The name Charles Sanders Peirce is associated with the science of signs called semiotics, which studies the sign as the carrier of meaning that is placed in the center of his work. Peirce developed a system of concepts that describe how the sign as such is understood by the mind. For the conditions of its interpretations Peirce established various so-called interpretants for the explanation of signs associated with the utterer and interpreter and a shared process that enables the communication between (...) communicators. Further to the renovation of the theory of rhetoric and communication, we show that medium and communication must be understood within the framework of his theory in association to the sign and the object. Throughout his manuscripts the triads of his concepts are realized in the text in rhetorical tricola as terms of his philosophy. In comparison to Aristotle’s Rhetoric, which employed the sign as a means for reasoning, we will show how Peirce developed techniques of reasoning based on Aristotle’s work and his model of mental understanding of the sign while foreshadowing a theory of communication that aims at describing the exchange of information in a model. (shrink)