J. Anthony Blair is a prominent international figure in argumentation studies. He is among the originators of informal logic, an author of textbooks on the informal logic approach to argument analysis and evaluation and on critical thinking, and a founder and editor of the journal Informal Logic. Blair is widely recognized among the leaders in the field for contributing formative ideas to the argumentation literature of the last few decades. This selection of key works provides insights into the history of (...) the field of argumentation theory and various related disciplines. It illuminates the central debates and presents core ideas in four main areas: Critical Thinking, Informal Logic, Argument Theory and Logic, Dialectic and Rhetoric. (shrink)

There is an important disagreement in contemporary epistemology over the possibility of non-epistemic reasons for belief. Many epistemologists argue that non-epistemic reasons cannot be good or normative reasons for holding beliefs: non-epistemic reasons might be good reasons for a subject to bring herself to hold a belief, the argument goes, but they do not offer any normative support for the belief itself. Non-epistemic reasons, as they say, are just the wrong kind of reason for belief. Other epistemologists, however, argue that (...) there can be cases where non-epistemic reasons directly offer normative support for the beliefs a subject holds. -/- My aim in this paper is to remove an apparent obstacle for the view that there can be non-epistemic normative reasons for belief, by showing that the existence of non-epistemic reasons for belief does not conflict with epistemic standards for the assessment of inference. More specifically, I aim to show that the following principles are compatible: -/- Epistemic Norm of Inference (ENI): Necessarily, for all subjects, S, and inferences, I: I is a good inference for S only if S can gain a (doxastically) epistemically justified belief in I’s conclusion on the basis of I’s premises. -/- Non-Epistemic Reasons for Belief (NERB): Possibly, for some subject, S, reason, R, and belief, B: R is a good (i.e., normative) reason for S to hold B, and R is not an epistemic reason for B. -/- Guidance: For all subjects S, potential reasons R, and beliefs/actions φ: In order for R to count as a normative reason for S to φ, it must be possible for S to take R into account as relevant to the determination of whether S ought to φ. -/- One might naturally think that these principles conflict, for if there are non-epistemic reasons for belief, then they must guide deliberation, and in guiding deliberation, they would violate epistemic standards. The aim of this paper is to show that no such conflict need arise. -/- Section 2 of the paper proceeds to set out the concept of an inference, and to sketch an epistemic framework for the assessment of inferences and arguments. Section 3 sets out the distinction between normative and motivating reasons, and briefly defends the view that there can be non-epistemic reasons for beliefs. Section 4 shows that non-epistemic reasons for belief are compatible with epistemic standards for inference, because any time a reason R is a good non-epistemic reason for a subject S to hold a belief B, there is an epistemically good inference available to S which takes R as a premise and which concludes with the meta-belief that S ought to hold B. So the paper employs a level-connecting principle between normative reasons for φ-ing and epistemic reasons for believing that one ought to φ. The paper ends with clarifications of that level-connecting principle, and responses to three objections. (shrink)

This paper advances an approach to relevance grounded on patterns of material inference called argumentation schemes, which can account for the reconstruction and the evaluation of relevance relations. In order to account for relevance in different types of dialogical contexts, pursuing also non-cognitive goals, and measuring the scalar strength of relevance, communicative acts are conceived as dialogue moves, whose coherence with the previous ones or the context is represented as the conclusion of steps of material inferences. Such inferences are described (...) using argumentation schemes and are evaluated by considering 1) their defeasibility, and 2) the acceptability of the implicit premises on which they are based. The assessment of both the relevance of an utterance and the strength thereof depends on the evaluation of three interrelated factors: 1) number of inferential steps required; 2) the types of argumentation schemes involved; and 3) the implicit premises required. (shrink)

Although in some contexts the notions of an ordinary argument’s presumption, assumption, and presupposition appear to merge into the one concept of an implicit premise, there are important differences between these three notions. It is argued that assumption and presupposition, but not presumption, are basic logical notions. A presupposition of an argument is best understood as pertaining to a propositional element (a premise or the conclusion) e of the argument, such that the presupposition is a necessary condition for the truth (...) of e or for a term in e to have a referent. In contrast, an assumption of an argument pertains to the argument as a whole in that it is integral to the reasoning or inferential structure of the argument. A logical assumption of an argument is essentially a proposition that must be true in order for the argument aside from that proposition to be fully cogent. Nothing that is both comparable and distinguishing can be said about presumptions of arguments. Rather, presumptions of arguments are distinctively conventional; they are introduced through conventional rules (e.g., those that concern how to treat promises). So not all assumptions and not all presuppositions of arguments are presumptions of those arguments, although all presumptions of arguments are either assumptions or presuppositions of those arguments. This account avoids making the (monological) notion of presumption vacuous and dissolving the distinction between assumption and presumption, which is a vulnerability of alternative views such as Hansen’s and Bermejo-Luque’s, as is shown. (shrink)

This paper explores two persistent questions in the literature on presumptions: the place and the nature of presumptions in law and legal argumentation. These questions were originally raised by James Bradley Thayer, one of the masters of the Law of Evidence and the author of the classic chapter devoted this subject in A preliminary treatise on Evidence. Like Thayer, I believe that these questions deserve attention. First the paper shows that the connection between presumptions and argumentation is a constant feature (...) in the literature on presumptions, since its foundation in the Middle Ages to modern times. James Bradley Thayer was probably the last jurist who clearly saw that presumptions belong to argumentation. Second, the paper examines two sources of controversy in the language of presumptions. First, “presumption” is an ambiguous word in the legal discourse. As a result, it is almost impossible to provide a clear and succinct answer to the question “What is a presumption?”. Second, there are at least four reconstructions of the concept of presumption whose merits and shortcomings are relevant to explore. The analysis presented here may be of interest for legal and non-legal scholars and, hopefully, it may help to shed light on the possibilities and limits of an interdisciplinary dialogue about presumptions. (shrink)

This volume presents a selection of papers reflecting key theoretical issues in argumentation theory. Its six sections are devoted to specific themes, including the analysis and evaluation of argumentation, argument schemes and the contextual embedding of argumentation. The section on general perspectives on argumentation discusses the trends of empiricalization, contextualization and formalization, offers descriptions of the analytical and evaluative tools of informal logic, and highlights selected principles that argumentation theorists do and do not agree upon. In turn, the section on (...) linguistic approaches to argumentation focuses on the problem of distinguishing between explanation and argument, while also elaborating on the role of verbal indicators of argument schemes. All essays included in this volume point out notable recent developments in the study of argumentation. (shrink)

Implicatures are described as particular forms reasoning from best explanation, in which the para-digm of possible explanations consists of the possible semantic interpretations of a sentence or a word. The need for explanation will be shown to be triggered by conflicts between presumptions, namely hearer’s dialogical expectations and the presumptive sentence meaning. What counts as the best explanation can be established on the grounds of hierarchies of presumptions, dependent on dialogue types and interlocutors’ culture.

In argumentation, as elsewhere, speakers strategically engage favourable presumptions by manifestly making themselves accountable for their communicative efforts. Such strategies provide the addressee with reasons to regard the speaker as accountable in specific ways and, via that regard for the speaker, with situation-specific rationales for responding positively to what the speaker says. This paper identifies some resources available to arguers for strengthening, elaborating, and focusing such special presumptions. The paper offers an analysis of Barbara Jordan’s “Statement on the Articles of (...) Impeachment” as illustrative of these resources for strengthening a speaker’s ethos. (shrink)

Metaphorical meaning can be analyzed as triggered by an apparent communicative breach, an incongruity that leads to a default of the presumptive interpretation of a vehicle. This breach can be solved through contextual renegotiations of meaning guided by the communicative intention, or rather the presumed purpose of the metaphorical utterance. This paper addresses the problem of analyzing the complex process of reasoning underlying the reconstruction of metaphorical meaning. This process will be described as a type of abductive argument, aimed at (...) explaining how the vehicle can best contribute to the purpose of the utterance. This type of reasoning involves the analysis of the possible predicates that can be and usually are attributed to the vehicle, and the selection of the one that can support the implicit conclusion constituting the communicative goal of the metaphorical utterance. Metaphorical meaning, in this perspective, becomes the outcome of a complex process of meaning reconstruction aimed at providing the best explanation of the function of the vehicle within a discourse move. (shrink)

The article outlines a general epistemological theory of argument: a theory that regards providingjustified belief as the principal aim of argumentation, and defends it instrumentalistically. After introducing some central terms of such a theory, answers to its central questions are proposed: the primary object and structure of the theory, the function of arguments, which is to lead to justified belief, the way such arguments function, which is to guide the addressee's cognizing, objective versus subjective aspects of argumentation, designing different types (...) of argument. Then the notion of ' valid argument' is defined and criteria for the adequate use of such arguments are introduced. Finally, this conception is justified as, among others, leading to more true beliefs than competing conceptions. (shrink)

The epistemologists Biro and Siegel have raised two objections against the pragma-dialectical approach to argumentation. According to the first objection the pragma-dialectical theory is not genuinely normative. According to the second objection the rejection of justificationism by pragma-dialecticians is unwarranted: they reject justificationism prematurely and they are not consistent in accepting some arguments (‘justifications’) as sound. The first objection is based on what we regard as the misconception that the goal of resolving differences of opinion cannot provide a normative approach. (...) In response to the second objection we argue that in pragma-dialectics, the notion of argument, and related notions, are defined in a non-justificatory manner. (shrink)

An overview of the epistemological approach to argumentation, explaining what it is, justifying it as better than a rhetorical or a consensual ist approach.systematizing the main directions and theories according to their criteria for good argumentation and presenting their contributions to major topics of argumentation theory. Also. an introduction to the articles of the two special issues of Informal Logic about the epistemological approach to argumentation.

An approach to argument macrostructure -- The dialectical nature of argument -- Toulmin's problematic notion of warrant -- The linked-convergent distinction, a first approximation -- Argument structure and disciplinary perspective : the linked-convergent versus multiple-co-ordinatively compound distinctions -- The linked-convergent distinction, refining the criterion -- Argument structure and enthymemes -- From analysis to evaluation.

This paper shows how reasoning from best explanation combines with linguistic and factual presumptions during the process of retrieving a speaker’s intention. It is shown how differences between presumptions need to be used to pick the best explanation of a pragmatic manifestation of a dialogical intention. It is shown why we cannot simply jump to an interpretative conclusion based on what we presume to be the most common purpose of a speech act, and why, in cases of indirect speech acts, (...) we need to depend on an abductive process of interpretation. (shrink)

In ‘The making of argumentation theory’ van Eemeren and van Haaften describe the contributions made to the five components of a full-fledged research program of argumentation theory by four prominent approaches to the discipline: formal dialectics, rhetoric/pragmalinguistics, informal logic, and pragma-dialectics. Most of these approaches do not contribute to all components, but to some in particular. Starting from the pragma-dialectical view of the relationship between dialectical reasonableness and rhetorical effectiveness – the crucial issue in argumentation theory – van Eemeren and (...) van Haaften explain the positions taken by representatives from the approaches discussed and indicate where they differ from the pragma-dialectical approach. It transpires that approaches focusing on dialectical reasonableness are, next to pragma-dialectics, formal dialectics and informal logic; approaches focusing on rhetorical effectiveness are, next to pragma-dialectics, rhetoric and pragmalinguistics, and the informal logician Tindale. When it comes to the relationship between dialectical reasonableness and rhetorical effectiveness, some interest in it is shown in rhetoric and pragmalinguistics, but only in pragma-dialectics and in Tindale’s work is it a real focus. The main difference between Tindale’s view and the pragma-dialectical view is that in pragma-dialectics the decisive role in deciding about reasonableness is assigned to a code of conduct for reasonable argumentative discourse and in Tindale’s approach this role is assigned to Tindale’s interpretation of the Perelmanian universal audience. (shrink)

There is an important disagreement in contemporary epistemology over the possibility of non-epistemic reasons for belief. Many epistemologists argue that non-epistemic reasons cannot be good or normative reasons for holding beliefs: non-epistemic reasons might be good reasons for a subject to bring herself to hold a belief, the argument goes, but they do not offer any normative support for the belief itself. Non-epistemic reasons, as they say, are just the wrong kind of reason for belief. Other epistemologists, however, argue that (...) there can be cases where non-epistemic reasons directly offer normative support for the beliefs a subject holds. My aim in this paper is to remove an apparent obstacle for the view that there can be non-epistemic normative reasons for belief, by showing that the existence of non-epistemic reasons for belief does not conflict with epistemic standards for the assessment of inferences. More specifically, I aim to show that the following principles are compatible. Epistemic norm of inference (ENI): necessarily, for all subjects S and inferences I: I is a good inference for S only if S can gain a (doxastically) epistemically justified belief in I’s conclusion on the basis of I’s premises. Non-epistemic reasons for belief (NERB): possibly, for some subject S, reason R, and belief B: R is a good (i.e., normative) reason for S to hold B, and R is not an epistemic reason for B. Guidance: for all subjects S, potential reasons R, and beliefs/actions φ: In order for R to count as a normative reason for S to φ, it must be possible for S to take R into account as relevant to the determination of whether S ought to φ. One might naturally think that these principles conflict, for if there are non-epistemic reasons for belief, then they must guide deliberation, and in guiding deliberation, they would violate epistemic standards. The aim of this paper is to show that no such conflict need arise. Section 2 of the paper sets out the concept of an inference, and sketches an epistemic framework for the assessment of inferences and arguments. Section 3 sets out the distinction between normative and motivating reasons, discusses motivational internalism about reasons, and briefly defends the view that there can be non-epistemic reasons for beliefs. Section 4 shows that non-epistemic reasons for belief are compatible with epistemic standards for inference and with a deliberative guidance constraint on normative reasons, because any time a reason R is a good non-epistemic reason for a subject S to hold a belief B, there is an epistemically good inference available to S which takes R as a premise and which concludes with the meta-belief that S ought to hold B. So the paper employs an indirect level-connecting principle between normative reasons for φ-ing and epistemic reasons for believing that one ought to φ. The paper ends with clarifications of that level-connecting principle, and responses to three objections. (shrink)

Douglas Walton’s multitudinous contributions to the study of argumentation seldom, if ever, directly engage with argumentation in mathematics. Nonetheless, several of the innovations with which he is most closely associated lend themselves to improving our understanding of mathematical arguments. I concentrate on two such innovations: dialogue types (§1) and argumentation schemes (§2). I argue that both devices are much more applicable to mathematical reasoning than may be commonly supposed.

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

In this paper, we will explore two initiatives that focus on the importance of employing logical theories in educating people how to think and reason properly, one in Poland: The Lvov-Warsaw School; the other in North America: The Informal Logic Initiative. These two movements differ in the logical means and skills that they focus on. However, we believe that they share a common purpose: to educate students in logic and reasoning (logical education conceived as a process) so that they may (...) be able to apply their skills to analyze the issues in their society (logical culture as a result of logical education). The aim of the paper is to justify this claim by exploring research objectives and products that are common to both movements. (shrink)

While, in common usage, objectivity is usually regarded as a virtue, and failures to be objective as vices, this concept tends to be absent in argumentation theory. This paper will explore the possibility of taking objectivity as an argumentative virtue. Several problems immediately arise: could objectivity be understood in positive terms— not only as mere absence of bias? Is it an attainable ideal? Or perhaps objectivity could be explained as a combination of other virtues?

This paper presents what we call with Plantin an argumentative cell as an unit which is inspired by Toulmin’s layout of arguments, in order to analyse two major effects of pseudo-objectivity in argumentation. Four problems of Toulmin's layout will be tackled: Data are only described as facts, the definition of Backing is blurred, but it may be linked with sources of information and extended to Data, the dialectical component of the Rebuttal needs to be extended to concessions, and dealing with (...) complex argumentation within such a model is quite difficult. Treating these problems will highlight the rhetorical possibility of a "bias of objectivity": numerous arguments that use starting points which may appear to be objective or shared in order to impose a standpoint to the addressee. This bias can be seen in at least two rhetorical strategies: the first one is using facts as arguments without signs of evidentiality in grounds for the argument. The second one is delivering opinions as apparently collectively shared. (shrink)

In this paper, I propose that the inquiry known as a/the theory of argument is the “invention” of Trudy Govier, using that term in its rhetorical sense, viz., the process of choosing ideas appropriate to the subject. In her paper, “Is a Theory of Argument Possible?” Govier used the idea of theory of argument to focus her discussion on problems in argument analysis and evaluation that came to light in the 1970s and 1980s. The idea of a theory of argument (...) was already there but Govier “discovered” it in the sense that she made its potential clear. (shrink)

In this paper I provide support for the view that at least some forms of adversariality in argumentation are legitimate. The support comes from Aristotle’s theory of illegitimate adversarial argumentation in dialectical contexts: his theory of eristic in his work On Sophistical Refutations. Here Aristotle develops non-epistemic standards for evaluating the legitimacy of dialectical procedures, standards which I propose can be understood in terms of the pragmatic notion of context as common ground. Put briefly, Aristotle makes the answerer’s meaning in (...) giving assent in dialectical contexts the basis for further moves in the game of dialectic. Moves which subvert the answerer’s meaning or do not solicit the answerer’s consent are marked as eristic, i.e. adversarial in a problematic sense. I conclude with remarks on what Aristotle’s theory may teach us about how semantic features relate to the normative evaluation of argumentation. (shrink)

The study of presumptions has intensified in argumentation theory over the last years. Although scholars put forward different accounts, they mostly agree that presumptions can be studied in deliberative and epistemic contexts, have distinct contextual functions, and promote different kinds of goals. Accordingly, there are “practical” and “cognitive” presumptions. In this paper, I show that the differences between practical and cognitive presumptions go far beyond contextual considerations. The central aim is to explore Nicholas Rescher’s contention that both types of presumptions (...) have a closely analogous pragmatic function, i.e., that practical and cognitive presumptions are made to avoid greater harm in circumstances of epistemic uncertainty. By comparing schemes of practical and cognitive reasoning, I show that Rescher’s contention requires qualifications. Moreover, not only do practical and cognitive presumptions have distinct pragmatic functions, but they also perform different dialogical functions and, in some circumstances, cannot be defeated by the same kinds of evidence. Hence, I conclude that the two classes of presumptions merit distinct treatment in argumentation theory. (shrink)

This essay addresses the collapse/incoherence problem for normative frameworks that contain both fundamental values and rules for promoting those values. The problem is that in some cases, we would bring about more of the fundamental value by violating the framework’s rules than by following them. In such cases, if the framework requires us to follow the rules anyway, then it appears to be incoherent; but if it allows us to make exceptions to the rules, then the framework “collapses” into one (...) that doesn’t make use of rules in the first place. The chapter begins with an examination of happiness and truth as fundamental values in Mill’s work, which lead into parallel versions of the collapse/incoherence problem in ethics and epistemology. It then sets out the collapse problem for rule-consequentialist approaches in ethics, truth-directed accounts of justification in epistemology, and epistemological approaches to argument cogency. The chapter closes with discussion of two potential solutions to the problem. (shrink)

I argue for the distinction between presuming that p and maintaining that presumably p. In order to make sense of this distinction, I defend a non-inferentialist conception of presumptions and offer an account of the correctness conditions for both presumptions and presumptive inferences. I characterize presumptions as a type of constative speech-act having certain semantic correctness conditions. In turn, regarding presumptive inferences, my strategy is to provide the correctness conditions for the use of an epistemic modal such as “presumably.” This (...) epistemic modal is characterized as a force indicator for speech-acts of concluding in complex speech-acts of arguing involving presumptive inferences. (shrink)

In The Uses of Argument, Stephen Toulmin proposed a model for the layout of arguments: claim, data, warrant, qualifier, rebuttal, backing. Since then, Toulmin’s model has been appropriated, adapted and extended by researchers in speech communications, philosophy and artificial intelligence. This book assembles the best contemporary reflection in these fields, extending or challenging Toulmin’s ideas in ways that make fresh contributions to the theory of analysing and evaluating arguments.

On the standard view, all presumptions share the same deontic function: they asymmetrically allocate the burden of proof. But what, exactly, does this function amount to? Once presumptions are rejected, do they place the burden of arguing, the burden of explanation, or the most general burden of reasoning on their opponents? In this paper, I take into account the differences between cognitive and practical presumptions and argue that the standard accounts of deontic function are at least ambiguous, and likely implausible. (...) As a result, they require qualifications. (shrink)

Lilian Bermejo-Luque has posed these questions:1.What is the relationship between presumption and presumptive inference? 2.What are the correctness conditions for presumptions and presumptive inferences? Cohen’s method of relevant variables, Toulmin’s model, and Rescher’s theory of plausibility suggest answers. An inference is presumptive just in case its warrant transfers presumption from its premises to its conclusion. A warrant licencing an inference from the claim that an empirical property φ holds to the claim that some other property ψ holds is backed by (...) observation of a constant conjunction of those properties. The stronger the backing, the stronger the warrant. Warrants may be defeated by instances of φ holding in conjunction with some property χ and ψ not holding. The method of relevant variables directs us to organize such defeating properties into relevant variables. We then test the strength of a warrant by seeing how many variables fail to have a value which defeats the warrant. The more variables with no defeater, the stronger the warrant. We may construct a canonical ordering of the relevant variables by ranking them according to the plausibility of their including defeating values. We may evaluate the strength not only of empirically backed warrants, but warrants backed by institutional rules, such as a branch of law, or by a priori intuited connections between properties. An inference rule will be presumptive just in case the plausibility of its warrant being defeated is below some specified level. (shrink)

We all seem to have a sense of what good and bad arguments are, and there is a long history—focusing on fallacies—of trying to provide objective standards that would allow a clear separation of good and bad arguments. This contribution discusses the limits of attempts to determine the quality of arguments. It begins with defining bad arguments as those that deviate from an established standard of good arguments. Since there are different conceptualizations of “argument”—as controversy, as debate, and as justification—and (...) since arguments in each of these senses can be used for different purposes, a first problem is that we would need a large variety of standards for “good” arguments. After this, the contribution focuses in particular on proposals made in the literature on how to assess the quality of arguments in the sense of justification. It distinguishes three problems of assessment: How to determine whether reasons are acceptable, whether reasons are sufficient to justify the conclusion, and how to identify arguments in real-world speech acts and texts? It is argued that limitations of argument assessment result from unavoidable relativism: The assessment of many—if not most—arguments depends on the epistemic situation of the evaluator. (shrink)

In this paper we present an interdisciplinary approach that concerns the problem of argument acceptance in an agronomy setting. We propose a computational cognitive model for argument acceptance based on the dual model system in cognitive psychology. We apply it in an agronomy setting within a French national project on durum wheat.

Moral dissensus may arise first because persons may disagree over the warrants licensing inferring an evaluative conclusion from premises asserting that properties alleged evaluatively relevant hold. This results in seeing different properties as evaluatively relevant. Secondly, such properties will frequently not be descriptive but interpretive, asserting some nomic connection. Persons may disagree over what evaluatively relevant properties hold in a given case. We explore the possibilities for argumentation to resolve these two types of disagreement.

Epistemology and informal logic have overlapping and broadly similar subject matters. A principle of methodological symmetry is: philosophical theories of sufficiently similar subject matters should engage similar methods. Suppose the best way to do epistemology is in highly formalized ways, with a large role for mathematical methods. The symmetry principle suggests this is also the best way to do the logic of the reasoning and argument, the subject matter of informal logic. A capitulation to mathematics is inimical to informal logicians, (...) yet formal methods and mathematical models are an emerging force in epistemology. What is to be done? What’s sauce for the goose of epistemology is sauce for the gander of informal logic. (shrink)

Presupposition has been described in the literature as closely related to the listener’s knowledge and the speaker’s beliefs regarding the other’s mind. However, how is it possible to know or believe our interlocutor’s knowledge? The purpose of this paper is to find an answer to this question by showing the relationship between reasoning, presumption and language. Presupposition is analyzed as twofold reasoning process: on the one hand, the speaker by presupposing a proposition presumes that his interlocutor knows it; on the (...) other hand, the listener reconstructs the propositions taken for granted and assesses them against the shared presumptions. The possibility of reconstructing a presupposition is distinguished from its assessment, where the consistency of the presupposition with the shared or common ground is evaluated, and its reasonableness established. The analysis of presuppositions from an argumentative perspective provides an instrument for evaluating the reasonableness of a presupposition and understanding its dialogical effect. On this view, the dialogical force of a presupposition lies in its presumptive nature, which sets and shifts the burden of proving its unacceptability or unreasonableness. (shrink)

“Reasonable hostility” is a norm of communicative conduct initially developed by studying public exchanges in education governance meetings in local U.S. communities. In this paper I consider the norm’s usefulness for and applicability to a U.S. state-level public hearing about a bill to legalize civil unions. Following an explication of reasonable hostility and grounded practical theory, the approach to inquiry that guides my work, I describe Hawaii’s 2009, 18-hour public hearing and analyze selected seg-ments of it. I show that this (...) particular public hearing raised demands for testifiers on the anti-civil union side of the argument that reasonable hostility does not do a good job of addressing. Development of a norm of communication conduct for this practice, as well as others, must engage with the culture and time-specific beliefs that a society holds, beliefs that will shape not only how to argue but what may be argued and what must be assumed about particular categories of persons. (shrink)

Following David Hitchcock and Stephen Toulmin, this paper takes warrants to be material inference rules. It offers an account of the form such rules should take that is designed (a) to implement the idea that an argument/inference is valid only if it is entitlement preserving and (b) to support a qualitative version of evidence proportionalism. It attempts to capture what gives warrants their normative force by elaborating a concept of reliability tailored to its account of the form such rules should (...) take. (shrink)

In a priori analogies, the analogue is constructed in imagination, sharing certain properties with the primary subject. The analogue has some further property clearly consequent on those shared properties. Ceteris paribus the primary subject has that property also. The warrant involves non-empirical, e.g., moral intuition but is also defeasible. The argument is thus neither deductive nor inductive, but an additional type. In an inductive analogy, the analogues back the warrant from below. Distinguishing these two types of arguments by analogy gives (...) epistemic evaluative factors primacy over resemblance factors in classifying arguments—a prescient insight on Govier’s part. (shrink)

Relevance of premises to conclusion can be explicated through Toulmin’s notion of warrant, understood as an inference rule, albeit not necessarily formal. A normative notion of relevance requires the warrant to be reliable. To determine reliability, we propose a fourfold classification of warrants into a priori, empirical, institutional, and evaluative, with further subdivisions possible. This classification has its ancestry in classical rhetoric and recent epistemology. Distinctive to each type of warrant is the mode by which such connections are intuitively discovered (...) and the grounds on which we ultimately justify them. The classification of warrants is thus epistemic. We illustrate the difference by contrasting empirical physical with institutional intuition, and argue for the advantages of this approach over Toulmin’s conception of field dependence. (shrink)

Corroborative evidence has a dual function in argument. Primarily, it functions to provide direct evidence supporting the main conclusion. But it also has a secondary, bolstering function which increases the probative value of some other piece of evidence in the argument. This paper argues that the bolstering effect of corroborative evidence is legitimate, and can be explained as counter–rebuttal achieved through inference to the best explanation. A model (argument diagram) of corroborative evidence, representing its structure and operation as a schematic (...) pattern of defeasible argument is also supplied. In addition to explaining the operation and theoretical foundation of corroborative evidence, the model facilitates the correct analysis and guides the evaluation (assessment and critique) of corroborative evidence as it occurs in argument. (shrink)

By explaining the argument from ignorance in terms of the presumption of innocence, many textbooks in argumentation theory suggest that some arguments from ignorance might share essential features with some types of presumptive reasoning. The stronger version of this view, suggesting that arguments from ignorance and presumptive reasoning are almost indistinguishable, is occasionally proposed by Douglas Walton. This paper explores the nature and limits of the stronger proposal and argues that initial presumptions and arguments from ignorance are not closely connected. (...) There are three main reasons. First, the argument from ignorance, unlike typical presumptive reasoning, is a negative kind of inference. Second, the typical initial presumption is sensitive to a broader set of defeaters and thus assumes a higher standard of acceptability. Third, in dialectical terms, initial presumption and argument from ignorance bring different attacking rights and obligations. I conclude that Waltonian intuition is unsupported or, at best, is limited only to practical presumptions and practical arguments from ignorance. (shrink)

In a posthumous paper, Perelman discusses his decision to bring his theory of argumentation together with rhetoric rather than calling it an informal logic. This is due in part because of the centrality he gives to audience, and in part because of the negative attitude that informal logicians have to rhetoric. In this paper, I explore both of these concerns by way of considering what benefits Perelman’s work can have for informal logic, and what insights the work of informal logicians (...) might bring to the project of Perelman and Olbrechts-Tyteca. (shrink)

One takes one’s word that p when a source vouches for p and one accepts the word of that source. If the source is reliable in this case, p is acceptable. The reliability of the source is a measure of its plausibility. If a source has the relevant competence, credibility, authority, that word is acceptable. Likewise, the word may be acceptable if accompanied by a cogent argument, but presumption may be misplaced. One may recognize a presumption for a statement when (...) such recognition is not justified, the positive version of the fallacy. One may refuse to recognize a presumption for a statement when there really is a presumption for the statement, the negative version of the fallacy. The essay proceeds to explore various dimensions of when it is justified to take a source’s word for a claim, and when it is justified to reject a claim from a source. The discussion ranges over considerations of sexism and race, cultural differences, and the relationship of presumptions to fallacies. Also considered is the role of trust in taking someone’s word and the factors involved in trusting someone. (shrink)

Standards and norms for reasoning function, in part, to manage epistemic risk. Properly used, modal qualifiers like presumably have a role in systematically managing epistemic risk by flagging and tracking type-specific epistemic merits and risks of the claims they modify. Yet, argumentation-theoretic accounts of presumption often define it in terms of modalities of other kinds, thereby failing to recognize the unique risk profile of each. This paper offers a stipulative account of presumption, inspired by Ullmann-Margalit, as an inferentially generated modal (...) qualifier, “presumably, p,” distinguishing it from other, particularly epistemic modalities, e.g., standing commitments, assumptions, assertions, suppositions, hypotheses, and defeasible claims. By avoiding the tranching of inferential instruments of qualitatively different bona fides and risk profiles, this account provides a more accurate risk-rating system that better manages epistemic risk in inference, as well as contributing to the normative theory of the operation of presumption in reasoning and argument. (shrink)

The aim of this paper is to defend the claim that arguments are truth-directed, and to discuss the role that truth plays in the evaluation of arguments that are truth-directed. It concludes that the proper place of truth is in the metatheory in terms of which a theory of evaluation is to be worked out, rather than in the theory of evaluation itself as a constraint on premise adequacy.

The notions of defeasibility and defeasible reasoning have generated a great deal of interest in various research communities. Here I want to focus on their use in logic and argumentation studies. I will approach these topics from the perspective of an informal logician who finds himself struggling with some issues that surround the idea of and the deployment of the concept of defeasibility. My intention is to make those struggles as clear as I can.

We argue that Cohen’s concept of inductive or ampliative probability facilitates proper explication of sufficient strength for non-demonstrative arguments conforming to the Toulmin model. The data and claims of such arguments are singular statements. We may epistemically classify the warrants of such arguments as empirical (either physical or personal), institutional, or evaluative. Backing evidence and rebutting considerations vary with the epistemic type of warrant, but in each case the notion of ampliative probability for arguments with warrants of that type can (...) be characterized. We may then use ampliative probability to define sufficient strength and related notions for Toulmin arguments. (shrink)