C. tries to develop a unified science of language and logic, which can be considered 'pragmatic'. The book contains chapters on information and language, on the principles of describing language, on language and deductive logic, and language and inductive logic, on semantics, axiomatics, and meaning (all being methodological and foundational), a chapter providing a case study of logico-linguistic analysis, viz. of the usage of 'if - then', and finally a chapter on the problem areas of the theory, and on computer applications.