In this paper I investigate the similarities betweenthe dialectical procedure in the pragma-dialecticaltheory and dialectical procedures in AI and Law. I dothis by focusing on one specific type of reasoning inlaw: analogy argumentation. I will argue that analogyargumentation is not only a heuristic forfinding new premises, but also a part of thejustification of legal decisions. The relevantcriteria for the evaluation of analogy argumentationare not to be found at the logical level of inference,but at the procedural level of the discussion. I (...) willproceed as follows. I start with an outline ofPrakken's theory of argumentation frameworks andprocedural models. Then, I will discuss Peczenik'sanalysis of analogy argumentation and try to combineit with the descriptive-normative research ofMacCormick and Summers. Finally, I propose asystematization of the criteria for the evaluation ofanalogy argumentation within the framework of apragma-dialectical notion of an argumentation scheme. (shrink)

The question of who has the burden of proof is often important in practice. We must frequently make decisions and act on the basis not of conclusive evidence but of what is reasonable to presume true. Consequently, it happens that a given practical question must be solved by referring to principles that explicitly or implicitly determine, at least partly, where the burden of proof should rest. In this essay, I consider the role of the logic of the burden of proof (...) in a debate on global justice. In particular, I ask how the logic of the burden of proof is seen by those who defend conservative positions in a debate and deny our obligations to reduce poverty beyond borders. I argue that defenders of conservative positions tend to shift the burden of proof in an unjustified way. (shrink)

This paper is an exercise in intellectual history, an attempt to understand how a specific term—”informal logic”— came to be interpreted in so many different ways. I trace the emergence and development of “informal logic” to help explain the many different meanings, how they emerged and how they are related. This paper is also, to some degree, an account of a movement that developed outside the mainstream of philosophy, whose origins lie in a desire to make logic useful (echoing Dewey).

A concept of critical thinking is developed based on the Socratic method and called accordingly a Socratic model. First the features of critical thinking stressed in this model are stated and illustrated. The Socratic method is presented and interpreted, then taken to yield a model of critical thinking. The process of internalization by which the Socratic model helps us to become critical thinkers is described. Argument analysis is considered as a widely used instructional strategy adaptable for teaching critical thinking on (...) the Socratic model. This Socratic model is advanced as one helpful way of organizing our ideas about critical thinking, helpful in unifying disparate factors and anchoring them in the humanist tradition. (shrink)

The appeal to expert opinion is an argument form that uses the verdict of an expert to support a position or hypothesis. A previous scheme-based treatment of the argument form is formalized within a Bayesian network that is able to capture the critical aspects of the argument form, including the central considerations of the expert's expertise and trustworthiness. We propose this as an appropriate normative framework for the argument form, enabling the development and testing of quantitative predictions as to how (...) people evaluate this argument, suggesting that such an approach might be beneficial to argumentation research generally. We subsequently present two experiments as an example of the potential for future research in this vein, demonstrating that participants' quantitative ratings of the convincingness of a proposition that has been supported with an appeal to expert opinion were broadly consistent with the predictions of the Bayesian model. (shrink)

The notion of “the burden of proof” plays an important role in real-world argumentation contexts, in particular in law. It has also been given a central role in normative accounts of argumentation, and has been used to explain a range of classic argumentation fallacies. We argue that in law the goal is to make practical decisions whereas in critical discussion the goal is frequently simply to increase or decrease degree of belief in a proposition. In the latter case, it is (...) not necessarily important whether that degree of belief exceeds a particular threshold (e.g., ‘reasonable doubt’). We explore the consequences of this distinction for the role that the “burden of proof” has played in argumentation and in theories of fallacy. (shrink)

A generation before Beardsley, legal scholar John Henry Wigmore invented a scheme for representing arguments in a tree diagram, aimed to help advocates analyze the proof of facts at trial. In this essay, I describe Wigmore's "Chart Method" and trace its origin and influence. Wigmore, I argue, contributes to contemporary theory in two ways. His rhetorical approach to diagramming provides a novel perspective on problems about the theory of reasoning, premise adequacy, and dialectical obligations. Further, he advances a novel solution (...) to the problem of assessing argument quality by representing the strength of argument in meeting objections. (shrink)

Disputational models of argumentation have been criticized as introducing adversariality into argumentation by mistakenly conceiving of it as minimally adversarial, and, in doing so, structurally incentivizing ancillary adversariality. As an alternative, non-adversarial models of argumentation like inquiry have been recommended. In this article I defend disputational, minimally adversarial models of disagreement-based argumentation. First, I argue that the normative kernel of minimal adversariality is properly located in the normative fabric of disagreement, not our practices of disputation. Thus, argumentation’s minimal adversariality is (...) a hereditary, rather than an acquired, trait. Second, I show how attempts to model disagreement-based argumentation non-adversarially, as co-inquiry, misrepresent the normative commitments of disagreers. Indeed, such attempts backfire in their efforts to make argumentation less adversarial, by removing the normative, discursive mechanisms by which we may hold each other to rational account for our commitments. Finally, I show how regulative models of disputation, like the Pragma-Dialectical critical discussion, are designed to minimize ancillary adversariality thereby preventing its escalation. (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)

This paper considers the probative burdens of proposing action or policy options in deliberation dialogues. Do proposers bear a burden of proof? Building on pioneering work by Douglas Walton (2010), and following on a growing literature within computer science, the prevailing answer seems to be “No.” Instead, only recommenders—agents who put forward an option as the one to be taken—bear a burden of proof. Against this view, we contend that proposers have burdens of proof with respect to their proposals. Specifically, (...) we argue that, while recommenders that Φ bear a burden of proof to show that □Φ (We should / ought to / must Φ), proposers that Φ have a burden of proof to show that ◇Φ (We may / can Φ). A burden of proposing may be defined as, which reads: Those who propose that we might Φ are obliged, if called upon, to show that Φ is possible in any of four ways which we call worldly, deontic, instrumental, and practical. So understood, burdens of proposing satisfy the standard formal definition of burden of proof. (shrink)

How do Dutch people let each other know that they disagree? What do they say when they want to resolve their difference of opinion by way of an argumentative discussion? In what way do they convey that they are convinced by each other’s argumentation? How do they criticize each other’s argumentative moves? Which words and expressions do they use in these endeavors? By answering these questions this short essay provides a brief inventory of the language of argumentation in Dutch.

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)

In this essay, Weinstein wants to address the issue of argument strength, of how strongly the premises of an argument support a conclusion. Using the framework of the Toulmin model, arguments have warrants which indicate some general connection between the premises and the conclusion of the argument. We may ask for the backing of the warrant, evidence for it. If the connection is an empirical generalization, the backing includes data supporting the generalization. But the backing may include theoretical generalizations, which (...) may explain the warrant. Furthermore, theories may be reduced by more comprehensive theories. A warrant then may ultimately be backed by some deep and very comprehensive theoretical explanation.Weinstein seeks to explicate the relation between the depth of backing for the warrant and the strength of the connection between premises and conclusion which the warrant indicates through the Model of Emerging Truth . Data relevant to confirming the theory have empir .. (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)

Koopman’s book revolves around the notion of transition, which he proposes is one of the central ideas of the pragmatist tradition but one which had not previously been fully articulated yet nevertheless shapes the pragmatist attitude in philosophy. Transition, according to Koopman, denotes “those temporal structures and historical shapes in virtue of which we get from here to there”. One of the consequences of transitionalism is the understanding of critique and inquiry as historical pro...

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)

Premise acceptability is conceptually connected to presumption. To say that a premise is acceptable just when there is a presumption in its favor is to give a first approximation to this connection. A number of popular principles of presumption suggest that whether there is a presumption for a premise, belief, or claim depends on the sources which vouch for it. Sources consist of internal belief-generating mechanisms and external testimony. Alvin Plantinga's notion of warrant lays down four conditions upon a source (...) for the belief which it generates to be warranted. We argue that there is a presumption for a premise, belief, or claim if and only if there is a presumption of warrant for that premise,belief or claim. This amounts to the thesis that there is a presumption for a belief from a challenger's point of view if and only if there is a presumption from that person's point of view that her cognitive faculties which have generated the belief have been functioning properly, in an appropriate cognitive environment, in accord with a segment of her design plan aimed at the truth, and that these faculties are reliable. In light of our argument for this thesis, we may legitimately claim that one way to determine that there is a presumption for a belief is to determine that there is a presumption of warrant for that belief, and thus that in determining whether there is a presumption for a belief or premise, we may consider the source. (shrink)

We present a computational model of dialectical argumentation that could serve as a basis for legal reasoning. The legal domain is an instance of a domain in which knowledge is incomplete, uncertain, and inconsistent. Argumentation is well suited for reasoning in such weak theory domains. We model argument both as information structure, i.e., argument units connecting claims with supporting data, and as dialectical process, i.e., an alternating series of moves by opposing sides. Our model includes burden of proof as a (...) key element, indicating what level of support must be achieved by one side to win the argument. Burden of proof acts as move filter, turntaking mechanism, and termination criterion, eventually determining the winner of an argument. Our model has been implemented in a computer program. We demonstrate the model by considering program output for two examples previously discussed in the artificial intelligence and legal reasoning literature. (shrink)

In this paper a theoretical definition that helps to explain how the logical structure of legal presumptions is constructed by applying the Carneades model of argumentation developed in artificial intelligence. Using this model, it is shown how presumptions work as devices used in evidentiary reasoning in law in the event of a lack of evidence to assist a chain of reasoning to move forward to prove or disprove a claim. It is shown how presumptions work as practical devices that may (...) be useful in cases in which there is insufficient evidence to prove the claim to an appropriate standard of proof. (shrink)

Dying is easy; comedy is hard. Comedy is sovereign. I begin with an excerpt from Bertolt Brecht’s Fugitive Conversations. Ziffel, a physicist, is chatting with the worker Kalle: For humor, I always think of the philosopher Hegel.... He had the makings of one of the greatest humorists among the philosophers.... I read his book The Great Logic once, when I had rheumatism and couldn’t move. It’s one of the greatest humorous works of world literature. It treats of the way of (...) life of concepts, those slippery, unstable, irresponsible existences; how they abuse one another and fight with knives and then sit down together to supper as though nothing had happened.... They can live... (shrink)

lt is now commonplace in fallacy inquiry for many of the traditional informal fallacies to be viewed as reasonable or nonfallacious modes of argument. Central to this evaluative shift has been the attempt to examine traditional fallacies within their wider contexts of use. However, this pragmatic turn in fallacy evaluation is still in its infancy. The true potential of a contextual approach in the evaluation of the fallacies is yet to be explored. I examine how, in the context of scientific (...) inquiry, certain traditional fallacies function by conferring epistemic gains upon inquiry. Specifically, I argue that these fallacies facilitate the progression of inquiry, particularly in the initial stages ofinquiry when the epistemic context is one of uncertainty. The conception of these fallacies that emerges is that of heuristics of reasoning in contexts of epistemic uncertainty. (shrink)

It is a feature of scientific inquiry that it proceeds alongside a multitude of non-scientific interests. This statement is as true of the scientific inquiries of previous centuries, many of which brought scientists into conflict with institutionalised religious thinking, as it is true of the scientific inquiries of today, which are conducted increasingly within commercial and political contexts. However, while the fact of the coexistence of scientific and non-scientific interests has changed little over time, what has changed with time is (...) the effect of this coexistence on scientific inquiry itself. While scientists may no longer construct their theories with various religious dictates in mind, growing commercial and political interests in science have served to distort the interpretation of science. Using the U.K.’s recent crisis with bovine spongiform encephalopathy (BSE) as my context, I examine two ways in which this distortion has occurred – the interpretation of the science of BSE by politicians and by commercial parties for the purposes of justifying policy decisions and informing the public of risk, respectively. Fallacious reasoning, I contend, is the manifestation of this distortion in these contexts. In demonstration of this claim, I examine how politicians and commercial parties alike have employed two fallacies in their assessments of the science of BSE. These fallacies extend in novel ways the set of so-called traditional informal fallacies. The interpretation of science, I conclude, is a rich context in which to conduct a study of fallacious reasoning; moreover, such a study can contribute in significant ways, I argue, to the public understanding of science. (shrink)

The world’s scientific community must be in a state of constant readiness to address the threat posed by newly emerging infectious diseases. Whether the disease in question is SARS in humans or BSE in animals, scientists must be able to put into action various disease containment measures when everything from the causative pathogen to route(s) of transmission is essentially uncertain. A robust epistemic framework, which will inform decision-making, is required under such conditions of uncertainty. I will argue that this framework (...) should have reasoning at its center and, specifically, that forms of reasoning beyond deduction and induction should be countenanced by scientists who are confronted with emerging infectious diseases. In previous articles, I have presented a case for treating certain so-called traditional informal fallacies as rationally acceptable forms of argument that can facilitate scientific inquiry when little is known about an emerging disease. In this article, I want to extend that analysis by highlighting the unique features of these arguments that makes them specially adapted to cope with conditions of uncertainty. Of course, such a view of the informal fallacies must at least be consistent with the reasoning practices of scientists, and particularly those scientists (viz. epidemiologists) whose task it is to track and respond to newly emerging infectious diseases. To this end, I draw upon examples of scientific reasoning from the UK’s BSE crisis, a crisis that posed a significant threat to both human and animal health. (shrink)

Few, if any, scientific inquiries are conducted against a background of complete knowledge, a background in which inquirers are in possession of the ‘full facts’ that relate to a particular question or issue. More often than not, scientists are compelled to conduct their deliberations in contexts of epistemic uncertainty, in which partial knowledge or even a total absence of knowledge characterise inquiry. Nowhere is this epistemic uncertainty more evident, or indeed more successfully controlled, than in the branch of scientific inquiry (...) called epidemiology. In this paper, I examine how epidemiologists overcome the unique challenges to inquiry that are posed by epistemic uncertainty. In specific terms, I contend that epidemiologists employ analogical reasoning strategies in an attempt to advance their inquiries in situations that are epistemically uncertain. The context for my claims will be the early inquiries that were conducted into the emergence of HIV/AIDS in the United States. I argue that early scientific work in relation to HIV/AIDS was directly premised upon epidemiological investigations in which analogical reasoning with hepatitis B had featured significantly. I conclude that epidemiological investigations of AIDS exemplify the capacity of analogical reasoning to advance inquiry under conditions of epistemic uncertainty. To this extent, analogical reasoning should be a concern both to those who address practical problems of uncertainty management and to those who pursue theoretical debates within argumenta-tion studies and epistemology. (shrink)

En el presente artículo utilizamos el concepto de filosofía formalizada de Hansson, así como las categorías de idealización simplificada y perfeccionista que se le asocian, con el fin de proponer un metaanálisis de tres enfoques teóricos de la argumentación, a saber, la pragmadialéctica de van Eemeren y Grootendorst, los esquemas argumentativos de Walton y el enfoque conversacional de Jacobs y Jackson, en relación con el tratamiento de las falacias como un tipo de trasgresión de reglas pragmáticas. Concluimos que mientras las (...) dos primeras están ancladas en una concepción centralizada de lo falaz, la tercera abandona toda posibilidad de normatividad. (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)

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 this overview article, we first explain what we take informal logic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informal logic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informal logic; fifth, we discuss three implications of informal logic for philosophy in particular, and take note ofpractical consequences of a more general sort.

I propose a characterization of the dialectical dimension of argumentation by considering the activity of arguing as involving a “second order intersubjectivity”. I argue that argumentative communication enables this kind of intersubjectivity as a matter of the recursive nature of acts of arguing—both as justificatory and as persuasive devices. Calling attention to this feature is a way to underline that argumentative discourses represent the explicit part of a dynamic activity, “a mechanism of rational validation”, as Rescher showed, which is a (...) practice that presupposes the possibility of attaining objectivity. (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)

We provide a retrospective of 25 years of the International Conference on AI and Law, which was first held in 1987. Fifty papers have been selected from the thirteen conferences and each of them is described in a short subsection individually written by one of the 24 authors. These subsections attempt to place the paper discussed in the context of the development of AI and Law, while often offering some personal reactions and reflections. As a whole, the subsections build into (...) a history of the last quarter century of the field, and provide some insights into where it has come from, where it is now, and where it might go. (shrink)

In this paper, the author examines the burden of proof in the argu- mentative confrontations taking part in practices of political accountability. She does so by explaining how politicians maneuver strategically with the burden of proof in an attempt at winning the discussion in which they are involved. After making clear the role of the burden of proof in defining the difference of opinion in argumentative confrontations, the author outlines the constraints imposed by practices of political accountability on the burden (...) of proof. Finally, she analyzes in detail a concrete case in which a politician maneuvers in such a way that his burden of proof is significantly diminished. (shrink)

This paper aims to contribute to an understanding of the politicians’ burden of proof in political interviews by explaining how politicians attempt to delimit the burden of proof which they acquire for their standpoints in response to criticism. As politicians always want to give a positive evaluation of their activities, they respond to the critics by delimiting their burden of proof in such a way that their standpoints are easy to defend. The research question to be answered is: How do (...) politicians expediently delimit their burden of proof in political interviews in response to criticism? First, the author characterizes political interviews as accountability practices which by virtue of their institutional traits impose limits on the politicians’ burden of proof. Second, the author explains some of the possibilities for delimiting the burden of proof in the communicative practices at issue by analyzing in detail several fragments from a political interview. (shrink)

How is the burden of proof to be distributed among individuals who are involved in resolving a particular issue? Under what conditions should the burden of proof be distributed unevenly? We distinguish attitudinal from dialectical burdens and argue that these questions should be answered differently, depending on which is in play. One has an attitudinal burden with respect to some proposition when one is required to possess sufficient evidence for it. One has a dialectical burden with respect to some proposition (...) when one is required to provide supporting arguments for it as part of a deliberative process. We show that the attitudinal burden with respect to certain propositions is unevenly distributed in some deliberative contexts, but in all of these contexts, establishing the degree of support for the proposition is merely a means to some other deliberative end, such as action guidance, or persuasion. By contrast, uneven distributions of the dialectical burden regularly further the aims of deliberation, even in contexts where the quest for truth is the sole deliberative aim, rather than merely a means to some different deliberative end. We argue that our distinction between these two burdens resolves puzzles about unevenness that have been raised in the literature. (shrink)

The informal logic movement began as an attempt to develop – and teach – an alternative logic which can account for the real life arguing that surrounds us in our daily lives – in newspapers and the popular media, political and social commentary, advertising, and interpersonal exchange. The movement was rooted in research and discussion in Canada and especially at the University of Windsor, and has become a branch of argumentation theory which intersects with related traditions and approaches (notably formal (...) logic, rhetoric and dialectics in the form of pragma-dialectics). In this volume, some of the best known contributors to the movement discuss their views and the reasoning and argument which is informal logic’s subject matter. Many themes and issues are explored in a way that will fuel the continued evolution of the field. Federico Puppo adds an insightful essay which considers the origins and development of informal logic and whether informal logicians are properly described as a “school” of thought. In considering that proposition, Puppo introduces readers to a diverse range of essays, some of them previously published, others written specifically for this volume. (shrink)

In this paper, we use concepts, structure and tools from argumentation theory to show how conversational implicatures are triggered by conflicts of presumptions. Presumptive implicatures are shown to be based on defeasible forms of inference used in conditions of lack of knowledge, including analogical reasoning, inference to the best explanation, practical reasoning, appeal to pity, and argument from cause. Such inferences are modelled as communicative strategies to knowledge gaps that shift the burden of providing the missing contrary evidence to the (...) other party in a dialogue. Through a series of illustrative examples, we show how such principles of inference are based on common knowledge about the ordinary course of events shared by participants in a structured dialogue setting in which they take turns putting forward and responding to speech acts. (shrink)

semantic minimalism and moderte contextualism.

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.

Eristic has been studied more and more intensively in recent years in philosophy, law, communication theory, logic, proof theory, and A.I. Nevertheless, the modern origins of eristic, which almost all current researchers see in the philosopher Arthur Schopenhauer, are considered to be a theory of the illegitimate use of logical and rhetorical devices. Thus, eristic seems to violate the norms of discourse ethics. In this paper, I argue that this interpretation of eristic is based on prejudices that contradict the original (...) intention of modern eristic. Eristic is not an art of being right or winning an argument, but an art of protecting oneself from the one who deliberately violates norms of discourse ethics to gain argumentative acceptance. For this reason, eristic must be seen as a discipline of Enlightenment philosophy and a correlate of discourse ethics. Especially in the age of alternative facts and post-factual politics, this makes eristic a valuable discipline. (shrink)

The interpretation and the indirect reporting of a speaker’s communicative intentions lie at the crossroad between pragmatics, argumentation theory, and forensic linguistics. Since the leading case Masson v. New Yorker Magazine, Inc., in the United States the legal problem of determining the truth of a quotation is essentially equated with the correctness of its indirect reporting, i.e. the representation of the speaker’s intentions. For this reason, indirect reports are treated as interpretations of what the speaker intends to communicate. Theoretical considerations, (...) aimed at establishing the pragmatic meaning of an utterance and differentiating between presumptive and non-presumptive interpretation, are thus interwoven with the practical legal need of distinguishing a correct indirect report from an indirect one or a misquotation. An incorrect report or a misquotation has the dialectical effect of attributing to the misquoted party commitments that he never held, which the latter needs to rebut. This shifting of the burden of persuasion can be increased by using strategically the conflict between the presumptive interpretation of an utterance and the non-presumptive one, i.e. the different types of pragmatic ambiguity. When an interpreter is confronted with an utterance taken out of its dialogical context, his interpretative process is not guided by the actual context or intention, but rather the most frequent or prototypical dialogical setting or the most typical individual purpose that it could have served to achieve. This presumptive reconstruction can be used to provide a prima facie case that the other party needs to reject. The stronger the interpretative presumptions a speaker needs to rebut, the more effective the misquotation strategy. The conflict between the systematic and the presumptive process of interpretation can be represented as an argumentative mechanism of reconstruction of the individual intention, which allows one to assess the reasonableness of the interpretative reasoning. (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.