Fabrizio Macagno

In this paper, we present a survey of the development of the technique of argument diagramming covering not only the fields in which it originated - informal logic, argumentation theory, evidence law and legal reasoning – but also more recent work in applying and developing it in computer science and artificial intelligence. Beginning with a simple example of an everyday argument, we present an analysis of it visualised as an argument diagram constructed using a software tool. In the context of a brief history of the development of diagramming, it is then shown how argument diagrams have been used to analyze and work with argumentation in law, philosophy and artificial intelligence.

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

Reasoning from negative evidence takes place where an expected outcome is tested for, and when it is not found, a conclusion is drawn based on the significance of the failure to find it. By using Gricean maxims and implicatures, we show how a set of alternatives, which we call a paradigm, provides the deep inferential structure on which reasoning from lack of evidence is based. We show that the strength of reasoning from negative evidence depends on how the arguer defines his conclusion and what he considers to be in the paradigm of negated alternatives. If we negate only two of the several possible alternatives, even if they are the most probable, the conclusion will be weak. However, if we deny all possible alternatives, the reasoning will be strong, and even in some cases deductively valid.

Argumentation schemes can be described as abstract structures representing the most generic types of argument, constituting the building blocks of the ones used in everyday reasoning. This paper investigates the structure, classification, and uses of such schemes. Three goals are pursued: 1) to describe the schemes, showing how they evolved and how they have been classified in the traditional and the modern theories; 2) to propose a method for classifying them based on ancient and modern developments; and 3) to outline and show how schemes can be used to describe and analyze or produce real arguments. To this purpose, we will build on the traditional distinctions for building a dichotomic classification of schemes, and we will advance a modular approach to argument analysis, in which different argumentation schemes are combined together in order to represent each step of reasoning on which a complex argument relies. Finally, we will show how schemes are applied to formal systems, focusing on their applications to Artificial Intelligence, AI & Law, argument mining, and formal ontologies.

The logic of academic writing is the argumentative strategy on which our papers, our sections, and our paragraphs are based. It is a strategy, as it is a plan that connects different steps and has a specific goal, namely convincing the audience of an original and important idea. And it is argumentative, for two reasons. First, we can defend our idea and we can convince our audience only through arguments, which only in very few disciplines are formal deductions. In most cases, the arguments that we use are based on premises accepted by a community and the conclusions are drawn from principles that in the ancient dialectics were called “maxims,” principles shared by everyone. Second, a paper is a dialogue between the author and his or her readers. An idea can be considered as interesting and worth reading only when it addresses a topic that is perceived as important by the readers and tackles a problem that is open and needs to be solved. Our arguments are acceptable when they start from the premises of our community of readers, avoiding repeating what is obvious for them or taking for granted what is obscure or unknown to them. In this book, we present the argumentative approach to academic writing that we used in classroom. What characterizes it and makes it unique is the perspective that is adopted. We do not start from preexisting ideas that only need to be presented in a way that is suitable to an academic public. We intend to show that writing academically is a consequence of thinking academically, or rather “strategically.” We want to explain how the linguistic and presentational devices are the result of a much deeper plan underlying them, and how mastering the logic of a paper leads to understanding and even developing academic styles. The logic of academic writing is not aimed at teaching how to use language and write texts academically, but at enabling readers to create their own style based on their own argumentative strategies.

This paper analyzes selected examples of uses of argumentation tactics that exploit emotive language, many of them criticized as deceptive and even fallacious by classical and recent sources, including current informal logic textbooks. The analysis is based on six argumentation schemes, and an account of the dialectical setting in which these schemes are used. The three conclusions are (1) that such uses of emotive language are often reasonable and necessary in argumentation based on values, (2) but that they are defeasible, and hence need to be seen as open to critical questioning (3) and that when they are used fallaciously, it is because they interfere with critical questioning or conceal the need for it. The analysis furnishes criteria for distinguishing between arguments based on the use of emotive words that are reasonable tools of persuasion, and those that are fallacious tactics used to conceal and distort information.

In the literature, the pragmatic dimension of metaphors has been clearly acknowledged. Metaphors are regarded as having different possible uses, especially pursuing persuasion. However, an analysis of the specific conversational purposes that they can be aimed at achieving in a dialogue and their adequacy thereto is still missing. In this chapter, we will address this issue focusing on the classical distinction between the explanatory and persuasive uses of metaphors, which is, however, complex to draw at an analytical level and often blurred and controversial also from a theoretical point of view. Building on the analysis of explanation in different theories and fields of study, we show how it can be conceived as characterized by a cognitive and a pragmatic dimension, where the transference of understanding is used pragmatically for different dialogical goals - such as informing, making a joint decision, and most importantly persuading. In this sense, the cognitive effects of understanding are not incompatible with a persuasive dialogical purpose. This theoretical proposal will be applied to examples drawn from the medical context, to show how a pragmatic approach to explanation can account for the complexity of the cases that can be found in actual dialogical contexts.

The purpose of this chapter is twofold. On the one hand, our goal is theoretical, as we aim at providing an instrument for detecting, analyzing, and solving ambiguities based on the reasoning mechanism underlying interpretation. To this purpose, combining the insights from pragmatics and argumentation theory, we represent the background assumptions driving an interpretation as presumptions. Presumptions are then investigated as the backbone of the argumentative reasoning that is used to assess and solve ambiguities and drive (theoretically) interpretive mechanisms. On the other hand, our goal is practical. By analyzing ambiguities as stemming from different presumptions concerning language or, more importantly, expected communicative roles and goals, we can use communicative misunderstandings as the signal of deeper disagreements concerning mutual expectations or cultural differences. This argumentation-based interpretive mechanism will be applied to the analysis of medical interviews in the area of diabetes care, and will be used to bring to light the sources of misunderstanding and the different presumptions that define distinct cultures. We will consequently illustrate the analytical tools by identifying and distinguishing the various types of ambiguity underlying misunderstandings, and we will address them by describing the communicative intentions ascribed to the ambiguous utterances.

Using tools like argument diagrams and profiles of dialogue, this paper studies a number of examples of everyday conversational argumentation where determination of relevance and irrelevance can be assisted by means of adopting a new dialectical approach. According to the new dialectical theory, dialogue types are normative frameworks with specific goals and rules that can be applied to conversational argumentation. In this paper is shown how such dialectical models of reasonable argumentation can be applied to a determination of whether an argument in a specific case is relevant are not in these examples. The approach is based on a linguistic account of dialogue and text from congruity theory, and on the notion of a dialectical shift. Such a shift occurs where an argument starts out as fitting into one type of dialogue, but then it only continues to makes sense as a coherent argument if it is taken to be a part of a different type of dialogue

The reasoning process of analogy is characterized by a strict interdependence between a process of abstraction of a common feature and the transfer of an attribute of the Analogue to the Primary Subject. The first reasoning step is regarded as an abstraction of a generic characteristic that is relevant for the attribution of the predicate. The abstracted feature can be considered from a logic-semantic perspective as a functional genus, in the sense that it is contextually essential for the attribution of the predicate, i.e. that is pragmatically fundamental (i.e. relevant) for the predica-tion, or rather the achievement of the communicative intention. While the transfer of the predicate from the Analogue to the analogical genus and from the genus to the Primary Subject is guaranteed by the maxims (or rules of inference) governing the genus-species relation, the connection between the genus and the predicate can be complex, characterized by various types of reasoning patterns. The relevance relation can hide implicit arguments, such as an implicit argument from classification , an evaluation based on values, consequences or rules, a causal relation, or an argument from practical reasoning.

There are emotively powerful words that can modify our judgment, arouse our emotions and influence our decisions. This paper shows how the use of emotive meaning in argumentation can be explained by showing how their logical dimension, which can be analysed using argumentation schemes, combines with heuristic processes triggered by emotions. Arguing with emotive words is shown to use value-based practical reasoning grounded on hierarchies of values and maxims of experience for evaluative classification.

The fields of linguistic pragmatics and legal interpretation are deeply interrelated. The purpose of this paper is to show how pragmatics and the developments in argumentation theory can contribute to the debate on legal interpretation. The relation between the pragmatic maxims and the presumptions underlying the legal canons are brought to light, unveiling the principles that underlie the types of argument usually used to justify a construction. The Gricean maxims and the arguments of legal interpretation are regarded as presumptions subject to default used to justify an interpretation. This approach can allow one to trace the different legal interpretive arguments back to their basic underlying presumptions, so that they can be compared, ordered, and assessed according to their defeasibility conditions. This approach allows one to understand the difference between various types of interpretive canons, and their strength in justifying an interpretation.

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.

Statutory interpretation involves the reconstruction of the meaning of a legal statement when it cannot be considered as accepted or granted. This phenomenon needs to be considered not only from the legal and linguistic perspective, but also from the argumentative one - which focuses on the strategies for defending a controversial or doubtful viewpoint. This book draws upon linguistics, legal theory, computing, and dialectics to present an argumentation-based approach to statutory interpretation. By translating and summarizing the existing legal interpretative canons into eleven patterns of natural arguments - called argumentation schemes - the authors offer a system of argumentation strategies for developing, defending, assessing, and attacking an interpretation. Illustrated through major cases from both common and civil law, this methodology is summarized in diagrams and maps for application to computer sciences. These visuals help make the structures, strategies, and vulnerabilities of legal reasoning accessible to both legal professionals and laypeople.

Metaphors can be used as crucial tools for reaching shared understanding, especially where an epistemic imbalance of knowledge is at stake. However, metaphors can also represent a risk in intercultural or cross-cultural interactions, namely in situations characterised by little or deficient common ground between interlocutors. In such cases, the use of metaphors can lead to misunderstandings and cause communicative breakdowns. The conditions defining when metaphors promote, and hinder understanding have not been analyzed in detail, especially in intracultural contexts. This study proposes an analysis of metaphors identified within an Italian corpus of diabetes care interviews. Through a coding scheme capturing the types and the probative weights of the linguistic evidence that can be used to detect misunderstandings, the communicative effectiveness of metaphors is indirectly assessed. The quantitative and qualitative analyses show a positive correlation between metaphor use and problematic understanding. A more detailed scrutiny of the interlocutors’ roles and topics of the metaphors points out that most of the problematic metaphors are used by patients, while most of the problematic ones used by providers concern non-clinical matters. These results can be explained as resulting from incorrect presumptions of common ground between the interlocutors.

In this paper we present an analysis of persuasive definition based on argumentation schemes. Using the medieval notion of differentia and the traditional approach to topics, we explain the persuasiveness of emotive terms in persuasive definitions by applying the argumentation schemes for argument from classification and argument from values. Persuasive definitions, we hold, are persuasive because their goal is to modify the emotive meaning denotation of a persuasive term in a way that contains an implicit argument from values. However, our theory is different from Stevenson’s, a positivistic view that sees emotive meaning as subjective, and defines it as a behavioral effect. Our proposal is to treat the persuasiveness produced by the use of emotive words and persuasive definitions as due to implicit arguments that an interlocutor may not be aware of. We use congruence theory to provide the linguistic framework for connecting a term with the function it is supposed to play in a text. Our account allows us to distinguish between conflicts of values and conflicts of classifications.

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.

Argument from analogy is a common and formidable form of reasoning in law and in everyday conversation. Although there is substantial literature on the subject, according to a recent survey ( Juthe 2005) there is little fundamental agreement on what form the argument should take, or on how it should be evaluated. Th e lack of conformity, no doubt, stems from the complexity and multiplicity of forms taken by arguments that fall under the umbrella of analogical reasoning in argumentation, dialectical studies, and law. Modeling arguments with argumentation schemes has proven useful in attempts to refine the analyst’s understanding of not only the logical structures that shape the backbone of the argument itself, but also the logical underpinning of strategies for evaluating it, strategies based on the semantic categories of genus and relevance. By clarifying the distinction between argument from example and argument from analogy, it is possible to advance a useful proposal for the treatment of argument from analogy in law.

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

We argue that common knowledge, of the kind used in reasoning in law and computing is best analyzed using a dialogue model of argumentation (Walton & Krabbe 1995). In this model, implicit premises resting on common knowledge are analyzed as endoxa or widely accepted opinions and generalizations (Tardini 2005). We argue that, in this sense, common knowledge is not really knowledge of the kind represent by belief and/or knowledge of the epistemic kind studied in current epistemology. This paper takes a different approach, defining it in relation to a common commitment store of two participants in a rule-governed dialogue in which two parties engage in rational argumentation (Jackson & Jacobs 1980; van Eemeren & Grootendorst 2004). A theme of the paper is how arguments containing common knowledge premises can be studied with the help of argumentation schemes for arguments from generally accepted opinion and expert opinion. It is argued that common knowledge is a species of provi- sional acceptance of a premise that is not in dispute at a given point in a dia- logue, but may later be defeated as the discussion proceeds

When we use a word, we face a crucial epistemic gap: we ground our move on the fact that our interlocutor knows the meaning of the word we used, and therefore he can interpret our dialogical intention. However, how is it possible to know the other’s mind? Hamblin explained this dialogical problem advancing the idea of dialectical meaning: on his view, the use of a word is based on a set of presumptions. Building on this approach, the use of a word in a dialogue can be analyzed in terms of presumptive reasoning, while the manipulative strategies based on slanted or loaded terms or redefinitions can be conceived as forms of conflicts of presumptions. A presumptive approach to meaning can also ground different dialectical strategies to solve misunderstanding or definitional disagreements, or tactics to undermine the interlocutor’s arguments by advancing charges of equivocation

Douglas Walton’s work is extremely vast, multifaceted, and interdisciplinary. He developed theoretical proposals that have been used in disciplines that are not traditionally related to philosophy, such as law, education, discourse analysis, artificial intelligence, or medical communication. Through his papers and books, Walton redefined the boundaries not only of argumentation theory, but also logic and philosophy. He was a philosopher in the sense that his interest was developing theoretical models that can help explain reality, and more importantly interact with it. For this reason, he proposed methods that have been used for analyzing different types of dialogical interactions, and modeling procedures for regulating them.

We contend that it is possible to argue reasonably for and against arguments from classifications and definitions, provided they are seen as defeasible (subject to exceptions and critical questioning). Arguments from classification of the most common sorts are shown to be based on defeasible reasoning of various kinds represented by patterns of logical reasoning called defeasible argumentation schemes. We show how such schemes can be identified with heuristics, or short-cut solutions to a problem. We examine a variety of arguments of this sort, including argument from abductive classification, argument from causal classification, argument from analogy-based classification and arguments from classification based on generalizations

The purpose of this paper is to inquire into the relationship between persuasive definition and common knowledge (propositions generally accepted and not subject to dispute in a discussion). We interpret the gap between common knowledge and persuasive definition (PD) in terms of potential disagreements: PDs are conceived as implicit arguments to win a potential conflict. Persuasive definitions are analyzed as arguments instantiating two argumentation schemes, argument from classification and argument from values, and presupposing a potential disagreement. The argumentative structure of PDs reveals different levels of disagreement, and different pos-sibilities of resolving the conflict or causing dialogical deadlock.

The classification of a state of affairs under a legal category can be considered as a kind of con- densed decision that can be made explicit, analyzed, and assessed us- ing argumentation schemes. In this paper, the controversial conflict of opinions concerning the nature of “marriage” in Obergefell v. Hodges is analyzed pointing out the dialecti- cal strategies used for addressing the interpretive doubts. The dispute about the same-sex couples’ right to marry hides a much deeper disa- greement not only about what mar- riage is, but more importantly about the dialectical rules for defining it.

The purpose of this paper is to analyze the structure and the defeasibility conditions of argument from analogy, addressing the issues of determining the nature of the comparison underlying the analogy and the types of inferences justifying the conclusion. In the dialectical tradition, different forms of similarity were distinguished and related to the possible inferences that can be drawn from them. The kinds of similarity can be divided into four categories, depending on whether they represent fundamental semantic features of the terms of the comparison or non-semantic ones, indicating possible characteristics of the referents. Such distinct types of similarity characterize different kinds of analogical arguments, all based on a similar general structure, in which a common genus is abstracted. Depending on the nature of the abstracted common feature, different rules of inference will apply, guaranteeing the attribution of the analogical predicate to the genus and to the primary subject. This analysis of similarity and the relationship thereof with the rules of inference allows a deeper investigation of the defeasibility conditions.

The analysis of multimodal argumentation in advertising is a crucial and problematic area of research. While its importance is growing in a time characterized by images and pictorial messages, the methods used for interpreting and reconstructing the structure of arguments expressed through verbal and visual means capture only isolated dimensions of this complex phenomenon. This paper intends to propose and illustrate a methodology for the reconstruction and analysis of “double-mode” arguments in advertisements, combining the instruments developed in social semiotics, pragmatics, and argumentation theory. An advertisement is processed through a five-step path. The analysis of its context, text genre, and images leads to a first representation of the messages that it encodes both pictorially and verbally (step 1). These first semantic representations are further enriched by including their polyphonic articulations and presuppositions (step 2), their explicatures (step 3), and their dialogical functions and illocutionary forces (step 4). These pragmatic steps retrieve the commitment structure of the ad, which allows a further argument analysis conducted through argumentation schemes (step 5).

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

The phenomenon of presupposition suspension can be analyzed in terms of explicatures and the corresponding non-presumptive interpretative reasoning underlying it. On the view presented in this paper, the polyphonic articulation of an utterance at different levels can be used to explain cases in which presuppositions are suspended. Presuppositional suspensions indicate that the presumptive reading does not hold and a different interpretation is needed. Utterances can display various types of polyphonic structures, accounting for the speaker’s and the hearer’s commitments. A speaker can be held directly responsible for what he says, but he is committed only indirectly to what he presupposes, i.e. what is uttered by a second voice (the second utterer or enunciator) representing what the common opinion accepts to be true. The reconstruction of the pragmatic structure of an utterance is guided by a complex type of reasoning, which can be represented as an argumentative abductive pattern, grounded on hierarchies of presumptions. By comparing the possible presumptions associated with the explicit meaning and the contextual information, the hearer can find a best possible explanation of the intended effect of the utterance.