Defeasible Classifications and Inferences from Definitions

• Main Authors: Douglas Walton, Fabrizio Macagno
• Format: Article
• Language: English
• Published: University of Windsor 2010-03-01
• Series: Informal Logic
• Subjects: argumentation schemes; inference; common knowledge; classifications
• Online Access: https://informallogic.ca/index.php/informal_logic/article/view/692

We contend that it is possible to argue reasonably for and against arguments from classifications and definitions, provided they are seen as defeasible (subject to exceptions and critical questioning). Arguments from classification of the most common sorts are shown to be based on defeasible reasoning of various kinds represented by patterns of logical reasoning called defeasible argumentation schemes. We show how such schemes can be identified with heuristics, or short-cut solutions to a problem. We examine a variety of arguments of this sort, including argument from abductive classification, argument from causal classification, argument from analogy-based classification and arguments from classification based on generalizations.