Concepts of general systems theory, cybernetics and the like may provide the methodology for communication theory to move from a level of technology to a level of pure science. It was the purpose of this paper to (1) demonstrate the necessity of applying systems theory to the construction of communication theory, (2) review relevant systems concepts and principles, and (3) specify the applicability of systems theory to communication theory development and specific methodological proposals. In part 1 the continuous nature of communicative phenomena is examined with particular attention being given to the notion of the mathematical function. Part 2 begins at a very basic systems level, i.e. the notion of wholes as compared with aggregates and relations. It continues with a discussion of open systems principles such as: equifinality, dynamic homeostatasis or the steady state, entrophy and ectrophy and Prigogine's equation. The concluding section considers the cybernetic notion of deviation amplifying mutual causation and the role of simulation in the construction of communication theory. (Author/LG)