Rhetoric and dialectic are closely related theories of (and trainings in) persuasion. They have some distinct bodies of doctrine (e.g., the topics of invention and the enthymeme belong to dialectic; the theory of disposition and the figures of speech to rhetoric) but over time they have also overlapped and annexed each other’s territory. Theorists today attempt to incorporate the insights and teachings of both subjects into an overarching theory of persuasive communication. These attempts have some instructive historical antecedents which will be the main subject of this article.
Dialectic In Greek And Roman Rhetoric
To understand the history of the relations between rhetoric and dialectic it is necessary to take account of changes in the definition of dialectic and in the educational context of the two subjects. For Plato dialectic meant the training in philosophy acquired through dialogue and argument. For Aristotle dialectic is the technique of argument used in everyday conversations and in subjects (such as politics or questions of practical behavior) where certain reasoning, which he called analytic, was not possible. Later in antiquity and in the Middle Ages and Renaissance, “dialectic” and “logic” were synonyms, so dialectic included both plausible and certain reason, both the topics and the syllogism. Since the nineteenth century the term “dialectic” has generally been used to refer to the logical method of Hegel and of Marxism. This is connected to the classical Greek idea of dialectic, but is separate from the mainly Latin tradition with which this article is concerned.
Aristotle says that rhetoric and dialectic are counterparts because they are both concerned with questions that cannot be resolved scientifically. Dialectic treats such questions more generally, while rhetoric is concerned with persuasion in the three contexts in which speeches were made in Athens: the law court, the public assembly, and the occasion for celebration or blame. Aristotle was the first to admit the teaching of rhetoric into the school of philosophy and the first to give a systematic account of all the doctrines of rhetoric. Throughout the Hellenistic world the rhetoric schools were the dominant form of higher education.
When Cicero argued in De oratore that orators needed a knowledge of dialectic, for which he wrote his textbook Topica and whose doctrines he incorporated in his late synthesis, Partitiones oratoriae, he was campaigning for a broadening of rhetorical education. For Quintilian dialectic, including the syllogism, the topics, and the four Stoic forms of inference, were part of the orator’s education. For much of late antiquity and the early Middle Ages it was usual to study rhetoric and dialectic together as constituent parts of the cycle of seven liberal arts. Later in the medieval period the study of logic came to dominate the whole arts course of the universities which were founded then, with rhetoric relegated to the sidelines. In fourteenth-century Italy some teachers of letter-writing, a subject at the margins of the university arts course, revived the imitation of classical Latin and took a more literary approach to the study of Latin rhetoric.
Dialectic In European Renaissance
Lorenzo Valla was appalled by what he saw as the pointless intricacy of late scholastic logic and by logic’s domination of the university arts course. His Repastinatio dialecticae et philosophiae (1439) is a wide-ranging attack on Aristotelian philosophy. He insists on the wide range of talents and skills required for rhetoric, but argues that this demanding skill need be mastered only by the few people who will become leaders. By contrast dialectic is much simpler, consisting of a small part of one of rhetoric’s five skills. For him dialectic is concerned with practical arguing in good Latin. It involves the study of topical invention, careful attention to the implications of words employed, and the presentation of arguments in a small number of forms of argumentation, which need not be stated in full.
Compared with the years required to gain a thorough knowledge of Greek and Latin grammar, dialectic, which everyone needs to study, should take only a few weeks. Valla’s polemical work sets out the goal of a simple and accessible dialectic expressed in classical Latin but this goal was most nearly achieved by his enemy, George of Trebizond, whose Isagoge dialectica (late 1430s) gives an introduction to Aristotelian logic, including the elements Valla rejected, expressed in classical Latin. Unlike Valla’s work, it was a viable teaching book and achieved considerable success with around 60 editions in the fifteenth and sixteenth centuries.
Rudolph Agricola’s De inventione dialectica (1479) treats dialectical invention as the key element in the composition of texts of many different kinds. Agricola rewrites the topics of invention (for example, definition, genus, cause, and contrary) so as to put more emphasis on the nature of the argumentative relationship defined, on its use in practical arguing, and on the method of producing arguments of each type. Familiarity with the topics of invention enables a writer to find whatever can usefully be said on a topic. The best arguments found must be selected and expressed either as simple expositions or as fully supported and elaborated argumentations. He regards the distinction between exposition and argument as partly a matter of audience (it is exposition when you state something simply to an audience that follows; argumentation when an audience resists and you pile in additional reasons and extort their assent) and texture (exposition is plain; argumentation involves density of reasoning and figures).
Furthermore he argues that emotional persuasion is subject to logical processes (for example, to make someone feel pity for a person you must show them that their fate is both harsh and undeserved). Rather than fitting all works into the traditional rhetorical model of the four-part oration, Agricola argues that many different models are available for the structure of texts and that the writer must think about the appropriate form by reflecting on the arguments he or she has assembled, the nature and attitude of the audience (which will enable him or her to work out the key question to be addressed) and what he or she wants to achieve. One of Agricola’s suggestions for practical training in becoming familiar with topics, argumentation, and exposition was the dialectical analysis of a text, for example a speech from Virgil’s Aeneid or by Cicero. Agricola’s dialectical commentary on Cicero’s speech Pro lege Manilia became the model for the numerous dialectical commentaries written by Latomus, Melanchthon, and Ramus.
In effect Agricola’s work proclaimed the new technique of dialectical invention to be the core of the composition of literary, technical, and persuasive works. He presented the moods and figures of the syllogism and the figures of rhetoric, which were easily available in other texts, as necessary add-ons to complete the training in arguing and composition. Although Agricola enjoyed a great reputation in northern Europe, with many publications of his work, his unification of rhetoric and dialectic around dialectical invention ran against the disciplinary boundaries of schools and universities so that teachers took different views on where it should fit within the syllabus. Erasmus combined techniques from both subjects under the umbrella of variation and rhetorical amplification of an existing text in his highly successful De copia (1512). The first book, on copia of words, suggests methods of varying or extending the language of a phrase on the basis of figures of grammar and rhetoric, while the second, on copia of things, uses the topics of invention to discover more material within, or to vary the presentation of, something already expressed.
Philipp Melanchthon was called to Wittenberg at the age of 21 to teach Greek and rhetoric. His De rhetorica libri tres (1519) emphasizes the close relationship between rhetoric and dialectic. In his (Aristotelian) view all subjects depend on dialectic, yet dialectic itself became deprived and useless when (presumably in the medieval universities) rhetoric was removed from the schools. He proclaims the common purpose of dialectic and rhetoric, the former restrained and suited to teaching, the latter spreading itself more fully and ready to move an audience.
This book included much of the syllabus of dialectic within the invention section of a rhetoric textbook. But since his audience asked him for even more dialectic, he first produced a short overview of the whole of dialectic, Compendiaria dialectices ratio (1520), and then, to complement it, a rhetoric without so much dialectic, Institutiones rhetoricae (1521). Melanchthon’s first attempt at a comprehensive rhetoric which included the dialectical material that he thought necessary was thus replaced by separate textbooks for the two subjects, including the now traditional areas of overlap, which he later expanded further.
Peter Ramus adopted a different approach to the problem of combining rhetoric and dialectic (Dialecticae libri duo, 1556). He always expected that rhetoric and dialectic would be taught together and that the theoretical training offered by manuals of the two subjects would be complemented by readings in classical literature and oratory, which would demonstrate the way in which effective persuasive writing combines the skills taught by both. His theory of method obliged him to start at a very general level, proceeding by division to specifics and to avoid all overlaps between subjects.
This encouraged him to declare that dialectic was composed of only two elements, invention and judgment. Invention described the topics, while judgment was sub-divided into the theory of the proposition, the syllogism, and method. By the same simplification, rhetoric comprised only style, that is to say, the tropes and figures, and delivery. Thus while Ramus certainly oversimplified both subjects (partly in the hope that, contrary to frequent practice, the whole of each subject would be covered in class), the claim that he taught a rhetoric without invention needs to be qualified by the observation that he expected his pupils to learn invention within the dialectic studies which they pursued alongside rhetoric. The textbooks of Ramus and Melanchthon enjoyed enormous success throughout northern Europe, without replacing the classical textbooks (for dialectic, Aristotle; for rhetoric, Rhetorica ad Herennium, Cicero, and Quintilian) required by the university syllabus.
Seventeenth Century To Today
In the seventeenth and eighteenth centuries the tendency was for rhetoric and dialectic to be presented separately, with more attention to the emotions in rhetoric manuals as a result of a gradually increasing domestication of Aristotle’s Rhetoric. George Campbell’s Philosophy of rhetoric (1776) adapted and absorbed much of the teaching associated with topical invention and syllogistic as part of the foundations of eloquence before going on to discuss purity of language and qualities of style. Where Hugh Blair’s Lectures on rhetoric and belles lettres (1783) focus on language, taste, style, and criticism, and Alexander Bain’s English composition and rhetoric (1887) was devoted to the English sentence, paragraphing, figures of speech (organized logically), and intellectual and emotional qualities of style, Richard Whately’s Elements of rhetoric (1846) included a good deal of dialectic in its discussion of the types of argument and methods of presentation, even though Whately composed a parallel Elements of logic (1827), and the two textbooks were often taught together, for example in North American colleges. The nineteenth century saw a gradual decline in the teaching of Aristotelian logic and its replacement with the more mathematical formal logic.
Reactions against the abstractness and lack of application of formal logic have caused some philosophers to attempt to formulate rules for practical arguing. Stephen Toulmin’s The uses of argument (1958), for example, develops a theory that allows people to assess the strength of arguments in practical life, which owes something both to traditional logic and to rhetoric. Chaim Perelman and Lucie Olbrechts-Tyteca incorporated theories of argumentation, topics of invention, and persuasive principles taken from rhetoric in their Traité de l’argumentation (1958), which became known in English as The new rhetoric (1969). Since then theorists of communication, working partly from linguistics, partly from ideas about mass communications and public relations, and partly from theories of information connected with computer science, have begun to interact with the newly flourishing historians of rhetoric to find new ways of incorporating the insights of the ancient arts of rhetoric and dialectic in a modern and postmodern framework.
- Howell, W. S. (1971). Eighteenth century British logic and rhetoric. Princeton: Princeton University Press.
- Mack, P. (1993). Renaissance argument: Valla and Agricola in the traditions of rhetoric and dialectic. Leiden: Brill.
- Monfasani, J. (1976). George of Trebizond: A biography and a study of his rhetoric and logic. Leiden: Brill.
- Ong, W. J. (1958). Ramus, method, and the decay of dialogue: From the art of discourse to the art of reason. Cambridge, MA: Harvard University Press.
- Perelman, C., & Olbrechts-Tyteca, L. (1958). Traité de l’argumentation: La nouvelle rhétorique. Paris: Presses Universitaires de France. (Published in English as The new rhetoric: A treatise on argumentation [trans. J. Wilkinson & P. Weaver]. Notre Dame, IN: University of Notre Dame Press, 1969).
- Toulmin, S. E. (1958). The uses of argument. Cambridge: Cambridge University Press.