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.

I desire to express my cordial appreciation of the friendly advice and
helpful suggestions of a number of friends who have read the work in
manuscript, notably Profs. A.L. Kroeber and R.H. Lowie of the University
of California, Prof. W.D. Wallis of Reed College, and Prof. J. Zeitlin