Discussion will take place, with more and more vigour as years go on, as to the various measures which have been described collectively as the establishment of a World-State. At what point could it be said that a World-State is in being? How can such a World-State be reconciled with the independent sovereignty of the several States comprised in it? What is to be the sanction imposing the decisions of the larger community on its constituent members? Such are a few of the problems involved in any advance towards the Kantian ideal of cosmopolitanism. None of them admit of a single definite answer. They do not belong to questions of pure theory, and we shall have to solve them slowly and with difficulty, seizing every favourable opportunity of a slight advance, avoiding grave obstacles, compromising with every possible friend. But for the moment we seem likely to be overwhelmed by unchained passions which are the practical denial of everything that the ideal of humanity implies. Instead of co-operation we are faced by schemes of conquest and domination, and the simplest notion of brotherhood is limited to comradeship in arms for defence or attack. Many will be found to ridicule the idea that any real progress in unity has ever been made, or that the world can ever be envisaged except as an irksome enclosure of rival armed forces thirsting for the fray. But to those who are not prepared to accept this as the last word in human association the argument of this volume may have some weight. It will lead those who follow it to a quiet but well-grounded belief that the forces tending to unity in the world are different in quality, incomparably greater in scope than those which make for disruption. Discord is explosive and temporary, harmony rises slowly but dominates the final chord.