Abstract argumentation and explanation applied to scientific debates

Abstract 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.     

Two approaches to the problems of self-attacking arguments and general odd-length cycles of attack

The problems that arise from the presence of self-attacking arguments and odd-length cycles of attack within argumentation frameworks are widely recognized in the literature on defeasible argumentation. This paper introduces two simple semantics to capture different intuitions about what kinds of arguments should become justified in such scenarios. These semantics are modeled upon two extensions of argumentation frameworks, which we call sustainable and tolerant. Each one is constructed on the common ground of the powerful concept of admissibility introduced by Dung in [P.M. Dung, On the acceptability of arguments and its fundamental role in non-monotonic reasoning, logic programming, and n-person games, Artificial Intelligence 77 (1995) 321–357]. The novelty of this approach consists in viewing the admissibility of a subset of arguments as relative to potentially challenging subsets of arguments. Both sustainable and tolerant semantics are more credulous than preferred semantics (i.e. they justify at least the same arguments, and possibly more). Given certain sufficient conditions they coincide among them as well as with other semantics introduced by Dung.     

Reflective Argumentation: A Cognitive Function of Arguing

Why do we formulate arguments? Usually, things such as persuading opponents, finding consensus, and justifying knowledge are listed as functions of arguments. But arguments can also be used to stimulate reflection on one’s own reasoning. Since this cognitive function of arguments should be important to improve the quality of people’s arguments and reasoning, for learning processes, for coping with “wicked problems,” and for the resolution of conflicts, it deserves to be studied in its own right. This contribution develops first steps towards a theory of reflective argumentation. It provides a definition of reflective argumentation, justifies its importance, delineates it from other cognitive functions of argumentation in a new classification of argument functions, and it discusses how reflection on one’s own reasoning can be stimulated by arguments.     

Argumentation and Fallacy in the Justification of the 2003 War on Iraq

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’.     

What Students’ Arguments Can Tell Us: Using Argumentation Schemes in Science Education

The relationship between teaching and argumentation is becoming a crucial issue in the field of education and, in particular, science education. Teaching has been analyzed as a dialogue aimed at persuading the interlocutors, introducing a conceptual change that needs to be grounded on the audience’s background knowledge. This paper addresses this issue from a perspective of argumentation studies. Our claim is that argumentation schemes, namely abstract patterns of argument, can be an instrument for reconstructing the tacit premises in students’ argumentative reasoning and retrieving the background beliefs that are the basis of their arguments. On this perspective, the process of premise reconstruction is followed by a heuristic reasoning process aimed at discovering the students’ previous intuitions that can explain the premises and concepts that are left unexpressed in their arguments. The theoretical insights advanced in this paper are illustrated through selected examples taken from activities concerning predictive claims on scientific issues.     

Evaluating Arguments Based on Toulmin’s Scheme

Toulmin’s scheme for the layout of arguments (1958, The Uses of Argument, Cambridge University Press, Cambridge) represents an influential tool for the analysis of arguments. The scheme enriches the traditional premises-conclusion model of arguments by distinguishing additional elements, like warrant, backing and rebuttal. The present paper contains a formal elaboration of Toulmin’s scheme, and extends it with a treatment of the formal evaluation of Toulmin-style arguments, which Toulmin did not discuss at all. Arguments are evaluated in terms of a so-called dialectical interpretation of their assumptions. In such an interpretation, an argument’s assumptions can be evaluated as defeated, e.g., when there is a defeating reason against the assumption. The present work builds on recent research on defeasible argumentation (cf. e.g. the work of Pollock, Reiter, Loui, Vreeswijk, Prakken, Hage and Dung). More specifically, the author’s work on the dialectical logic DEFLOG and the argumentation tool ARGUMED serve as starting points.     

A QBF-based formalization of abstract argumentation semantics

We introduce a unified logical theory, based on signed theories and Quantified Boolean Formulas (QBFs) that can serve as the basis for representing and computing various argumentation-based decision problems. It is shown that within our framework we are able to model, in a simple and modular way, a wide range of semantics for abstract argumentation theory. This includes complete, grounded, preferred, stable, semi-stable, stage, ideal and eager semantics. Furthermore, our approach is purely logical, making for instance decision problems like skeptical and credulous acceptance of arguments simply a matter of entailment and satisfiability checking. The latter may be verified by off-the-shelf QBF-solvers.     

The Rational Reconstruction of Argumentation Referring to Consequences and Purposes in the Application of Legal Rules: A Pragma-Dialectical Perspective

In this paper, the author develops an instrument for the rational reconstruction of argumentation in which a judicial decision is justified by referring to the consequences in relation to the purpose of the rule. The instrument is developed by integrating insights from legal theory and legal philosophy about the function and use of arguments from consequences in relation to the purpose of a rule into a pragma-dialectical framework. Then, by applying the instrument to the analysis of examples from legal practice, it is demonstrated that the instrument can offer a heuristic and critical tool for the analysis and evaluation of legal argumentation that can ‘bridge’ the gap between more abstract discussions of forms of legal argumentation on the one hand, and legal arguments as they occur in actual legal practice on the other hand.     

From Theory of Rhetoric to the Practice of Language Use: The Case of Appeals to Ethos Elements

In their book Commitment in Dialogue, Walton and Krabbe claim that formal dialogue systems for conversational argumentation are “not very realistic and not easy to apply”. This difficulty may make argumentation theory less well adapted to be employed to describe or analyse actual argumentation practice. On the other hand, the empirical study of real-life arguments may miss or ignore insights of more than the two millennia of the development of philosophy of language, rhetoric, and argumentation theory. In this paper, we propose a novel methodology for adapting such theories to serve as applicable tools in the study of argumentation phenomena. Our approach is both theoretically-informed and empirically-grounded in large-scale corpus analysis. The area of interest are appeals to ethos, the character of the speaker, building upon Aristotle’s rhetoric. Ethotic techniques are used to influence the hearers through the communication, where speakers might establish, but also emphasise, weaken or undermine their own or others’ credibility and trustworthiness. Specifically, we apply our method to Aristotelian theory of ethos elements which identifies practical wisdom, moral virtue and goodwill as components of speakers’ character, which can be supported or attacked. The challenges we identified in this case and the solutions we proposed allow us to formulate general guidelines of how to exploit rich theoretical frameworks to the analysis of the practice of language use.

     

Evaluating dialectical structures with Bayesian methods

This paper shows how complex argumentation, analyzed as dialectical structures, can be evaluated within a Bayesian framework by interpreting them as coherence constraints on subjective degrees of belief. A dialectical structure is a set of arguments (premiss-conclusion structure) among which support- and attack-relations hold. This approach addresses the observation that some theses in a debate can be better justified than others and thus fixes a shortcoming of a theory of defeasible reasoning which applies the bivalence principle to argument evaluations by assigning them the status of being either defeated or undefeated. Evaluation procedures which are based on the principle of bivalence can, however, be embedded as a special case within the Bayesian framework. The approach developed in this paper rests on the assumptions that arguments can be reconstructed as deductively valid and that complex argumentation can be reconstructed such that premisses of arguments with equivalent conclusions are pairwise independent.     

A Defense of Conduction: A Reply to Adler

In (2013) Jonathan Adler argued that conductive arguments, as they are commonly characterized, are impossible—that no such argument can exist. This striking contention threatens to undermine a topic of argumentation theory originated by Trudy Govier (1979) based on Carl Wellman (1971) and revisited by the papers in “Conductive argument, An overlooked type of defeasible reasoning” (ed. Blair and Johnson, 2011). I here argue that Adler’s dismissal of conductive arguments relies on a misreading of the term ‘non-conclusive’ used in the characterization of this type of reasoning and argument, and that as a result, his refutation fails. However, Adler’s critique raises other questions about conductive arguments that have to be answered.     

A New Science of Criticism

John R. Searle has recently observed that something might instantiate a Chinese‐‘understanding’ computer program without having any understanding of Chinese. He thinks that this implies that instantiating such a program is ‘never by itself a sufficient condition of intentionality’. I show that this phrase is incoherent, and that all that follows is that instantiating such a program is not in every case a sufficient condition for the given intentionality. But the conclusion to Searle's argument, thus revised, is neither new nor significant; Searle's arguments merely raise old issues in new clothing.     

The Cultural Embeddedness of Arguments Raised as a Part of the Bulgarian Debate About the Ratification of the Istanbul Convention

The paper presents an analysis of the cultural embeddedness of arguments, raised as a part of the Bulgarian debate about the ratification of the Istanbul convention. The method I employed was the localization procedure of Generalized Argumentation theory. Through a qualitative analysis of empirical argumentation data, I identified arguments in favour of or against the ratification of the Istanbul convention. Information about the cultural background against which these arguments were raised, i.e. about Bulgarian culture, was gathered from the part of the ninth wave of the European Social Survey that used the Portrait Value Questionnaire—an instrument for measuring human values, based on Schwartz’s theory of human values. By establishing a certain relationship between the arguments and the cultural background information, I came to the conclusion that the debate between the proponents and the opponents of the ratification represented a conflict between the basic values of universalism and tradition, and more particularly, between the lower-order values of equality and respect for tradition.

     

Are Fallacies Vices?

Why are some arguments fallacious? Since argumentation is an intellectual activity that can be performed better or worse, do we evaluate arguments simply in terms of their content, or does it also make sense to evaluate the arguer in light of the content put forward? From a ‘virtue’ approach, I propose understanding fallacies as having some link with intellectual vice(s). Drawing from recent work by Paul Grice, Linda Zagzebski, Andrew Aberdein, and Douglas Walton, this essay argues that if there is some sense of argumentation where an argument is (1) truth-propagating and not (2) put forward in order to ‘win’, fallacies may be the vicious element in arguments that undermines (1), most often because the arguer’s goal is only (2). From this perspective, fallacies may not only be improper ‘moves’ in an argument, but may also reveal something lacking in the arguer’s intellectual character.     

On Some Aristotelian Sources of Modern Argumentation Theory

Although he does not provide a general analysis of argumentation, Aristotle is a highly influential source of modern argumentation theory. In his treatises the Topics, the Sophistical Refutations and the Rhetoric, Aristotle presents complementary aspects of a theory of sound arguments that are seen as the most effective means of persuasion. Aristotle’s central notion of a deductive argument (sullogismos) does not include references to an addressee, the situative context or non-verbal aspects of communication, and thus differs from some modern views on argumentation. A deductive argument in the Aristotelian sense is a sequence of intellectual steps where the conclusion follows of necessity from the premises. Aristotle does not relativize or relax this notion but takes other factors into account by providing supplementary theoretical elements. For example, he reflects on acceptable premises (endoxa), the adjustment of rhetorical arguments to the horizon of the audience, methods of finding premises on the basis of argumentative schemes (topoi), the use of non-argumentative means of persuasion, and a framework of implicit discourse rules. Many of these themes are, albeit under a different name, still discussed in modern argumentation theory.     

Judging the plausibility of arguments in scientific texts: a student–scientist comparison

The ability to evaluate scientific claims and evidence is an important aspect of scientific literacy and requires various epistemic competences. Readers spontaneously validate presented information against their knowledge and beliefs but differ in their ability to strategically evaluate the soundness of informal arguments. The present research investigated how students of psychology, compared to scientists working in psychology, evaluate informal arguments. Using a think-aloud procedure, we identified the specific strategies students and scientists apply when judging the plausibility of arguments and classifying common argumentation fallacies. Results indicate that students, compared to scientists, have difficulties forming these judgements and base them on intuition and opinion rather than the internal consistency of arguments. Our findings are discussed using the mental model theory framework. Although introductory students validate scientific information against their knowledge and beliefs, their judgements are often erroneous, in part because their use of strategy is immature. Implications for systematic trainings of epistemic competences are discussed.     

Coping with ambiguity and uncertainty in patient-physician relationships: II.Traditio argumentum respectus

A methodology of argumentation and a perspective of incredulity are essential ingredients of all intellectual endeavor, including that associated with the art and science of medical care.Traditio argumentum respectus (tradition of respectful argumentation) as a principled system of assessing the validity of beliefs, opinions, perceptions, data, and knowledge, is worthy of practice and perpetuation, because assessments of validity are susceptible to incompleteness, incorrectness, and misinterpretation. Since the latter may lead to ambiguity, uncertainty, anxiety, and animosity among the individuals (patients and physicians) involved in such dialogue, objective analyses and criteria are desirable. A tradition of respectful argumentation is a means to this end—to maximize objectivity and minimize subjectivity as part of decision-making processes and to preserve the integrity of the participants in a patient-physician relationship. During such discourse one must always be cognizant of fallacious arguments—material, verbal, and formal fallacies—since they compromise the validity of assertions. This essay summarizes a classification of fallacious arguments, by definition and by example, predicated upon the intellectual tradition of Occidental Society; and advocates a tradition of respectful argumentation to nullify them.     

Epistemic Normativity, Argumentation, and Fallacies

In Biro and Siegel (1992) we argued that a theory of argumentation mustfully engage the normativity of judgments about arguments, and we developedsuch a theory. In this paper we further develop and defend our theory.