As, however, Esperanto was found to contain a number of good principles, the Commission finally resolved to work out on purely scientific principles an international auxiliary language on the basis of Esperanto. The whole question of the introduction of an international auxiliary language has thus arrived at a stage in which it appears worthy of serious discussion. Under these circumstances, the writers of this brochure considered it their first duty to draw the attention of scientific and literary men to the matter, and so initiate discussion. The object of this book will have been attained, should they have succeeded in explaining the present state of the question, and in showing that it is already possible to discuss the introduction of an international auxiliary language into science, and indeed even seriously to make the attempt to carry it out. It may be remarked that the five authors of this book live in five different countries, and belong to three different languages. The very considerable correspondence required for the production of their book was carried out with the greatest success in the _Linguo Internaciona_, whenever any two of the correspondents possessed different mother-tongues. Paris, Copenhagen, Zürich, Gross-Bothen, Graz. L. COUTURAT, O. JESPERSEN, R. LORENZ, W. OSTWALD, L. PFAUNDLER. _March, 1909._ TRANSLATOR'S PREFACE The scientific attitude of mind is necessarily critical, but never sceptical without proper investigation and knowledge. The Translator hopes, therefore, that English-speaking men of science will not judge the question of international language before they have quietly and dispassionately examined the arguments so ably set forth in the following pages. It is not a question of "another language"; it is a question of the final solution by the methods of science of one of the greatest of scientific problems. Internationalisation of thought is the motto of the twentieth century, the device on the banner of progress. Science, the Super-Nation of the world, must lead the way in this as in all other things. Amidst the clangour and the clamour of political and commercial strife, the quiet empire of knowledge grows, noiseless and unseen. Let all those who believe that this peaceful empire is destined to become the controlling force of the world assist in the attunement of its common language. The Translator wishes to thank his friend and colleague, Professor J. P. Postgate, for having very kindly revised the translation of Chapters III. and IV. F. G. DONNAN. UNIVERSITY OF LIVERPOOL, _March, 1910_. TABLE OF CONTENTS PAGE Preface v CHAPTER I. The need for a common scientific language, by L. Pfaundler 1 II. The _Délégation pour l'adoption d'une langue auxiliaire internationale_, by R. Lorenz 11