Topical logic is the logic of topical argument, a branch of

rhetoric Rhetoric () is the art of persuasion, which along with grammar and logic (or dialectic), is one of the three ancient arts of discourse. Rhetoric aims to study the techniques writers or speakers utilize to inform, persuade, or motivate parti ...

developed in the Late Antique period from earlier works, such as Aristotle's ''

Topics Topic, topics, TOPIC, topical, or topicality may refer to: Topic / Topics * Topić, a Slavic surname * ''Topics'' (Aristotle), a work by Aristotle * Topic (chocolate bar), a brand of confectionery bar * Topic (DJ), German musician * Topic (g ...

'' and Cicero's ''Topica''. It consists of heuristics for developing

argument An argument is a statement or group of statements called premises intended to determine the degree of truth or acceptability of another statement called conclusion. Arguments can be studied from three main perspectives: the logical, the dialectic ...

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 Differentiis'' (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 Inferences are steps in reasoning, moving from premises to logical consequences; etymologically, the word '' infer'' means to "carry forward". Inference is theoretically traditionally divided into deduction and induction, a distinction that in ...

, 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 Rodolphus Agricola ( la, Rudolphus Agricola Phrisius; August 28, 1443, or February 17, 1444 – October 27, 1485) was a pre-Erasmian humanist of the Northern Low Countries, famous for his knowledge of Latin and Greek. He was an educator, musici ...

(1479) made large claims for this method, as an aspect of

dialectic Dialectic ( grc-gre, διαλεκτική, ''dialektikḗ''; related to dialogue; german: Dialektik), also known as the dialectical method, is a discourse between two or more people holding different points of view about a subject but wishing ...

(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 Philip Melanchthon. (born Philipp Schwartzerdt; 16 February 1497 – 19 April 1560) was a German Lutheran reformer, collaborator with Martin Luther, the first systematic theologian of the Protestant Reformation, intellectual leader of the Lu ...

and Petrus Ramus.Harold J. Berman, ''Law and Revolution, II: The Impact of the Protestant Reformations on the Western Legal Tradition'' (2006), p. 112. The debate fed into the later development of

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 during the St. Bartholomew's Day massacre in August 1572. Accor ...

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