On The Validity of a Simple Argument for Moral Error Theory

In The Myth of Morality Richard Joyce presents a simple and very influential argument for the truth of moral error theory. In this paper I point out that (i) the argument does not have the form Joyce attributes to it, (ii) the argument is not valid in an extensional propositional logic and (iii) on the most natural way of explicating the meanings of the involved terms, it remains invalid. I conclude that more explanation is needed if we are to accept this particular argument for moral error theory.     

The blaze of her splendors: Suggestions about revitalizing fallacy theory

Criticisms of fallacy theory have been lodged from many different directions. In this paper, I consider the classic criticism of incompleteness by DeMorgan, Finocchiaro's claim that fallacies probably exist only in the mind of the interpreter, McPeck's claim that fallacies are at best context-dependent and Paul's complaints about the teaching of fallacies. I seek not merely to defend fallacy theory against unfair criticisms but also to learn from the criticisms what can be done in order to make fallacy theory a viable theory of criticism. I argue that this will involve several changes: rethinking of the nature of fallacy; addressing some theoretical issues; and presenting fallacy theory in a more rigorous fashion. The paper concludes with reflections on how Quine's ontological advice about the resolution of ontological disputes might be applied to the issue of whether or not there are fallacies.     

The Relation between Formal and Informal Logic

The issue of the relationship between formal and informal logic depends strongly on how one understands these two designations. While there is very little disagreement about the nature of formal logic, the same is not true regarding informal logic, which is understood in various (often incompatible) ways by various thinkers. After reviewing some of the more prominent conceptions of informal logic, I will present my own, defend it and then show how informal logic, so understood, is complementary to formal logic.     

Argumentation and Evidence

This essay explores the role of informal logicand its application in the context of currentdebates regarding evidence-based medicine. This aim is achieved through a discussion ofthe goals and objectives of evidence-basedmedicine and a review of the criticisms raisedagainst evidence-based medicine. Thecontributions to informal logic by StephenToulmin and Douglas Walton are explicated andtheir relevance for evidence-based medicine isdiscussed in relation to a common clinicalscenario: hypertension management. This essayconcludes with a discussion on the relationshipbetween clinical reasoning, rationality, andevidence. It is argued that informal logic hasthe virtue of bringing explicitness to the roleof evidence in clinical reasoning, and bringssensitivity to understanding the role ofdialogical context in the need for evidence inclinical decision making.     

Building A General Theory of Meta‐Argumentation

This article presents a critical analysis of the main modern approaches to the problem of meta‐argumentation and suggests a method for developing a general conception of meta‐argumentation. A set of theoretical‐methodological difficulties (aporias) along this path is revealed. Overcoming these aporias would constitute the main steps toward developing the body of a theory of meta‐argumentation.     

The Uses of Argument in Mathematics

Stephen Toulmin once observed that ‘it has never been customary for philosophers to pay much attention to the rhetoric of mathematical debate’ [Toulmin et al., 1979, An Introduction to Reasoning, Macmillan, London, p. 89]. Might the application of Toulmin’s layout of arguments to mathematics remedy this oversight? Toulmin’s critics fault the layout as requiring so much abstraction as to permit incompatible reconstructions. Mathematical proofs may indeed be represented by fundamentally distinct layouts. However, cases of genuine conflict characteristically reflect an underlying disagreement about the nature of the proof in question.     

The Construction of Issues: Pleading Theory and Practice, Relevance in Pragmatics, and the Confrontation Stage in the Pragma-Dialectical Theory of Argumentation

Legal theory and practice, particularly on the exchange of pleadings, are referred to as a means of examining current thinking in pragmatics on relevance. The rules of pleadings suggest that the concept of relevance as used in pragmatics is emptied of any meaning and that theories of argumentation have not sufficiently taken into account the preliminary construction which issues to be argued about require.     

A Concept Divided: Ralph Johnson's Definition of Argument

Ralph Johnson's Manifest Rationality (2000) is a major contribution to the field of informal logic, but the concept of argument that is central to its project suffers from a tension between the components that comprise it. This paper explores and addresses that tension by examining the implications of each of five aspects of the definition of argument.     

Facts and Possibilities: A Model‐Based Theory of Sentential Reasoning

This article presents a fundamental advance in the theory of mental models as an explanation of reasoning about facts, possibilities, and probabilities. It postulates that the meanings of compound assertions, such as conditionals (if) and disjunctions (or), unlike those in logic, refer to conjunctions of epistemic possibilities that hold in default of information to the contrary. Various factors such as general knowledge can modulate these interpretations. New information can always override sentential inferences; that is, reasoning in daily life is defeasible (or nonmonotonic). The theory is a dual process one: It distinguishes between intuitive inferences (based on system 1) and deliberative inferences (based on system 2). The article describes a computer implementation of the theory, including its two systems of reasoning, and it shows how the program simulates crucial predictions that evidence corroborates. It concludes with a discussion of how the theory contrasts with those based on logic or on probabilities.     

The Repeatability Argument and the Non-Extensional Bundle Theory

I present a new objection to Bundle Theory. The objection rests on the repeatability of universals, and targets every version of Bundle Theory that assumes that concrete particulars constituted by the same universals are numerically identical. The only way that bundle theorists can elude this objection is to admit the possibility of distinct bundles constituted by the same universals. If even this view is untenable, then Bundle Theory as such is hopeless. Finally, I show how the present inquiry reshapes the dialectical relationship between Bundle Theory and the principle of Identity of Indiscernibles.     

Rectifying the Mischaracterization of Logic by Mental Model Theorists

Khemlani et al. (2018) mischaracterize logic in the course of seeking to show that mental model theory (MMT) can accommodate a form of inference (, let us label it) they find in a high percentage of their subjects. We reveal their mischaracterization and, in so doing, lay a landscape for future modeling by cognitive scientists who may wonder whether human reasoning is consistent with, or perhaps even capturable by, reasoning in a logic or family thereof. Along the way, we note that the properties touted by Khemlani et al. as innovative aspects of MMT-based modeling (e.g., nonmonotonicity) have for decades been, in logic, acknowledged and rigorously specified by families of (implemented) logics. Khemlani et al. (2018) further declare that is “invalid in any modal logic.” We demonstrate this to be false by our introduction (Appendix A) of a new propositional modal logic (within a family of such logics) in which is provably valid, and by the implementation of this logic. A second appendix, B, partially answers the two-part question, “What is a formal logic, and what is it for one to capture empirical phenomena?”     

Highly reflective reasoners show no signs of belief inhibition

The processes underlying individual differences in reasoning performance are not entirely understood. What do people who do well on reasoning tasks where beliefs and logic conflict do differently from other people? Because abundant evidence shows that even poorer reasoners detect these conflicts, it has been suggested that individual differences in reasoning performance arise from inhibition failures later in the reasoning process. The present paper argues that a minority of highly skilled reasoners may deviate from this general reasoning process from an early stage. Two studies investigated signs of belief inhibition using a lexical access paradigm (Study 1) and a negative priming paradigm (Study 2). Study 1 showed that while other people exhibited signs of belief inhibition following a belief–logic conflict, people with the highest disposition for cognitive reflection did not. In Study 2, this finding was replicated and similar results were also obtained when comparing groups with higher and lower general cognitive ability. Two possible explanations are discussed.     

Argument as Inquiry in a Postmodern Context

Argumentation is a form of communication, rather than an application of(formal) logic, and is used in communicative activity as a means forinquiry, although it is more typically thought of as bringing inquiry toclosure. Thus interpretation is an intrinsic and crucial aspect ofconversational (interactive) argumentation. In order to further thisunderstanding of argumentative activity, I propose a procedure forinterpretation that draws upon hermeneutic phenomenology. In response tocriticisms by argumentation theorists (and others) who understand thistradition as oriented to psychological, perceptual, or textual objects, Iargue that hermeneutic phenomenology supports methods for analysis ofpublic communicative activity. The resulting conception of thick argumentation responds to contemporary (postmodern) claims that argumentation valorizes univocity, stasis, and certainty at the expense ofthe pluralism, fluctuation, and range of epistemic results thatcharacterize discourse in the public sphere.     

Argumentation as Rule-Justified Claims: Elements of a Conceptual Framework for the Critical Analysis of Argument

The paper outlines a conceptual framework for the critical assessment of argumentation which differs in some of its core characteristics from conventional approaches: it is resolutely semantic rather than formal in its method; it centers on obligations rather than beliefs; and its analytical focus is on the contingent necessity of conclusions, rather than on their persuasiveness or formal validity. The paper briefly illustrates the applications of this conceptual framework by reanalyzing a couple of examples taken from the argumentation analysis literature.     

Some Aspects of Polyadic Inductive Logic

We give a brief account of some de Finetti style representation theorems for probability functions satisfying Spectrum Exchangeability in Polyadic Inductive Logic, together with applications to Non-splitting, Language Invariance, extensions with Equality and Instantial Relevance.     

The ad Hominem argument as an informal fallacy

This article outlines criteria for the evaluation of the argumentum ad hominem (argument against the person, or personal attack in argument) that is traditionally a part of the curriculum in informal logic. The argument is shown to be a kind of criticism which works by shifting the burden of proof in dialogue through citing a pragmatic inconsistency in an arguer's position. Several specific cases of ad hominem argumentation which pose interesting problems in analyzing this type of criticism are studied.     

An overview of algorithmic approaches to compute optimum entropy distributions in the expert system shell MECore (extended version)

The expert system shell MECore provides a series of knowledge management operations to define probabilistic knowledge bases and to reason under uncertainty. To provide a reference work for MECore algorithmics, we bring together results from different sources that have been applied in MECore and explain their intuitive ideas. Additionally, we report on our ongoing work regarding further development of MECore's algorithms to compute optimum entropy distributions and provide some empirical results. Altogether this paper explains the intuition of important theoretical results and their practical implications, compares old and new algorithmic approaches and points out their benefits as well as possible limitations and pitfalls.     

Second order inductive logic and Wilmers' principle

We extend the framework of Inductive Logic to Second Order languages and introduce Wilmers' Principle, a rational principle for probability functions on Second Order languages. We derive a representation theorem for functions satisfying this principle and investigate its relationship with the first order principles of Regularity and Super Regularity.