Europe in the last two thousand years has three times passed through an experience which may fairly be called a Thirty Years War; in Greece from 432 to 404 B.C., in Central Europe from A.D. 1618 to 1648; and over the whole continent from 1914 to 1945; in all of them there were intervals in which the fighting ceased, but the interval hardly amounted to true peace; it was more like what a certain scholiast calls it, ἐχεχειρία ὕπουλος, ώδίνουσα, πόλεμον. In all three cases one notices a certain rhythm; an increase of brutality and demoralisation persisting to the end of the war and after, and later on a sort of revulsion of thought, an attempt to make sure that such evils shall not happen again. In our time it is the League of Nations movement; after the Thirty Years War it is the effort to distinguish between just and unjust wars, and establish international law, which centres in Grotius' De Jure Pacis et Belli. After the Peloponnesian War it is the magnificent conception of World Citizenship made specially articulate in Zeno's ideal Republic.

In the present paper I have tried to analyse a little more closely the actual reactions of Greek thought and practice to the first of these long strains of embittered war.