The paper points out that the earliest theoretical concepts of communication originated from rhetorical teachings in ancient Greece and Rome, and then can be found in medieval Christian, patristic and scholastic exegesis. Speech and conversation, as rhetorical topics, were in the center of attention of Greek philosophers of the classical period, and later in Rome, and the doubt whether a good speaker speaks the truth or speaks well is still not only a rhetorical, but also a stimulating communication problem. The chroniclers of communication research notice that the intellectual-content direction in ancient rhetoric has exerted the influence on European communicologists, similar to the one that rhetoricalformalistic direction exerts on the mainstream of American communication researchers. In the Middle Ages, Christianity and rhetoric became inseparable in preaching and prayer, and the focus of the mentioned dilemma was shifted from the field of ethics and logic to the sphere of dogma. In theological works, a whole series of prayer and preaching rules has been developed for intrapersonal communication with metaphysical beings, interpersonal communication of believers and communication of priests with the audience of believers. The paper concludes that there are few theories of communication in modern times that, at least indirectly, do not take into account rhetorical postulates created in ancient and medieval times, the "prehistoric" period of modern interdisciplinary research and reflection on human communication.