scholarly journals Defeasible Classifications and Inferences from Definitions

2010 ◽  
Vol 30 (1) ◽  
pp. 34 ◽  
Author(s):  
Douglas Walton ◽  
Fabrizio Macagno
Keyword(s):  
Logical Reasoning ◽  
Defeasible Reasoning ◽  
Argumentation Schemes ◽  
Defeasible Argumentation ◽  
Argument From Analogy ◽  
Critical Questioning

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.

scholarly journals Story Similarity in Arguments from Analogy

2012 ◽  
Vol 32 (2) ◽  
pp. 190 ◽  
Author(s):  
Douglas Walton
Keyword(s):  
Hybrid Model ◽  
Common Knowledge ◽  
Argumentation Schemes ◽  
Argumentation Scheme ◽  
Abstract Representations ◽  
Argument From Analogy ◽  
Model Similarity

In this paper a hybrid model of argument from analogy is presented that combines argumentation schemes and story schemes. One premise of the argumentation scheme for argument from analogy in the model claims that one case is similar to another. Story schemes are abstract representations of stories (narratives, explanations) based on common knowledge about how sequences of actions and events we are familiar with can normally be expected to unfold. Story schemes are used (a) to model similarity between two cases, and (2) as the basis of evidence to support the similarity premise of an argument from analogy. Four examples of argument from analogy are used to test the theory.

scholarly journals Arguments of statutory interpretation and argumentation schemes

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Fabrizio Macagno ◽  
Douglas Walton
Keyword(s):  
Common Law ◽  
Logical Structure ◽  
Argumentation Schemes ◽  
Statutory Interpretation ◽  
Critical Questions ◽  
Defeasible Argumentation ◽  
Argumentation Structure

AbstractIn this paper it is shown how certain defeasible argumentation schemes can be used to represent the logical structure of the most common types of argument used for statutory interpretation both in civil and common law. The method is based on an argumentation structure in which the conclusion, namely, the meaning attributed to a legal source, is modeled as a claim that needs that is be supported by pro and con defeasible arguments. The defeasible nature of each scheme is shown by means of critical questions, which identify the default conditions for the accepting interpretative arguments and provide a method for evaluating a given argument as weak or strong.

scholarly journals Justification of Argumentation Schemes

2005 ◽  
Vol 3 ◽  
Author(s):  
Douglas Walton
Keyword(s):  
Expert Opinion ◽  
Human Reasoning ◽  
Argumentation Schemes ◽  
Case Study Method ◽  
Defeasible Argumentation ◽  
Different Types ◽  
Comparative Examination ◽  
Argument From Expert Opinion ◽  
Pragmatic Justification

Argumentation schemes are forms of argument that capture stereotypical patterns of human reasoning, especially defeasible ones like argument from expert opinion, that have proved troublesome to view deductively or inductively. Much practical work has already been done on argumentation schemes, proving their worth in A1 [19], but more precise investigations are needed to formalize their structures. The problem posed in this paper is what form justification of a given scheme, as having a certain precise structure of inference, should take. It is argued that defeasible argumentation schemes require both a systematic and a pragmatic justification, of a kind that can only be provided by the case study method of collecting key examples of arguments of the types traditionally classified as fallacies, and subjecting them to comparative examination and analysis. By this method, postulated structures for schemes can be formulated as hypotheses to solve three kinds of problems: (1) how to classify such arguments into different types, (2) how to identify their premises and conclusions, and (3) how to formulate the critical questions used to evaluate each type of argument.

scholarly journals Defining Marriage: Classification, Interpretation, and Definitional Disputes

2016 ◽  
Vol 36 (3) ◽  
pp. 309
Author(s):  
Fabrizio Macagno
Keyword(s):  
Argumentation Schemes ◽  
Same Sex ◽  
Same Sex Couples ◽  
State Of Affairs

The classification of a state of affairs under a legal category can be considered as a kind of con- densed decision that can be made explicit, analyzed, and assessed us- ing argumentation schemes. In this paper, the controversial conflict of opinions concerning the nature of “marriage” in Obergefell v. Hodges is analyzed pointing out the dialecti- cal strategies used for addressing the interpretive doubts. The dispute about the same-sex couples’ right to marry hides a much deeper disa- greement not only about what mar- riage is, but more importantly about the dialectical rules for defining it.

scholarly journals Algorithmic definitions for KLM-style defeasible disjunctive Datalog

2020 ◽  
Vol 32 (2) ◽  
Author(s):  
Matthew Morris ◽  
Tala Ross ◽  
Thomas Meyer
Keyword(s):  
Logic Programming ◽  
Programming Language ◽  
Systematic Approach ◽  
Axiomatic Approach ◽  
Logical Reasoning ◽  
Defeasible Reasoning ◽  
Basic Form ◽  
Logic Programming Language ◽  
Rational Closure ◽  
Plausible Inference

Datalog is a declarative logic programming language that uses classical logical reasoning as its basic form of reasoning. Defeasible reasoning is a form of non-classical reasoning that is able to deal with exceptions to general assertions in a formal manner. The KLM approach to defeasible reasoning is an axiomatic approach based on the concept of plausible inference. Since Datalog uses classical reasoning, it is currently not able to handle defeasible implications and exceptions. We aim to extend the expressivity of Datalog by incorporating KLM-style defeasible reasoning into classical Datalog. We present a systematic approach for extending the KLM properties and a well-known form of defeasible entailment: Rational Closure. We conclude by exploring Datalog extensions of less conservative forms of defeasible entailment: Relevant and Lexicographic Closure. We provide algorithmic definitions for these forms of defeasible entailment and prove that the definitions are LM-rational.

scholarly journals Advances in the Theory of Argumentation Schemes and Critical Questions

2008 ◽  
Vol 27 (3) ◽  
pp. 267 ◽  
Author(s):  
David Godden ◽  
Douglas Walton
Keyword(s):  
Burden Of Proof ◽  
Informal Logic ◽  
Argumentation Schemes ◽  
Critical Questions ◽  
The Relationship ◽  
Theoretical Issues ◽  
Argument Reconstruction ◽  
Ultimate Nature

This paper begins a working through of Blair’s (2001) theoretical agenda concerning argumentation schemes and their attendant critical questions, in which we propose a number of solutions to some outstanding theoretical issues. We consider the classification of schemes, their ultimate nature, their role in argument reconstruction, their foundation as normative categories of argument, and the evaluative role of critical questions.We demonstrate the role of schemes in argument reconstruction, and defend a normative account of their nature against specific criticisms due to Pinto (2001). Concerning critical questions, we propose an account on which they are founded in the R.S.A. cogency standard, and develop an account of the relationship between critical questions and burden of proof. Our ultimate aim is to initiate a reconciliation between dialectical and informal logic approaches to the schemes.

scholarly journals Linguistic barriers to logical reasoning: a new perspective on Aristotelian syllogisms

2018 ◽  
Vol 60 ◽  
pp. 453-468
Author(s):  
Andreas Haida ◽  
Luka Crnič ◽  
Yosef Grodzinsky
Keyword(s):  
Experimental Studies ◽  
Logical Reasoning ◽  
Error Rates ◽  
Syllogistic Reasoning ◽  
Reasoning Strategies ◽  
Linguistic Barriers ◽  
Reasoning Errors ◽  
New Perspective ◽  
Analytical Tools

Experimental studies investigating logical reasoning performance show very high errorrates of up to 80% and more. Previous research identified scalar inferences of the sentencesof logical arguments as a major error source. We present new analytical tools to quantify theimpact of scalar inferences on syllogistic reasoning. Our proposal builds on a new classificationof Aristotelian syllogisms and a closely linked classification of reasoning behaviors/strategies.We argue that the variation in error rates across syllogistic reasoning tasks is in part due toindividual variation: reasoners follow different reasoning strategies and these strategies playout differently for syllogisms of different classes.Keywords: syllogisms, reasoning errors, individual variation, scalar inferences.

Palindromes and the “Law of 11”

1985 ◽  
Vol 32 (5) ◽  
pp. 46-47
Author(s):  
Clarence J. Dockweller
Keyword(s):  
Grade Level ◽  
Logical Reasoning ◽  
Intermediate Grade ◽  
The Law

Several years ago, McGinty and Eisenberg (1978) described an extenive classification of numbers according to the number of step required to form a palindrome (a number that reads the same forward or backward, like 707 or 12021). The number 89. for example, requires twenty-four reversals and sum before the palindrome 8813200023188 is obtained. Although finding palindrome is intriguing in itself, other inte resting things can be done with them. Logical reasoning can be fruit fully applied to palindromic patterns. The patterns, related concepts, and discssuions are very appropriate for enrichment experience at the intermediate grade level with extenions for all higher levels. We shall consider several example that suggest the “law of 11.”

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