Gilbert's kisceral argumentation is, roughly speaking, about arguing based on intuitions. In the forefront of such a (rhetorical) model are arguers and audiences, who resolve disagreements using kisceral arguments. Intuitions as reasons were more important in pre-modern law, when the law was not as explicit, precise, and determinate as today. Law influenced by religion or religious law was a typical example. In our much more secular modern era, intuitions are more or less subordinated to the (legal) logical (...) mode of arguing. However, in tough legal cases, when logic "runs out," it is values that decide them. Not surprisingly, neuroscience and cognitive psychology have shown a strong connection between values and intuition. (shrink)

Of the different modes that characterize Michael Gilbert’s multi-modal theory of argumentation, the kisceral is in many ways the most challenging to understand and employ. It appears to bypass the processes of reason that have dominated accounts in the Western tradition, diverting us toward the private worlds of hunches and gut reactions. This paper explores the nature of kisceral arguments, comparing them to the way intuition operates in William James’ examination of mystical experience. Having provided an account (...) of kisceral arguments and their operation, the discussion turns to the even more challenging issue of how such arguments should be evaluated. (shrink)

Gilbert’s four modes of communication include the logical, the emotional, the visceral and the kisceral, which last has not received much attention at all. This mode covers the forms of argument that rely on intuition and undefended basal assumptions. These forms range from the scientific and mathematical to the religious and mystical. In this paper these forms will be examined, and suggestions made for ways in which intuitive frameworks can be compared and valued.

This paper responds to two aspects of Ralph Johnson's Manifest Rationality (2000). The first is his critique of deductivism. The second is his failure to make room for some species of argument (e.g., visual and kisceral arguments) proposed by recent commentators. In the first case, Johnson holds that argumentation theorists have adopted a notion of argument which is too narrow. In the second, that they have adopted one which is too broad. I discuss the case Johnson makes for (...) both claims, and possible objections to his analysis. (shrink)

On Gilbert’s multi-modal theory of argumentation, the “logical” is but one among many modes of argument, including the emotional, the visceral (physical), and the kisceral (intuitive). Yet, I argue that, properly understood, the logical is not one mode among many. Rather, it is better understood as the _uber-mode_ of argument. What Gilbert calls the “logical mode” of argument—a linear, orderly, highly verbalizable, way of arguing—is made possible only to the extent that the logic of some space of reasons (...) has been articulated. The “anti-logical” penchant of multi-modal argumentation is not found at the object-level—in its countenancing “non-logical” modes of argument, but at the meta-level—in its resistance, as a mistaken embracing of the “logical” mode, to using the logics governing the different modes to self-regulate the course of our arguings. (shrink)

This argument explores transcultural commonalities among civic arguments from divination in global antiquity. In the ancient world, proponents engaged in kisceral arguments deriving from divinatory signs: arguments ex divinatione regarding prospective civic action. Under ideal circumstances, their aim was to help insure that the collective action of human political organizations was aligned with the natural synchrony of the cosmos. Thus, civic arguments from divination were employed to anticipate the future’s course based on the signs the system produced holistically. In (...) ancient Mesopotamia, China, and Rome, divination was employed as a tool for aligning the order of human society to that of a conception of metaphysical or cosmic order. By comparing these argumentative examples and rationales, we see a broader context for the way in which humans made arguments toward political futurity outside more conventional syllogistic formulations concerning causation. Rather, the argumentative strategies of many ancient cultures embraced an understanding of the future as the logical outcome of a holistic dynamism in kairotic time. (shrink)

The main stream of formal and informal logic as well as more recent work in discourse analysis provides a way of understanding certain arguments that particularly lend themselves to rational analysis. I argue, however, that these, and allied modes of analysis, be seen as heuristic models and not as the only proper mode of argument. This article introduces three other modes of argumen tation that emphasize distinct aspects of human communication, but that, at the same time, must be considered for (...) the full understanding of argumentation. These modes are (1) the emotional, which relates to the realm of feelings, (2) the visceral, which stems from the area of the physical, and (3) the kisceral, which covers the intuitive and non-sensory arenas. At its most extreme the view holds that arguments may be given (almost) wholly within one mode and not be at all susceptible to those methods of argument analysis previously used. A more cautious statement allows that any interactive argument will (possibly) contain elements from various modes, and that to attempt to reduce these all to the rational is prejudiced reductionism. (shrink)

In this paper I question the primacy of argumentation relying solely on logic by showing how the body and mind are deeply connected and as a result how communication and argumentation are a product of this mind/body connection. In particular, I explore the physicality of argumentation through the research and writings on gestures and the embodied mind. Michael Gilbert’s theory of multi-modal argumentation provides the general approach for this elaboration.

Michael Gilbert’s multi-modal theory of argument challenges earlier accounts of arguing assumed in formal and informal logic. His account of emotional, visceral, and kisceral modes of arguing rejects the assumption that all arguments must be treated as instances of one “logical mode.” This paper compares his alternative modes to other modes proposed by those who have argued for visual, auditory, and other “multimodal” modes of arguing. I conclude that multi-modal and multimodal (without the hyphen) modes are complementary. Collectively, they (...) represent an important attempt to radically expand the scope of informal logic and the argumentation that it studies. (shrink)

My essay, “Multi-modal argumentation” was published in the journal, _Philosophy of the Social Sciences,_ in 1994. This information appeared again in my book, _Coalescent argumentation_ in 1997. In the ensuing twenty years, there have been many changes in argumentation theory, and I would like to take this opportunity to examine my now middle-aged theory in light of the developments in our discipline. I will begin by relating how a once keen intended lawyer and then formal logician ended up (...) in argumentation theory. (If you do not care to read this bit of autobiography, skip to Section 2). (shrink)

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)

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)

This book concentrates on argumentation as it emerges in ordinary discourse, whether the discourse is institutionalized or strictly informal. Crucial concepts from the theory of argumentation are systematically discussed and explained with the help of examples from real-life discourse and texts. The basic principles are explained that are instrumental in the analysis and evaluation of argumentative discourse. Methodical instruments are offered for identifying differences of opinion, analyzing and evaluating argumentation and presenting arguments in oral and written discourse. (...) In addition, the book provides a great variety of exercises and assignments to improve the students' skill in presenting argumentation. The authors begin their treatment of argumentation theory at the same juncture where argumentation also starts in practice: The difference of opinion that occasions the evolvement of the argumentation. Each chapter begins with a short summary of the essentials and ends with a number of exercises that students can use to master the material. _Argumentation_ is the first introductory textbook of this kind. It is intended as a general introduction for students who are interested in a proper conduct of argumentative discourse. Suggestions for further reading are made for each topic and several extra assignments are added to the exercises. Special features: * A concise and complete treatment of both the theoretical backgrounds and the practice of argumentation analysis and evaluation. * Crucial concepts from pragmatics presented in a non-technical way; introducing the theory of verbal communication. * Unique coverage of both oral and written presentation of arguments. * Exercises and assignments based on real-life texts from a variety of contexts. (shrink)

This book identifies 25 argumentation schemes for presumptive reasoning and matches a set of critical questions to each.

The high prevalence of brain injury incidents in adolescence and adulthood demands effective models for re-learning lost cognitive abilities. Impairment in brain injury survivors’ higher-level cognitive functions is common and a negative predictor for long-term outcome. We conducted two small-scale interventions (N = 12; 33.33% female) with persons with acquired brain injuries in two municipalities in Sweden. Age ranged from 17 to 65 years (M = 51.17, SD = 14.53). The interventions were dialogic, inquiry-based, and inspired by the Philosophy for (...) Children Programme, a participatory thinking skills approach with documented higher-order cognitive outcomes, such as developed argumentation skills, in other target groups. Philosophical dialogues were conducted once a week in the two groups, totalling 12 dialogues per group. Group argumentation development was measured through compared scores from structured observations of filmed dialogues early and late in the intervention. Large positive changes in mean scores from early to late in the intervention, together with constantly high facilitator quality, suggest argumentation development in the sample due to the intervention. (shrink)

This article studies argumentation for acceptability of corporate environmental actions in corporate environmental statements, with emphasis on stakeholder relations and environmental values. Stakeholder theory is commonly taken as the basis for corporate environmental management, and rhetoric typical of the stakeholder approach dominates the field. Although environmental issues are strongly charged with values, the dominant stakeholder approach does not stress the value dimension. The data of the study consists of environmental statements by Finnish forerunning business corporations in the forefront of (...) corporate environmental responsibility. The results of the study indicate that the statements argue for the acceptability of corporate environmental actions through three power-related rhetorical forms that are competing ways to produce acceptability in the data: dominance, subordination and equality, and joint action. Each rhetorical form describes a power-based relationship between stakeholders and the corporation and leans on a specific value type producing legitimacy for that rhetoric form. (shrink)

The book offers a compact but comprehensive introductory overview of the crucial components of argumentation theory. In presenting this overview, argumentation is consistently approached from a pragma-dialectical perspective by viewing it pragmatically as a goal-directed communicative activity and dialectically as part of a regulated critical exchange aimed at resolving a difference of opinion. As a result, the book also systematically explains how the constitutive parts of the pragma-dialectical theory of argumentation, which are discussed in a number of (...) separate publications, hang together. The following crucial topics are discussed: argumentation theory as a discipline; the meta-theoretical principles of pragma-dialectics; the model of a critical discussion aimed at resolving a difference of opinion; fallacies as violations of a code of conduct for reasonable argumentative discourse; descriptive research of argumentative reality; analysis as theoretically-motivated reconstruction; strategic manoeuvring aimed at combining achieving effectiveness with maintaining reasonableness; the conventionalization of argumentative practices; prototypical argumentative patterns; pragma-dialectics amidst other approaches. Argumentation Theory: A Pragma-Dialectical Perspective is clearly written and makes argumentation theory understandable to all scholars and advanced students interested in argumentation research. (shrink)

This book analyzes the uses of emotive language and redefinitions from pragmatic, dialectical, epistemic and rhetorical perspectives, investigating the relationship between emotions, persuasion and meaning, and focusing on the implicit dimension of the use of a word and its dialectical effects. It offers a method for evaluating the persuasive and manipulative uses of emotive language in ordinary and political discourse. Through the analysis of political speeches and legal arguments, the book offers a systematic study of emotive language in argumentation, (...) rhetoric, communication, political science and public speaking. (shrink)

In this paper we attempt to identify which peer collaboration characteristics may be accountable for conceptual change through interaction. We focus on different socio‐cognitive aspects of the peer dialog and relate these with learning gains on the dyadic as well as the individual level. The scientific topic that was used for this study concerns natural selection, a topic for which students’ intuitive conceptions have been shown to be particularly robust. Learning tasks were designed according to the socio‐cognitive conflict instructional paradigm. (...) After receiving a short instructional intervention on natural selection, paired students were asked to collaboratively construct explanations for certain evolutionary phenomena while engaging in dialectical argumentation. Two quantitative coding schemes were developed, each with a different granularity. The first assessed discrete dialog moves that pertained to dialectical argumentation and to consensual explanation development. The second scheme characterized the dialog as a whole on a number of socio‐cognitive dimensions. Results from analyses on the dyadic as well as the individual level revealed that the engagement in dialectical argumentation predicted conceptual learning gains, whereas consensual explanation development did not. These findings open up new venues for research on the mechanisms of learning in and from peer collaboration. (shrink)

argumentation has been shown to be a powerful tool within many fields such as artificial intelligence, logic and legal reasoning. In this paper we enhance Dung’s well-known abstract argumentation framework with explanatory capabilities. We show that an explanatory argumentation framework (EAF) obtained in this way is a useful tool for the modeling of scientific debates. On the one hand, EAFs allow for the representation of explanatory and justificatory arguments constituting rivaling scientific views. On the other hand, different (...) procedures for selecting arguments, corresponding to different methodological and epistemic requirements of theory evaluation, can be formulated in view of our framework. (shrink)

There is a generic way to add any new feature to a system. It involves identifying the basic units which build up the system and introducing the new feature to each of these basic units. In the case where the system is argumentation and the feature is probabilistic we have the following. The basic units are: the nature of the arguments involved; the membership relation in the set S of arguments; the attack relation; and the choice of extensions. Generically (...) to add a new aspect to an argumentation network \ can be done by adding this feature to each component. This is a brute-force method and may yield a non-intuitive or meaningful result. A better way is to meaningfully translate the object system into another target system which does have the aspect required and then let the target system endow the aspect on the initial system. In our case we translate argumentation into classical propositional logic and get probabilistic argumentation from the translation. Of course what we get depends on how we translate. In fact, in this paper we introduce probabilistic semantics to abstract argumentation theory based on the equational approach to argumentation networks. We then compare our semantics with existing proposals in the literature including the approaches by M. Thimm and by A. Hunter. Our methodology in general is discussed in the conclusion. (shrink)

Robert Alexy develops his influential theory of legal reasoning exploring the nature of legal argumentation and its relation to practical reasoning. In doing so he sheds light on fundamental questions of law and rationality, which are as crucial to practising lawyers and law students as they are to scholars of legal theory.

An argumentation profile is defined as a methodological instrument for analyzing argumentative discourse considering distinct and interrelated dimensions: the types of argument used, their quality, and the emotions triggered. Walton’s theoretical contributions are developed as a coherent analytical and multifaceted toolbox for capturing these aspects. Argumentation schemes are used to detect and quantify the types of argument. Fallacy analysis and the assessment of the implicit premises retrieved through the schemes allow evaluating arguments. Finally, the frequency of emotive words (...) signals the most common emotions aroused. This method is illustrated through a corpus of argumentative tweets of three politicians. (shrink)

In this paper, it is explained that a dialogical approach to complex argumentation can be fruitful for solving two important problems concerning the analysis of the argumentation structure. First, such an approach makes it possible to clarify the distinction between coordinative and multiple argumentation structures, and to identify clues in the presentation for each of these structures. Second, a dialogical approach can provide a basis for dealing more adequately with refutations of counterarguments.

There are distinct but legitimate notions of both personal justification and interpersonal justification. Interpersonal justification is definable in terms of personal justification. A connection is established between good argumentation and interpersonal justification.

In this paper, I explore the relationship of virtue, argumentation, and philosophical conduct by considering the role of the specific virtue of intellectual humility in the practice of philosophical argumentation. I have three aims: first, to sketch an account of this virtue; second, to argue that it can be cultivated by engaging in argumentation with others; and third, to problematize this claim by drawing upon recent data from social psychology. My claim is that philosophical argumentation can (...) be conducive to the cultivation of virtues, including humility, but only if it is conceived and practiced in appropriately ‘edifying’ ways. (shrink)

The study presented here examines how interacting with a more capable interlocutor influences use of argumentation strategies in electronic discourse. To address this question, 54 young adolescents participating in an intervention centered on electronic peer dialogs were randomly assigned to either an experimental or control condition. In both conditions, pairs who held the same position on a social issue engaged in a series of electronic dialogs with pairs who held an opposing position. In the experimental condition, in some dialogs, (...) unbeknownst to them (because dialog took place electronically), the opponent was a more capable (“expert”) adult. Dialogs in the control condition were only with peers. Argumentation strategies of the experimental group who argued with the “expert” showed immediate strategy improvements in their subsequent peer dialogs, improvement absent in the control group (Cohen's d = 1.12). In particular, the experimental group showed greater use of counterargument in general and advanced forms of counterargument (undermining) that challenges the deeper premises or reasoning on which an argument is based. Implications with respect to mechanisms of change in the development of argumentation skills are considered. (shrink)

The Pyrrhonist’s argumentative practice is characterized by at least four features. First, he makes a therapeutic use of arguments: he employs arguments that differ in their persuasiveness in order to cure his dogmatic patients of the distinct degrees of conceit and rashness that afflict them. Secondly, his arguments are for the most part dialectical: when offering an argument to oppose it to another argument advanced by a given dogmatist, he accepts in propria persona neither the truth of its premises and (...) conclusion nor the validity of its logical form. Thirdly, he avails himself of arguments in his own open-minded inquiry into the truth about a wide range of topics. Fourthly, Pyrrhonian argumentation is oppositional inasmuch as it typically works by producing oppositions among arguments that appear to the Pyrrhonist to be equipollent. In this article, I focus on the first three features with the aim of both shedding some light on them and determining whether they are in tension or coherently relate to each other. (shrink)

Robert Alexy develops his influential theory of legal reasoning exploring the nature of legal argumentation and its relation to practical reasoning. In doing so he sheds light on fundamental questions of law and rationality, which are as crucial to practising lawyers and law students as they are to scholars of legal theory.

The detection of hate speech and fake news in political discourse is at the same time a crucial necessity for democratic societies and a challenge for several areas of study. However, most of the studies have focused on what is explicitly stated: false article information, language that expresses hatred, derogatory expressions. This paper argues that the explicit dimension of manipulation is only one – and the least problematic – of the risks of political discourse. The language of the unsaid is (...) much more dangerous and incomparably more difficult to detect, hidden in different types of fallacies and inappropriate uses of emotive language. Through a threefold coding scheme based on the instruments of argumentation theory and pragmatics, a corpus of argumentative tweets published by 4 politicians (Matteo Salvini, Donald Trump, Jair Bolsonaro, and Joseph Biden) within 6 months from their taking office (corresponding to the official end of their election campaign) is analyzed, detecting the types of argument, the fallacies, and the uses and misuses of “emotive words.” This coding results in the argumentation profiles of the speakers, which are compared statistically to show their different implicit strategies and deceptive tactics. (shrink)

This article deals with the relationship between argumentation and persuasion. It defends the idea that these two concepts are not as opposed as all too often said. If it is important to recognize their differences (there are argumentative discourses without persuasion and persuasive discourses without argumentation), there is nevertheless an overlap, in which characteristics are taken from both. We propose to call this overlap “persuasive argumentation”. In order to bridge argumentation and persuasion, we will first distinguish (...) the latter from manipulation. In the second part of this article, we will analyze four cases of persuasive argumentation: the enthymeme, a few rhetorical figures, narration and visual argumentation. (shrink)

The present study examined how the pre-war debate of the US decision to invade Iraq (in March 2003) was discursively constructed in the US/British mainstream newspaper opinion/editorial (op/ed) argumentation. Drawing on theoretical insights from critical discourse analysis and argumentation theory, I problematised the fallacious discussion used in the pro-war op/eds to build up a ‘moral/legal case’ for war on Iraq based on adversarial (rather than dialogical) argumentation. The proponents of war deployed ‘instrumental rationality’ (ends-justify-means reasoning), ‘ethical necessity’ (...) (Bush’s ‘Preemption Doctrine’) and ‘humanitarian virtue’ (the bombing of Iraq to ‘save’ Iraqis from Saddam’s pestilent tyranny) to justify the pending invasion of Iraq. Their arguments intertextually resonated with Bush administration’s ‘war on terror’ rhetoric in a way that created a form of indexical association through ‘recontextualisation’. The type of arguments marshalled by the pro-war op/ed commentators uncritically bolstered the set of US official ‘truth claims’ and ‘presuppositions’. (shrink)

This essay begins with a critique of the Critical-Logical model dominant in contemporary argumentation theory. The concerns raised stem primarily from considerations brought by several feminist thinkers including Carol Gilligan, Karen Warren, Deborah Tannen and, most especially, Andrea Nye. It is argued that, in light of these considerations, and concerns of essentialism or non-essentialism notwithstanding, that the Critical-Logical model is liable to dis-enfranchise a significant part of the population with regard to modes and styles of reasoning. The solution is (...) found in coalescent reasoning, an approach to argumentation that focuses on finding agreement rather than emphasizing disagreement and criticism. (shrink)

Innerhalb verschiedener Arten der Argumentation für die Existenz Gottes gibt es auch eine, in der folgende Disjunktion zum Ausgangspunkt gesetzt wird: 1) entweder existiert kein unabhängiges Seiendes oder 2) das unabhängige Seiende existiert. Diese Disjunktion ist vollständig. Es genügt also, ihren ersten Teil zu falsifizieren, der impliziert, dass nur das abhängige Seiende existiert, damit sich der zweite als wahr erweist. Der Weg der Falsifikation des ersten Teils der Disjunktion bestünde hingegen in der Entscheidung zwischen den Gliedern folgender Disjunktion: a) (...) entweder bedarf die bedingte Wirklichkeit einer endlichen Anzahl von Bedingungen, oder b) sie bedarf einer unendlichen Anzahl von Bedingungen. (shrink)

This article shows that the Rhodian model of metatheory can be successfully applied to nonformal systems of a methodological rather than an axiological nature if the demands of the model are satisfied. This requires that we take into account the possible variations of Rhodian models of argumentation and choose the most effective of them. Plato's model of meta-argumentation is only applicable to fields of argumentation that are completely formalized and could be presented as whole general theories.

Using print ads and recognizing the role of visual images in argument (Groarke) and the presence of arguments in ads (Slade), this paper argues that the work of argumentation theorists from Aristotle to van Eemeren and Grootendorst can be used to support the thesis that ads are arguments. I cite as evidence definitions, demarcations, delineations, and descriptions of argument put forth by leading scholars in the field of argumentation. This includes Aristotle, Informal Logic, Toulmin (Claim, Data, Warrant, Backing, (...) Qualifier, Rebuttal), Johnson and Blair (argument as “reasons or evidence as grounds or support for an opinion”), Gilbert (Multi-Modal Argumentation), and van Eemeren and Grootendorst (argumentation as a social activity and pragma-dialectics). I show how, although just fitting a particular advertisement to someone’s definition does not mean that all ads are arguments, nevertheless, the fact that we can find in an ad all these elements from this variety of scholars over time, leaves us reasonably secure in stating that an ad is indeed an argument. Since my argument would be the same for practically any ad, I am using only one ad. I do, however, use the kind of ad that is least likely to seem to be an argument: an ad with few words, an ad which is mostly visual. If I can show how even an almost entirely visual ad can be analyzed as an argument using the terms of all these scholars of argumentation, I will maintain that most ads could be analyzed in the same way. (shrink)

The Handbook of Formal Argumentation is a community effort aimed at providing a comprehensive and up-to-date view of the state of the art and current trends in the lively research field of formal argumentation. The first volume of the Handbook is organised into five parts, containing nineteen chapters in all, each written by leading experts in the field. The first part provides a general and historical perspective on the field. The second part gives a comprehensive coverage of the (...) argumentation formalisms available in the literature at various levels of abstraction. The third part is devoted to cover some of the many dialogical aspects of argumentation, while the fourth one deals with algorithmic, computational and implementation issues. Finally, the fifth part provides some deeper analyses on the previously introduced topics. The Handbook of Formal Argumentation is an open-ended initiative of which the present volume is the first outcome. Further volumes are planned to cover topics not included in the present one and the initiative is conceived to grow by the support and feeding it receives from the community members. (shrink)

This paper demonstrates how argumentation schemes can be used in decision support systems that help clinicians in making treatment decisions. The work builds on the use of computational argumentation, a rigorous approach to reasoning with complex data that places strong emphasis on being able to justify and explain the decisions that are recommended. The main contribution of the paper is to present a novel set of specialised argumentation schemes that can be used in the context of a (...) clinical decision support system to assist in reasoning about what treatments to offer. These schemes provide a mechanism for capturing clinical reasoning in such a way that it can be handled by the formal reasoning mechanisms of formal argumentation. The paper describes how the integration between argumentation schemes and formal argumentation may be carried out, sketches how this is achieved by an implementation that we have created and illustrates the overall process on a small set of case studies. (shrink)

A broad assumption in argumentation theory is that argumentation primarily regards resolving, confronting, or managing disagreement. This assumption is so fundamental that even when there does not appear to be any real disagreement, the disagreement is suggested to be present at some other level. Some have questioned this assumption (most prominently, Perelman and Olbrechts-Tyteca, and Doury), but most are reluctant to give up on the key idea that persuasion, the core of argumentation theory, can only regard disagreements. (...) We argue here that this assumption is false. Argument may be as much about strengthening or maintaining agreement as it is about disagreement. Once we see how argument is possible and manifestly enacted under conditions of agreement, then we have tools to explain otherwise curious fallacies and argumentative phenomena. (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)