A figure of speech or rhetorical figure is figurative language in the form of a single word or phrase. It can be a special repetition, arrangement or omission of words with literal meaning, or a phrase with a specialized meaning not based on the literal meaning of the words. Figures of speech often provide emphasis, freshness of expression, or clarity. However, clarity may also suffer from their use, as any figure of speech introduces an ambiguity between literal and figurative interpretation.
Classical rhetoricians classified figures of speech into four categories or quadripartita ratio:
These categories are often still used. The earliest known text listing them, though not explicitly as a system, is the Rhetorica ad Herennium, of unknown authorship, where they are called πλεονασμός (addition), ἔνδεια (omission), μετάθεσις (transposition) and ἐναλλαγή (permutation). Quintillian then mentioned them in Institutio Oratoria.Philo of Alexandria also listed them as addition (πρόσθεσις), subtraction (ἀφαίρεσις), transposition (μετάθεσις), and transmutation (ἀλλοίωσις).
Figures of speech come in many varieties. The aim is to use the language inventively to accentuate the effect of what is being said. A few examples follow:
Scholars of classical Western rhetoric have divided figures of speech into two main categories: schemes and tropes. Schemes (from the Greek schēma, form or shape) are figures of speech that change the ordinary or expected pattern of words. For example, the phrase, "John, my best friend" uses the scheme known as apposition. Tropes (from the Greek trepein, to turn) change the general meaning of words. An example of a trope is irony, which is the use of words to convey the opposite of their usual meaning ("For Brutus is an honorable man; / So are they all, all honorable men").
During the Renaissance, scholars meticulously enumerated and classified figures of speech. Henry Peacham, for example, in his The Garden of Eloquence (1577), enumerated 184 different figures of speech. Professor Robert DiYanni, in his book "Literature – Reading Fiction, Poetry, Drama and the Essay" wrote: "Rhetoricians have catalogued more than 250 different figures of speech, expressions or ways of using words in a nonliteral sense.".