The art of speaking or writing effectively: as a.) the stuy of principles and rules of composition formulated by critics of ancient times, and b.) the study of writing or speaking as a means of communication or persuasion. In Greece, rhetoric originated in a school of pre-Socratic philosophers known as Sophists c.600 BC. It was later taught, in the Roman Empire, and during the Middle Ages, as one of the three original liberal arts or trivium (along with logic and grammar).