Rhetoric and dialectic

The structure of a disputation

Step 1: A magister at the university decided on a question and allocated the roles of respondens (respondent) and opponens (opponent, or, generally, opponents). In an initial session the magister introduced the question as a dialectical question to be answered by yes or no.
Step 2: The respondens chose one of these answers, and gave arguments for his position. The opponens (or opponentes) attacked his arguments and his position with counter-arguments.
Step 3: The respondens was given the space to respond to the counter-arguments, and give new arguments against the counter-arguments and for his initial position.
Step 4: The magister decided who had won the debate, and gave his final solution (solutio) to the question.

The game of arguing

To train the skill of disputing, several exercises were incorporated in the university curriculum. Obligationes (from the term obligatio, obligation or liability) were debates in which one committed oneself to uphold or deny a certain initial statement, after which one was then compelled to also uphold or deny everything that logically followed from that initial statement. It was a game of logical trickery, each party trying to lure the other in admitting to something impossible. Another exercise was the quodlibet, a special kind of disputation about a question on any topic and raised by anyone. The challenge was to be quick on one’s intellectual feet and show the ability to respond to questions of every nature and about any subject.

In the ninth century a new work entered the rhetorical curriculum: Alcuin’s Disputatio de rhetorica. In the eleventh and twelfth century a range of new rhetorical commentaries and treatises on the ars dictaminis (the art of composing letters) became a firm part of rhetoric. In rhetorical manuals the discipline was further divided up into specific, practical branches: the ars poetica, ars praedicandi, ars notariae, etcetera.

In the thirteenth century, together with the influx of Aristotelian logical texts, Aristotle’s Rhetoric was reintroduced in the Latin West, in a Latin translation of Herman the German (Hermannus Allemannus). This had an enormous influence on the development of the art of rhetoric: in constructing a general theory of persuasion, Aristotle firmly connected rhetoric to the arts of dialectic and logic. His philosophical approach was avidly picked up in the later Middle Ages.

Logica Vetus

Logica Vetus (Old Logic) is the set of logical works that were in available in the libraries and book collections of medieval Europe from the start. Several works of Aristotle are at the heart of this set, but some of his works came to the Latin West at a later point in time. These are not a part of Logica Vetus, but of Logica Nova, the new translations of Aristotle’s remaining logical treatises that came to the Latin West in the twelfth century. Many of the treatises of the Logica Vetus were made available by Boethius, who, in the late fifth/early sixth century made it his project to translate from Greek to Latin all the works of Plato and Aristotle and to provide commentaries on them. We have his translation of Aristotle's Categories and On Interpretation, and Porphyry’s Isagoge. He also composed supplementary works, such as the Book of Six Principles and works about syllogisms, a crucial tool for logical reasoning. The texts of Logica Vetus played a major role in the formation of the discipline of dialectic and logic. They were studied from the early Middle Ages on, and remained in use in the times of the medieval universities.

In manuscript Darmstadt, Universität- und Landesbibliothek, Hs. 2282, Lady Dialectic is depicted in the middle of the image. Above her crown, the words ‘dialectica domina’ can be read. She holds a snake in her left hand to symbolize the treacherousness of logical reasoning. In her right hand she holds a Porphyrian tree, a classic illustration of the ‘scale of being’. At the top of the tree is the most abstract ‘substance’, at the bottom the most concrete: ‘homo’, man on the left, and on the right in this case, rather curiously, ‘deus’, god.

At the top of the page, the two arch-philosophers, Plato and Aristotle, are engaged in a dialectical argument, as their typical hand gestures show. On the left, Plato is seated, on the right his student Aristotle.

On either side of Dialectic’s feet (notice her pointy shoes), two more philosophers are shown: Socrates (Plato’s teacher) on the left and ‘Magister Adam’ on the right. It is assumed that this was Adam de Parvo Ponte, a master who taught on the petit pont (small bridge) in Paris.

Handbooks with collections of logical texts set out in a certain format testify to this. This manuscript is an example: Paris, BnF, Lat. 17806. Here on fol. 218r we can see a column for commentary on the left of the text, and two columns on the right. The lower margin is also typically large to house large amounts of notes and comments.