæval Scholasticism. Men began to consider the problem of the rightfulness or wrongfulness of war, to question even the possibility of a war on rightful grounds. Out of theses new ideas—partly too as one of the fruits of the Reformation,[23]—arose the first consciously formulated principles of the science of international law, whose fuller, but not yet complete, development belongs to modern times. [22] It is uncertain in what year the _De Jure Belli_ of Gentilis was published—a work to which Grotius acknowledges considerable indebtedness. Whewell, in the preface to his translation of Grotius, gives the date 1598, but some writers suppose it to have been ten years earlier. [23] This came about in two ways. The Church of Rome discouraged the growth of national sentiment. At the Reformation the independence and unity of the different nations were for the first time recognised. That is to say, the Reformation laid the foundation for a science of international law. But, from another point of view, it not only made such a code of rules possible, it made it necessary. The effect of the Reformation was not to diminish the number of wars in which religious belief could play a part. Moreover, it displaced the Pope from his former position as arbiter in Europe without setting up any judicial tribunal in his stead. From the beginning of history every age, every people has something to show here, be it only a rudimentary sense of justice in their dealings with one another. We may instance the Amphictyonic League in Greece which, while it had a merely Hellenic basis and was mainly a religious survival, shows the germ of some attempt at arbitration between Greek states. Among the Romans we have the _jus feciale_[24] and the _jus gentium_, as distinguished from the civil law of Rome, and certain military regulations about the taking of booty in war. Ambassadors were held inviolate in both countries; the formal declaration of war was never omitted. Many Roman writers held the necessity of a just cause for war. But nowhere do these considerations form the subject matter of a special science. [24] Cf. Cicero: _De Officiis_, I. xi. “Belli quidem aequitas sanctissime feciali populi Romani jure perscripta est.” (See the reference to Lawrence’s comments on this subject, p. 9 above.)