In trying to give an account of the statistical properties of language, one is faced with the problem of having to find the common thread which would show the many and multifarious forms of language statistic- embodied in scattered papers written by linguists, philosophers, mathe maticians, engineers, each using his own professional idiom - as belong ing to one great whole: quantitative linguistics. This means that the investigator has to find the system of this branch of science which would enable him to arrange the vast material in an orderly fashion, and present it as an organic whole. Such a system is conceived in this book, as comprising the following disciplines as the four main branches of literary statistics: Statistical Linguistics, Stylostatistics, Optimal Systems of Language Structure, and Linguistic Duality (Parts I-IV). The Introduction is meant to define the position of the book with regard to both, linguistics and statistics.