This book is a gem of knowledge and analysis. I believe it to be the best book on linguistics and natural language ever written. The writing is clear, the arguments concise and cogent. I believe the book has stood the tests of time intact.The essential strength of the logic and analytic treatment of language remain exceptionally powerful. The book should have caused a revolution in the field when it was first published. Instead, it has been under appreciated by the mainstream, especially the adherents of the Choamsky view of language, which I believe, has been to their detriment. The book will be useful to those enaged in developmental psychology, and philosophy, as well as those interested in language and linguistics. I highly recommend this book.