The original meaning of the word rhetoric - the science of oratory - later expanded to the theory of prose, argumentation. Rhetoric developed under the influence of Aristotle, Cicero and Quintilian. Aristotle's Rhetoric is a work that views public speaking as an essential tool for social interaction and government. Aristotle interprets speech as a way of resolving contradictions, reaching agreements and changing public opinion. The treatise has not lost its relevance today. It may well and even should be studied by those who need the art of persuasion, the selection of arguments, the science of communication and methods of clearly expressing their thoughts in life. Aristotle is the greatest of the philosophers of the ancient world, whose authority was unshakable in the Middle Ages, when the church rejected all the heritage of ancient Greece as pagan, and whose works remained in demand in modern times.