This book aims to give a certain perspective on the subject of language rather than to assemble facts about it. It has little to say of the ultimate psychological basis of speech and gives only enough of the actual descriptive or historical facts of particular languages to illustrate principles. Its main purpose is to show what I conceive language to be, what is its variability in place and time, and what are its relations to other fundamental human interests-the problem of thought, the nature of the historical process, race, culture, art. The perspective thus gained will be useful, I hope, both to linguistic students and to the outside public that is half inclined to dismiss linguistic notions as the private pedantries of essentially idle minds. Knowledge of the wider relations of their science is essential to professional students of language if they are to be saved from a sterile and purely technical attitude. Among contemporary writers of influence on liberal thought Croce is one of the very few who have gained an understanding of the fundamental significance of language. He has pointed out its close relation to the problem of art. I am deeply indebted to him for this insight. Quite aside from their intrinsic interest, linguistic forms and historical processes have the greatest possible diagnostic value for the understanding of some of the more difficult and elusive problems in the psychology of thought and in the strange, cumulative drift in the life of the human spirit that we call history or progress or evolution. This value depends chiefly on the unconscious and unrationalized nature of linguistic structure. I have avoided most of the technical terms and all of the technical symbols of the linguistic academy. There is not a single diacritical mark in the book. Where possible, the discussion is based on English material. It was necessary, however, for the scheme of the book, which includes a consideration of the protean forms in which human thought has found expression, to quote some exotic instances. For these no apology seems necessary. Owing to limitations of space I have had to leave out many ideas or principles that I should have liked to touch upon. Other points have had to be barely hinted at in a sentence or flying phrase. Nevertheless, I trust that enough has here been brought together to serve as a stimulus for the more fundamental study of a neglected field.