Topical logic
Encyclopedia
Topical logic is the logic of topical argument, a branch of rhetoric
developed in the Late Antique period from earlier works, such as Aristotle
's Topics
and Cicero
's Topica. It consists of heuristics for developing argument
s, which are in the first place plausible rather than rigorous, from commonplaces (topoi or loci). In other words, therefore, it consists of standardized ways of thinking up debating techniques from existing, thought-through positions. The actual practice of topical argument was much developed by Roman lawyers. Cicero took the theory of Aristotle to be an aspect of rhetoric. As such it belongs to inventio in the classic fivefold division of rhetoric.
The standard classical work on topical logic was the De Topicis Differentiae (On Topical Differentiae) by Boethius. Differentiae refer to case analysis
, being the differentiations used to distinguish the cases into which a question is divided. Besides Aristotle and Cicero, Boethius built on Themistius
. In terminology, the Greek axioma and topos in Boethius became the Latin maxima propositio (maxim
, universal truth) and locus.
In the Middle Ages
topical logic became a theory of inference
, for which the name "axiomatic topics" has been suggested. Abelard wanted to complete a theory of entailment
by invoking the loci in Boethius to fill in conditionals, a flawed if bold development. Peter of Spain
, in his De locis, developed the ideas of Boethius.
The De inventione dialectica of Rodolphus Agricola
(1479) made large claims for this method, as an aspect of dialectic
(traditionally contrasted with rhetoric) subordinated to inventio. The precise relationship of "dialectic" and "rhetoric" remained vexed well into the sixteenth century, hinging on the role assigned to loci. It was expounded in different fashions by Philipp Melanchthon
and Petrus Ramus
. The debate fed into the later development of Ramism
.
Rhetoric
Rhetoric is the art of discourse, an art that aims to improve the facility of speakers or writers who attempt to inform, persuade, or motivate particular audiences in specific situations. As a subject of formal study and a productive civic practice, rhetoric has played a central role in the Western...
developed in the Late Antique period from earlier works, such as Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
's Topics
Topics (Aristotle)
The Topics is the name given to one of Aristotle's six works on logic collectively known as the Organon. The other five are:*Categories*De Interpretatione*Prior Analytics*Posterior Analytics*On Sophistical Refutations...
and Cicero
Cicero
Marcus Tullius Cicero , was a Roman philosopher, statesman, lawyer, political theorist, and Roman constitutionalist. He came from a wealthy municipal family of the equestrian order, and is widely considered one of Rome's greatest orators and prose stylists.He introduced the Romans to the chief...
's Topica. It consists of heuristics for developing argument
Argument
In philosophy and logic, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.Argument may also refer to:-Mathematics and computer science:...
s, which are in the first place plausible rather than rigorous, from commonplaces (topoi or loci). In other words, therefore, it consists of standardized ways of thinking up debating techniques from existing, thought-through positions. The actual practice of topical argument was much developed by Roman lawyers. Cicero took the theory of Aristotle to be an aspect of rhetoric. As such it belongs to inventio in the classic fivefold division of rhetoric.
The standard classical work on topical logic was the De Topicis Differentiae (On Topical Differentiae) by Boethius. Differentiae refer to case analysis
Case analysis
Case analysis is one of the most general and applicable methods of analytical thinking, depending only on the division of a problem, decision or situation into a sufficient number of separate cases. Analysing each such case individually may be enough to resolve the initial question...
, being the differentiations used to distinguish the cases into which a question is divided. Besides Aristotle and Cicero, Boethius built on Themistius
Themistius
Themistius , named , was a statesman, rhetorician, and philosopher. He flourished in the reigns of Constantius II, Julian, Jovian, Valens, Gratian, and Theodosius I; and he enjoyed the favour of all those emperors, notwithstanding their many differences, and the fact that he himself was not a...
. In terminology, the Greek axioma and topos in Boethius became the Latin maxima propositio (maxim
Maxim (philosophy)
A maxim is a ground rule or subjective principle of action; in that sense, a maxim is a thought that can motivate individuals.- Deontological ethics :...
, universal truth) and locus.
In the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
topical logic became a theory of inference
Inference
Inference is the act or process of deriving logical conclusions from premises known or assumed to be true. The conclusion drawn is also called an idiomatic. The laws of valid inference are studied in the field of logic.Human inference Inference is the act or process of deriving logical conclusions...
, for which the name "axiomatic topics" has been suggested. Abelard wanted to complete a theory of entailment
Entailment
In logic, entailment is a relation between a set of sentences and a sentence. Let Γ be a set of one or more sentences; let S1 be the conjunction of the elements of Γ, and let S2 be a sentence: then, Γ entails S2 if and only if S1 and not-S2 are logically inconsistent...
by invoking the loci in Boethius to fill in conditionals, a flawed if bold development. Peter of Spain
Peter of Spain
Peter of Spain or, in Latin, Petrus Hispanus is the Mediaeval author of Tractatus, later known as Summulae logicales magistri Petri Hispani , a standard textbook on logic...
, in his De locis, developed the ideas of Boethius.
The De inventione dialectica of Rodolphus Agricola
Rodolphus Agricola
Rodolphus Agricola was a pre-Erasmian humanist of the northern Low Countries, famous for his supple Latin and one of the first north of the Alps to know Greek well...
(1479) made large claims for this method, as an aspect of dialectic
Dialectic
Dialectic is a method of argument for resolving disagreement that has been central to Indic and European philosophy since antiquity. The word dialectic originated in Ancient Greece, and was made popular by Plato in the Socratic dialogues...
(traditionally contrasted with rhetoric) subordinated to inventio. The precise relationship of "dialectic" and "rhetoric" remained vexed well into the sixteenth century, hinging on the role assigned to loci. It was expounded in different fashions by Philipp Melanchthon
Philipp Melanchthon
Philipp Melanchthon , born Philipp Schwartzerdt, was a German reformer, collaborator with Martin Luther, the first systematic theologian of the Protestant Reformation, intellectual leader of the Lutheran Reformation, and an influential designer of educational systems...
and Petrus Ramus
Petrus Ramus
Petrus Ramus was an influential French humanist, logician, and educational reformer. A Protestant convert, he was killed during the St. Bartholomew's Day Massacre.-Early life:...
. The debate fed into the later development of Ramism
Ramism
Ramism was a collection of theories on rhetoric, logic and pedagogy based on the teachings of Petrus Ramus, a French academic, philosopher and Huguenot convert who was murdered in 1572.According to Jonathan Israel, Ramism-Development:...
.
Further reading
- Catherine Kavanagh, Eruigenian Developments of Ciceronian Topical Theory, pp. 1–30 in Stephen Gersh, Bert Roest (editors), Medieval and Renaissance Humanism: Rhetoric, Representation and Reform (2003).
- Peter Mack, Renaissance argument: Valla and Agricola in the traditions of rhetoric and dialectic (1993)