The object of this book is to make clear, by the use of a minimum number of examples, generally taken from French, that science encounters in languages phenomena which are organized according to structure. These phenomena function as tools of communication among men in a society at a given place and time, and as subjects in the evolution that constantly carries them forward. This work is written so that the reader may note the application of general principles brought out by the method of materialistic dialectics. The introduction and conclusions of the chapters (Language Development, Language Structure, Language Evolution) underline this general point of view: Because linguistics reflects factual dialectics, when it is correctly practiced it cannot help but itself be a dialectic. Still a very young science, it cannot progress until certain advances have been made in other branches of the social sciences, especially in psychology, by using the same dialectic materialistic method. The need to relate, in the future, linguistic problems to other social problems has been stated and restated as a necessary avenue to future research. (The French version of this work, published in 1950, has been out of print since 1955. This first translation into English has incorporated some bibliographical revision by the author.) (Author/AMM)