Formalizing Informal Logic

Douglas Walton, Thomas F. Gordon


This paper presents a formalization of informal logic using the Carneades Argumentation System (CAS), a formal, computational model of argument that consists of a formal model of argument graphs and audiences. Conflicts between pro and con arguments are resolved using proof standards, such as preponderance of the evidence. CAS also formalizes argumentation schemes. Schemes can be used to check whether a given argument instantiates the types of argument deemed normatively appropriate for the type of dialogue.


informal logic; formal argumentation systems; real arguments; premise acceptability; conductive argument; RSA triangle; relevance; sufficiency.

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ISSN: 0824-2577