Within the framework of communication studies, there exist, as is known, several theoretical approaches, each claiming to be the dominant one. What then secures for communication studies the status of a unified scientific discipline? On analyzing the constituting principles of competitive trends in communication studies, the author comes to the conclusion that the disciplinary unity is not provided by the research subject (each school has its own research subject), but by the common basic set of problems, and getting beyond the limits of latter turns a scientific trend into a marginal one. This basic set of problems applies to the research of mass communication as a power resource. According to the author's conclusion, the polythematic character of communication studies is preconditioned first of all by principled metaphysical and axiological distinctions in comprehension of power, which exactly turns political science into that very metatheory, with the help of which it is possible to account for the internal gaps and contradictions inherent in the discipline in question.