In an attempt to overcome the traditional casual neglect of the study of the informal fallacies, we here treat one fallacy, the ad baculum, at an adequate theoretical level in order to determine how it may best be understood as a fallacy. We conclude, after following through a number of plausible routes of tracking down the essential fallaciousness of the ad baculum, that the type of phenomenon apparently so typically thought to constitute ad baculum by the texts is not, so (...) far as we can tell, an instance of a logical fallacy. (shrink)

"What Type of Argument is an Ad Verecundiam?".

If one looks to the current textbook lore for reliable taxonomic and analytical information about the petitio principii, one is met with conceptual disarray and much too much nonsense. The present writers have recently attempted to furnish the beginnings of a theoretical reconstruction of this fallacy which is at once faithful to its formidable complexity yet useful as guide for its detection and avoidance. The fact is that the petitio has had a lengthy and interesting history, and in this paper (...) we shall want to explore certain features of its development, such as it may have been. The principal origins of the concept of circular argument are to be found in Aristotle. The Aristotelian doctrine recurs with variations in the sophismata literature of the middle ages and in logic texts and manuals right up to the present day. (shrink)

If one looks to the current textbook lore for reliable taxonomic and analytical information about the petitio principii, one is met with conceptual disarray and much too much nonsense. The present writers have recently attempted to furnish the beginnings of a theoretical reconstruction of this fallacy which is at once faithful to its formidable complexity yet useful as guide for its detection and avoidance. The fact is that the petitio has had a lengthy and interesting history, and in this paper (...) we shall want to explore certain features of its development, such as it may have been. The principal origins of the concept of circular argument are to be found in Aristotle. The Aristotelian doctrine recurs with variations in the sophismata literature of the middle ages and in logic texts and manuals right up to the present day. (shrink)

A common reaction among idealist philosophers to the classical syntactic characterization of proof so crisply articulated by Tarski is an urgent but inchoate Angst that something momentous is missing, an awesome intimation of bereftness. The simple fact is that in many pursuits proof involves an empirical appeal, an operation that Tarski excludes from the domain of proof and assigns to the company of confirmation. In Tarski’s terms, empirical statements never even admit of the predicate true, let alone proved, unless perhaps (...) they hanker after truth or proof in the limit in some dimly understood and always unsuccessful way. Some sources of queasiness about the syntactic account are not hard to pinpoint. On the syntactic account, the injunction “Prove it!” can never be fulfilled, or even well-formedly uttered, in regard to an empirical statement, ┏∅, therefore ∅┓ is valid for any well-formed ∅ in a given first-order language, for any theorem, t, ┏∅, therefore t┓ is an impeccable proof for any well-formed ∅ in the classical languages. It is easy to think, with Bradley, that there is an important and legitimate, if not formally well-articulated sense of proof, characteristic of much of philosophical reasoning and argumentation, which is badly misrepresented by the syntactic conception. The kind of proof often sought after in theology, and sought after and found in the law, and the experimental and social sciences, is not purely syntactic. Idealists, of course, have frequently expressed dissatisfaction with the Tarski conception of truth. We will here extend this skepticism to the Tarski notion of proof. (shrink)

In an attempt to overcome the traditional casual neglect of the study of the informal fallacies, we here treat one fallacy, the ad baculum, at an adequate theoretical level in order to determine how it may best be understood as a fallacy. We conclude, after following through a number of plausible routes of tracking down the essential fallaciousness of the ad baculum, that the type of phenomenon apparently so typically thought to constitute ad baculum by the texts is not, so (...) far as we can tell, an instance of a logical fallacy. (shrink)

This article analyses the fallacy of wrenching from context, using the dialectical notions of commitment and implicature as tools. The data, a set of key examples, is used to sharpen the conceptual borderlines around the related fallacies of straw man, accent, misquotation, and neglect of qualifications. According to the analysis, the main characteristics of wrenching from context are the manipulation of the meaning of the other’s statement through devices such as the use of misquotations, selective quotations, and quoting out of (...) context. The theoretical tools employed in the analysis are pragmatic theories of meaning and a dialectical model of commitment, used to explain how and why a standpoint is distorted. The analysis is based on a conception of fallacies as deceptive strategic moves in a game of dialogue. As a consequence, our focus is not only on misquotations as distortions of meaning, but on how they are used as dialectical tools to attack an opponent or win a dispute. Wrenching from context is described as a fallacy of unfairly attributing a commitment to another party that he never held. Its power as a deceptive argumentation tactic is based on complex mechanisms of implicit commitments and on their misemployment to improperly suggest an attribution of commitment. (shrink)

In this paper we show how dialogue-based theories of argumentation can contribute to the construction of effective systems of dispute resolution. Specifically we consider the role of persuasion in online dispute resolution by showing how persuasion dialogues can be functionally embedded in negotiation dialogues, and how negotiation dialogues can shift to persuasion dialogues. We conclude with some remarks on how persuasion dialogues might be modelled is such a way as to allow them to be implemented in a mechanical or computerized (...) system of dialogue or dialogue management. (shrink)

This article presents a philosophical framework for physician-family ethical decision-making for the controversial cases of withdrawal, initiation, or continuation of treatment for spina bifida infants. The well-known criteria for selective treatment proposed by Lorber are shown to be ethically sub-optimal on the grounds that they are based on a general conception of the decision framework that is open to serious criticisms and questioning.We propose a model of joint physician-family decision-making that we think represents a more rational method of balancing patient (...) autonomy with the professional expertise and international moral norms of physicians. We raise serious reservations about the wisdom of allowing the state to intervene too strenously in this type of decision, in many cases. (shrink)

This article presents a philosophical framework for physician-family ethical decision-making for the controversial cases of withdrawal, initiation, or continuation of treatment for spina bifida infants. The well-known criteria for selective treatment proposed by Lorber are shown to be ethically sub-optimal on the grounds that they are based on a general conception of the decision framework that is open to serious criticisms and questioning.We propose a model of joint physician-family decision-making that we think represents a more rational method of balancing patient (...) autonomy with the professional expertise and international moral norms of physicians. We raise serious reservations about the wisdom of allowing the state to intervene too strenously in this type of decision, in many cases. (shrink)

This paper is a reply to Stephen Davis' ‘A Defence of the Free Will Defence’. With the aid of some elementary modal logic, some of the inner workings of Davis’ argument are explored, and the nature of the opposition of the Davis argument to the Mackie thesis is made plainer. It is concluded herein that while the Davis argument is interesting and illuminating, it is not conclusive, as Davis appears to think, and that the burden of proof remains on the (...) opponent of the Mackie thesis, i.e., the Free Will Defence defender. (shrink)

A common reaction among idealist philosophers to the classical syntactic characterization of proof so crisply articulated by Tarski is an urgent but inchoate Angst that something momentous is missing, an awesome intimation of bereftness. The simple fact is that in many pursuits proof involves an empirical appeal, an operation that Tarski excludes from the domain of proof and assigns to the company of confirmation. In Tarski’s terms, empirical statements never even admit of the predicate true, let alone proved, unless perhaps (...) they hanker after truth or proof in the limit in some dimly understood and always unsuccessful way. Some sources of queasiness about the syntactic account are not hard to pinpoint. On the syntactic account, the injunction “Prove it!” can never be fulfilled, or even well-formedly uttered, in regard to an empirical statement, ┏∅, therefore ∅┓ is valid for any well-formed ∅ in a given first-order language, for any theorem, t, ┏∅, therefore t┓ is an impeccable proof for any well-formed ∅ in the classical languages. It is easy to think, with Bradley, that there is an important and legitimate, if not formally well-articulated sense of proof, characteristic of much of philosophical reasoning and argumentation, which is badly misrepresented by the syntactic conception. The kind of proof often sought after in theology, and sought after and found in the law, and the experimental and social sciences, is not purely syntactic. Idealists, of course, have frequently expressed dissatisfaction with the Tarski conception of truth. We will here extend this skepticism to the Tarski notion of proof. (shrink)

How should we evaluate an argument in which two witnesses independently testify to some claim? In fact what would happen is that the testimony of the second witness would be taken to corroborate that of the first to some extent, thereby boosting up the plausibility of the first argument from testimony. But does that commit the fallacy of double counting, because the second testimony is already taken as independent evidence supporting the claim? Perhaps the corroboration effect should be considered illogical, (...) since each premise should be seen as representing a separate reason in a convergent argument for accepting the claim as plausible. In this paper, we tackle the problem using argumentation schemes and argument diagramming. We examine a number of examples, and come up with two hypotheses that offer methods of analyzing and evaluating this kind of evidence. (shrink)

The aim of this investigation is to explore the role of argumentation schemes in enthymeme reconstruction. This aim is pursued by studying selected cases of incomplete arguments in natural language discourse to see what the requirements are for filling in the unstated premises and conclusions in some systematic and useful way. Some of these cases are best handled using deductive tools, while others respond best to an analysis based on defeasible argumentations schemes. The approach is also shown to work reasonably (...) well for weak arguments, a class of arguments that has always been difficult to analyze without the principle of charity producing a straw man. (shrink)

While courts depend on expert opinions in reaching sound judgments, the role of the expert witness in legal proceedings is associated with a litany of problems. Perhaps most prevalent is the question of under what circumstances should testimony be admitted as expert opinion. We review the changing policies adopted by American courts in an attempt to ensure the reliability and usefulness of the scientific and technical information admitted as evidence. We argue that these admissibility criteria are best seen in a (...) dialectical context as a set of critical questions of the kind commonly used in models of argumentation. (shrink)

This paper explains how to use a new software tool for argument diagramming available free on the Internet, showing especially how it can be used in the classroom to enhance critical thinking in philosophy. The user loads a text file containing an argument into a box on the computer interface, and then creates an argument diagram by dragging lines from one node to another. A key feature is the support for argumentation schemes, common patterns of defeasible reasoning historically know as (...) topics . Several examples are presented, as well as the results of an experiment in using the system with students in a university classroom. (shrink)

The situationally disqualifying ad hominem attack is an argumentative move in critical dialogue whereby one participant points out certain features in his adversary's personal situation that are claimed to make it inappropriate for this adversary to take a particular point of view, to argue in a particular way, or to launch certain criticisms. In this paper, we discuss some examples of this way of arguing. Other types of ad hominem argumentation are discussed as well and compared with the situationally disqualifying (...) type. The socalled Houtlosser Dilemma highlights the danger of unconditionally condoning ad hominem arguments. We propose a classification of ad hominem, and a more restrictive use of the term 'circumstantial'. Finally, we discuss whether ad hominem arguments are (always?) to be rejected as fallacious. (shrink)

We present a formal, mathematical model of argument structure and evaluation, taking seriously the procedural and dialogical aspects of argumentation. The model applies proof standards to determine the acceptability of statements on an issue-by-issue basis. The model uses different types of premises (ordinary premises, assumptions and exceptions) and information about the dialectical status of statements (stated, questioned, accepted or rejected) to allow the burden of proof to be allocated to the proponent or the respondent, as appropriate, for each premise separately. (...) Our approach allows the burden of proof for a premise to be assigned to a different party than the one who has the burden of proving the conclusion of the argument, and also to change the burden of proof or applicable proof standard as the dialogue progresses from stage to stage. Useful for modeling legal dialogues, the burden of production and burden of persuasion can be handled separately, with a different responsible party and applicable proof standard for each. Carneades enables critical questions of argumentation schemes to be modeled as additional premises, using premise types to capture the varying effect on the burden of proof of different kinds of questions. (shrink)

The paper considers contemporary models of presumption in terms of their ability to contribute to a working theory of presumption for argumentation. Beginning with the Whatelian model, we consider its contemporary developments and alternatives, as proposed by Sidgwick, Kauffeld, Cronkhite, Rescher, Walton, Freeman, Ullmann-Margalit, and Hansen. Based on these accounts, we present a picture of presumptions characterized by their nature, function, foundation and force. On our account, presumption is a modal status that is attached to a claim and has the (...) effect of shifting, in a dialogue, a burden of proof set at a local level. Presumptions can be analysed and evaluated inferentially as components of rule-based structures. Presumptions are defeasible, and the force of a presumption is a function of its normative foundation. This picture seeks to provide a framework to guide the development of specific theories of presumption. (shrink)

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. (shrink)

This paper studies the modelling of legal reasoning about evidence within general theories of defeasible reasoning and argumentation. In particular, Wigmore's method for charting evidence and its use by modern legal evidence scholars is studied in order to give a formal underpinning in terms of logics for defeasible argumentation. Two notions turn out to be crucial, viz. argumentation schemes and empirical generalisations.

In response to the growing recognition of informal logic as a discipline in its own right, this collection of essays from leading contributors in the field provides the formative knowledge and historical context required to understand the development of a so far little studied subject area.

Develops a logical analysis of dialogue in which two or more parties attempt to advance their own interests. It includes a classification of the major types of dialogues and a discussion of several important informal fallacies.

This book provides a systematic analysis of many common argumentation schemes and a compendium of 96 schemes. The study of these schemes, or forms of argument that capture stereotypical patterns of human reasoning, is at the core of argumentation research. Surveying all aspects of argumentation schemes from the ground up, the book takes the reader from the elementary exposition in the first chapter to the latest state of the art in the research efforts to formalize and classify the schemes, outlined (...) in the last chapter. It provides a systematic and comprehensive account, with notation suitable for computational applications that increasingly make use of argumentation schemes. (shrink)

IT is strange that the informal fallacies should strike us as such obvious breaches of thinking and advocacy, yet should have met with such little success in finding a respectable home within mature logical theory. It might seem that respectable and mature logical theory is most mature and most respectable in the theory of propositions, and that its maturity and respectability in the other logical domains rapidly diminish in inverse proportion to the susceptibility of those domains to be reduced to (...) the logic of propositions. But we are not anxious to promote so severe a view of theoretical accomplishment, and we shall suppose that, at the very least, the informal fallacies have a degree of systematicity that will at once advance our understanding of them nicely beyond the level of intuitive impressions, and also place into retirement the hopelessly inadequate accounts that litter too many otherwise admirable textbooks. (shrink)

A problem for dialogue models of argumentation is to specify a set of conditions under which an opponent’s claims, offered in support of a standpoint under dispute, ought to be challenged. This project is related to the issue of providing a set of acceptability conditions for claims made in a dialogue. In this paper, we consider the conditions of suspicion and trust articulated by Jacobs (Alta, 2003), arguing that neither are acceptable as general conditions for challenge. We propose a third (...) condition that attempts to mark a middle ground between suspicion and trust. (shrink)

In this chapter, we explore the development and importance of the connection between argumentation and artificial intelligence. Specifically, we show that the influence of argumentation on AI has occurred within a framework that is consistent with the basic approach of Pragma-Dialectics. While the pragma-dialectical approach is typically conceived of as applying primarily to argumentation occurring between human agents, we show that the basic features of this approach can consistently be applied in a virtual context, whereby the goal-directed activities of, and (...) exchanges of information between, artificial agents are regulated by procedural rules. (shrink)

The Nature and Status of Critical Questions in Argumentation Schemes.

The aim of the paper is to present a typology of argument schemes. In first place, we found it helpful to define what an argument scheme is. Since many argument schemes found in contemporary theories stem from the ancient tradition, we took in consideration classical and medieval dialectical studies and their relation with argumentation theory. This overview on the main works on topics and schemes provides a summary of the main principles of classification. In the second section, Walton’s theory is (...) briefly explained to introduce the schemes classification and its different levels. At least, the final part shows the main application of the schemes in computing and AI. -/- . (shrink)

International Commentary on Evidence, 2006 Vol. 4, Issue 2, 1-47 . [link to online version posted].