Rhetoric (Gr. rhētorikē) in its broadest sense may be regarded as the theory and practice of eloquence, whether spoken or written. It aims at expounding the rules which should govern all prose composition or speech designed to influence the judgments or the feelings of men, and therefore treats of everything that relates to beauty or force of style, such as accuracy of expression, the structure of periods, and figures of speech. But in a narrower sense rhetoric concerns itself with a consideration of the fundamental principles according to which particular discourses of an oratorical kind are composed. The first to reduce oratory to a system were the Sicilian Greeks; its actual founder is said to have been Corax of Syracuse (c. 500 B.C.). He divided the speech into five parts, proem, narrative, arguments, subsidiary remarks, and peroration; and he laid great stress on the rhetorical capabilities of general probability. Later masters of rhetoric were Tisias; Gorgias of Leon-tini, whose style was burdened with too much ornament and antithesis; Antiphon, the earliest of the so-called 'Ten Attic Orators,' and the first writer of speeches for others to deliver in court. The speeches given by his great pupil Thucydides throughout his history, and the orations of Andocides, second of the Ten, are severely free from the florid ornament of later days. Lysias was an orator rather than a rhetorician; Isocrates first thoroughly taught rhetoric, which he defined as the 'science of persuasion,' as a technical method and discipline. His most celebrated pupils were Hyperides, Speusippus, and Isæus. The great Demostenes was a pupil of the last. His opponent Æschines, and his contemporaries Hyperides, Lycurgus, and Dinarchus complete the Ten. Anaximenes of Lampsacus composed the oldest extant manual of rhetoric, but the great classical work on this subject is the analytical masterpiece of Aristotle. According to him its function is not to persuade, but to discover the available means of persuasion in any subject. He regards it as the counterpart of logic, and arranges its uses as (1) the means by which truth and justice assert their superiority to falsehood and injustice; (2) the only method of persuasion suitable to popular audiences; (3) a means of seeing both sides of a case and of discerning the weakness of an adversary's argument; (4) as a means of self-defence. The means of persuasion he groups in two classes: (1) the inartificial proofs, such as statements of witnesses, contracts, and the like; (2) the artificial proofs, whether these are (a) logical, demonstration or seeming demonstration by argument; (b) ethical, when the speaker induces confidence by the weight of his own character; or (c) emotional, when he works persuasively on the feelings of his hearers.
Of these artificial proofs, first comes the logical, and this depends on the enthymeme, 'a syllogism from probabilities' and signs; next is the example. Of the materials of enthymemes, the topics or commonplaces of rhetoric, Aristotle distinguishes between the common, general heads applicable to all subjects as to their possibility or impossibility, and the special, those drawn from special arts or faculties.
He divides the three provinces of rhetoric thus: (1) Deliberative rhetoric, concerned with exhortation or dissuasion, and future time, its ends expediency and inexpediency; (2) Forensic rhetoric, concerned with accusation or defence, and with time past, its ends justice and injustice; (3) Epideictic rhetoric, concerned with eulogy or censure, and usually with time present, its ends being honour and disgrace, or nobleness and shamefulness. In his first two books Aristotle deals with invention, the discovery of means of persuasion; in the third, with expression and arrangement; and he begins the subject by discussing the art of declamation or delivery. Under verbal expressions he discusses the use of metaphor, simile, proverbs, rhythm, and variety of styles, as the literary and controversial, whether the political or the forensic.
Aristotle's method dominated the Peripatetic school, but later began to be modified by the florid influence of Asia, the originator of which was Hegesias of Magnesia. The school of Rhodes followed more closely Attic models, and gained great fame through its conspicuous leaders Apollonius and Molon (c. 100-50 B.C.). Hermagoras of Temnos (c. 120 B.C.) composed an elaborate system which long retained its influence. Later rhetoricians were Dionysius of Halicarnassus, Longinus, Hermogenes, Apsines, Menander, Theon, and Aphthonius. Among the earliest Roman orators were
Appius Claudius Cæcus (c. 300 B.C.), Cato the Censor, Ser. Sulpicius Galba, Caius Gracchus, Marcus Antonius, and Lucius Licinius Crassus. The instructors in formal rhetoric were Greek, and the great masters of theoretical and practical rhetoric alike, Cicero and Quintilian, were both formed by Greek models. The former contributed to a discussion of its theories no less than three treatises, De Oratore, the Brutus, and the Orator; the latter's famous Institutio Oratoria still retains its value. Quintilian strove hard to reform the taste of the time, which had become Asiatic through exclusive attention to the form and perpetual exercises in the schools on imaginary subjects—the suasoriae and controversiae of the elder Seneca. The Dialogus de Oratoribus, long ascribed to Tacitus, was another protest against modern fashion. The younger Pliny's Panegyric long remained a model for later orators. During the first four centuries of the empire rhetoric continued to be taught by 'sophists' at Athens, Smyrna, Rhodes, Tarsus, Antioch, Alexandria, and Massilia. These were in most esteem under Hadrian, the Antonines, and Marcus Aurelius—among the most celebrated were Theodotus, Polemon, and Adrian of Tyre. Throughout the middle ages rhetoric formed one of the subjects of the trivium; its leading authorities were Martinus Capella, Cassiodorus, and Isidorus. The subject re-awoke with the revival of learning, and was taught regularly in the universities, the prescribed public exercises and disputations keeping it long alive; but in later generations it has constantly languished, in spite of more or less laborious or effective attempts to fan it into life by the sententious Blair, the solid Campbell, and the sagacious Whately. In America, however, considerable attention is paid to it as a branch of general education.
See Aristotle's Rhetoric, with notes by E. M. Cope and J. E. Sandys (3 vols. 1877), the Introduction and Analysis by E. M. Cope (1867), and Translation by J. E. C. Weldon (1886); C. Ritter, Die Quintilianische Declamationen (1881); R. Volkmann, Die Rhetorik d. Griechen u. Römer (1872); Book iv. of St Augustine's treatise On Christian Doctrine; and J. Bascom's Philosophy of Rhetoric (New York, new ed. 1885). For the practical art of Rhetoric or Oratory, see M. Bautin, Art of Extempore Speaking (1858); the Abbé M. Delaunoy, Art of Oratory: system of Delsarte, trans. F. A. Shaw (Albany, 1882); Professor J. H. M'Ilvaine, Elocution: the Sources and Elements of its Power (1870); V. A. Pinkley, The Essentials of Elocution and Oratory (Cincinnati, 1888); C. J. Plumptre, Lectures on Elocution (1869); G. L. Raymond, The Orator's Manual: Vocal Culture, Emphasis, and Gesture (Chicago, 1879); and C. W. Bardeen, Rhetoric (New York, 1884).