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)

Olympiodorus led the Platonist school of philosophy at Alexandria for several decades in the sixth century, and both Platonic and Aristotelian commentaries ascribed to him survive. During this time the school’s attitude to the teaching of Aristotelian syllogistic, originally owing something to Ammonius, changed markedly, with an early tendency to reinforce the teaching of syllogistic even in Platonist lectures giving way to a greater awareness of its limitations. The vocabulary for arguments and their construction becomes far commoner than the (...) language of syllogistic and syllogistic figures, and also of demonstration. I discuss the value of these changes for the dating of certain works, especially where the text lectured on does not demand different emphases. The commitment to argument rather than to authority continues, but a greater emphasis eventually falls on the establishment of the premises than on formal validity. (shrink)

In the current paper, we re-examine how abstract argumentation can be formulated in terms of labellings, and how the resulting theory can be applied in the field of modal logic. In particular, we are able to express the (complete) extensions of an argumentation framework as models of a set of modal logic formulas that represents the argumentation framework. Using this approach, it becomes possible to define the grounded extension in terms of modal logic entailment.

In this paper, we prove the correspondence between complete extensions in abstract argumentation and 3-valued stable models in logic programming. This result is in line with earlier work of [6] that identified the correspondence between the grounded extension in abstract argumentation and the well-founded model in logic programming, as well as between the stable extensions in abstract argumentation and the stable models in logic programming.

The connection between logic programming and formal argumentation has been studied starting from the landmark 1995 paper of Dung. Subsequent work has identified a standard translation from logic programs to argumentation frameworks, under which pairwise correspondences hold between various logic programming semantics and various formal argumentation semantics. This includes the correspondence between 3-valued stable and complete semantics, between well-founded and grounded semantics and between 2-valued stable and stable semantics. In the current paper, we show that the existing translation (...) is able to yield the additional correspondence between ideal semantics for logic programming and ideal semantics for formal argumentation. We also show that correspondence does not hold between eager semantics for logic programming and eager semantics for formal argumentation, at least when translating from logic programming to formal argumentation. Overall, the current work should be seen as completing the analysis of correspondences between mainstream admissibility-based argumentation semantics and their logic programming counterparts. (shrink)

In legal decisions standpoints can be supported by formal and also by substantive interpretative arguments. Formal arguments consist of reasons the weight or force of which is essentially dependent on the authoritativeness that the reasons may also have: In this connection one may think of linguistic and systemic arguments. On the other hand, substantive arguments are not backed up by authority, but consist of a direct invocation of moral, political, economic, or other social considerations. (...) Formal arguments can be analyzed as exclusionary reasons: The authoritative character excludes—in principle—substantial counterarguments. Formal arguments are sometimes used to conceal value judgements based on substantial arguments. This paper deals with reconstructing problems regarding this strategic use of formal arguments in legal decisions, with a focus on linguistic argumentation. (shrink)

Positive rights are, roughly, rights that one be provided with certain things; and so they entail obligations on others, not merely to refrain from interfering with the bearer of the rights, but to see to it that one gets whatever one has the rights to. An example of a positive right would be the right to a welfare minimum; the right, that is, to resources sufficient to satisfy basic physical needs. In this paper I criticise a couple of recent attempts (...) (by Den Uyl and Machan, and by M. Levin) to show that alleged positive rights fail a purely formal test of universality and can thus be disqualified for that reason alone. (shrink)

The argument given by Peter van Inwagen for the second premise on his "First Formal Argument" in An Essay on Free Will is invalid. The second premise hinges on the principle that since a proposition p , some statement about the present, is actually true, ~p can't be true. ~p must be false. What is the reason? The principle is that ~p cannot be true at the same time as p . I argue that, among other things, in its (...) attachment to this sort of principle, van Inwagen's argument commits the most familiar of all the modal scope fallacies. (shrink)

This paper critically examines a formal argument against deducing ‘ought’-judgments from ‘is’-judgments, an argument suggested by a literal reading of a famous passage in Hume'sTreatise of Human Nature. According to this argument, judgments of the two kinds have different logical structures (i.e., their subjects are differently related to their predicates) and this difference disallows cross-categorical deductive inferences. I draw on Fregean accounts of the ‘is’- copula and on syntactical interpretations of ‘ought’-judgments that have become standard in deontic logic to (...) argue that twentieth century work in philosophical grammar and logic casts doubt on all three of the argument's premises. (shrink)

Traditional logical reconstruction of arguments aims at assessing the validity of ordinary language arguments. It involves several tasks: extracting argumentations from texts, breaking up complex argumentations into individual arguments, framing arguments in standard form, as well as formalizing arguments and showing their validity with the help of a logical formalism. These tasks are guided by a multitude of partly antagonistic goals, they interact in various feedback loops, and they are intertwined with the development of theories (...) of valid inference and adequate formalization. This paper explores how the method of reflective equilibrium can be used for modelling the complexity of such reconstructions and for justifying the various steps involved. The proposed approach is illustrated and tested in a detailed reconstruction of the beginning of Anselm’s De casu diaboli. (shrink)

The aim of this paper is to propose foundations for a formal model of representation and numerical evaluation of a possibly broad class of arguments, including those that occur in natural discourse. Since one of the most characteristic features of everyday argumentation is the occurrence of convergent reasoning, special attention should be paid to the operation ⊕, which allows us to calculate the logical force of convergent arguments with an accuracy not offered by other approaches.

This paper introduces the special issue on Formal Approaches to the Ontological Argument of the Journal of Applied Logics (College Publications). The issue contains the following articles: Formal Approaches to the Ontological Argument, by Ricardo Sousa Silvestre and Jean-Yves Béziau; A Brief Critical Introduction to the Ontological Argument and its Formalization: Anselm, Gaunilo, Descartes, Leibniz and Kant, by Ricardo Sousa Silvestre; A Mechanically Assisted Examination of Begging the Question in Anselm’s Ontological Argument, by John Rushby; A Tractarian Resolution (...) to the Ontological Argument, by Erik Thomsen; On Kant’s Hidden Ambivalence Toward Existential Generalization in his Critique of the Ontological Argument, by Giovanni Mion; The Totality of Predicates and the Possibility of the Most Real Being, by Srećko Kovač; An Even More Leibnizian Version of Gödel’s Ontological Argument, by Kordula Świętorzecka and Marcin Łyczak; A Case Study On Computational Hermeneutics: E. J. Lowe’s Modal Ontological Argument, by David Fuenmayor. (shrink)

In this paper, we introduce the systems ns-ACA₀ and ns-WKL₀ of non-standard second-order arithmetic in which we can formalize non-standard arguments in ACA₀ and WKL₀, respectively. Then, we give direct transformations from non-standard proofs in ns-ACA₀ or ns-WKL₀ into proofs in ACA₀ or WKL₀.

The purpose of this introduction is to give a rough overview of the discussion of the formalization of arguments, focusing on deductive arguments. The discussion is structured around four important junctions: i) the notion of support, which captures the relation between the conclusion and premises of an argument, ii) the choice of a formal language into which the argument is translated in order to make it amenable to evaluation via formal methods, iii) the question of quality (...) criteria for such formalizations, and finally iv) the choice of the underlying logic. This introductory discussion is supplemented by a brief description of the genesis of the special issue, acknowledgements, and summaries of each article. (shrink)

In this paper, we discuss formal reconstructions of Anselm’s ontological argument. We first present a number of requirements that any successful reconstruction should meet. We then offer a detailed preparatory study of the basic concepts involved in Anselm’s argument. Next, we present our own reconstructions—one in modal logic and one in classical logic—and compare them with each other and with existing reconstructions from the reviewed literature. Finally, we try to show why and how one can gain a better understanding (...) of Anselm’s argument by using modern formal logic. In particular, we try to explain why formal reconstructions of the argument, despite its apparent simplicity, tend to become quite involved. (shrink)

We show that certain model-theoretic forcing arguments involving subsystems of second-order arithmetic can be formalized in the base theory, thereby converting them to effective proof-theoretic arguments. We use this method to sharpen the conservation theorems of Harrington and Brown-Simpson, giving an effective proof that WKL+0 is conservative over RCA0 with no significant increase in the lengths of proofs.

Proof requires a dialogue between agents to clarify obscure inference steps, fill gaps, or reveal implicit assumptions in a purported proof. Hence, argumentation is an integral component of the discovery process for mathematical proofs. This work presents how argumentation theories can be applied to describe specific informal features in the development of proof-events. The concept of proof-event was coined by Goguen who described mathematical proof as a public social event that takes place in space and time. This new meta-methodological concept (...) is designed to cover not only “traditional” formal proofs but all kinds of proofs and inference steps, including incomplete or purported proofs. Our approach attempts to make proof-events more comprehensive to express the complete trajectory of a mathematical proof-event until the ultimate validation of the proving outcome. Thus, we advance an extended version of proof-event calculus which is built on argumentation theories designed to capture the internal and external structure of collaborative mathematical practice and highlight the relationship between proof, human reasoning, and cognitive processes. In addition, another area in which argumentation can make a significant contribution is dealing with the defeasible knowledge of the Web which is a product of its open and ubiquitous nature. This approach seems to be sufficient for the presentation of Web-based proving processes as manifested in the case of the Mini-Polymath 4 project. (shrink)

The wider topic to which the content of this paper belongs is that of the relationship between formal logic and real argumentation. Of particular potential interest in this connection are held to be substantive arguments constructed by philosophers reputed equally as authorities in logical theory. A number of characteristics are tentatively indicated by the author as likely to be encountered in such arguments. The discussion centers afterwards, by way of specification, on a remarkable piece of argument quoted (...) in Cicero’s dialog On Divination and ascribed to Stoic thinkers. The Stoics’ formal theory of inference is summarily referred to in this context, with special emphasis on their basic deductive schemata (‘indemonstrables’), some of them recognizable as links in the overall structure of the quoted argument. The main lines of Cicero’s criticism of the Stoic argument are next commented upon, with emphasis on his implied view as to the requirements of a good argument. Towards the end of the paper, a few considerations are added on the changes in the prevailing style of argumentation conspicuous in the three famous Roman Stoics. (shrink)

Lampert and Baumgartner (2010) critically discuss accounts of adequate formalization focusing on my analysis in (Brun 2004). There, I investigated three types of criteria of adequacy (matching truth conditions or inferential role, corresponding syntactical surface and systematicity) and argued that they ultimately call for a procedure of formalization. Although Lampert and Baumgartner have a point about matching truth conditions, their arguments target a truncated version of my account. They ignore all aspects of systematicity which make their counter-example unconvincing.

B F Scarlett; Formal and Teleological Elements in Hirst’s Argument for a Liberal Curriculum, Journal of Philosophy of Education, Volume 18, Issue 2, 30 May 2006.

B F Scarlett; Formal and Teleological Elements in Hirst’s Argument for a Liberal Curriculum, Journal of Philosophy of Education, Volume 18, Issue 2, 30 May 2006.

The central argument for functionalism is the so-called argument from multiple realizations. According to this argument, because a functionally characterized system admits a potential infinity of structurally diverse physical realizations, the functional organization of such systems cannot be captured in a law-like manner at the level of physical description (and, thus, must be treated as a principally autonomous domain of inquiry). I offer a rebuttal of this argument based on formal modeling of its premises in the framework of automata (...) theory. In this formal model I exploit the so-called minimal (universal) realizations of automata behaviors to show that the argument from multiple realizations is not just invalid but is refutable, in the sense that its premises (when made formally precise) entail the very opposite of the functionalist's conclusion. (shrink)

This paper presents a theory of reasoning with evidence in order to determine the facts in a criminal case. The focus is on the process of proof, in which the facts of the case are determined, rather than on related legal issues, such as the admissibility of evidence. In the literature, two approaches to reasoning with evidence can be distinguished, one argument-based and one story-based. In an argument-based approach to reasoning with evidence, the reasons for and against the occurrence of (...) an event, e.g., based on witness testimony, are central. In a story-based approach, evidence is evaluated and interpreted from the perspective of the factual stories as they may have occurred in a case, e.g., as they are defended by the prosecution. In this paper, we argue that both arguments and narratives are relevant and useful in the reasoning with and interpretation of evidence. Therefore, a hybrid approach is proposed and formally developed, doing justice to both the argument-based and the narrative-based perspective. By the formalization of the theory and the associated graphical representations, our proposal is the basis for the design of software developed as a tool to make sense of the evidence in complex cases. (shrink)

Three common strategies used by informal logicians are considered: (1) the appeal to standard cases, (2) the attempt to partially formalize so-called "informal fallacies," and (3) restatement of arguments in such a way as to make their logical character more perspicuous. All three strategies are found to be useful. Attention is drawn to several advantages of a "stock case" approach, a minimalist approach to formalization is recommended, and doubts are raised about the applicability, from a logical point of view, (...) of a principle of charitable construal in the reconstruction of arguments. (shrink)

This paper sharpens the distinction between inferential and logcon arguments. Inferential arguments represent possible inferences, logcon ones need not. This distinction clarifies the roles that arguments play in accounting for the normativity of validity for inferential reasoning and in establishing the theoretical connection between validity and logical consequence. There are two related takeaways. First, the normativity of validity for inferential reasoning is grounded on the notion of an inferential argument. This will account for the use of validity (...) to judge inference in the face of well-known skepticism that a theory of validity has any special relevance to inferential reasoning. Second, a valid logcon argument needn't be an inferential argument. Accordingly, the normativity of validity for inferential reasoning doesn't require that every valid logcon argument be an inferential argument. The takeaways harmonize the use of validity to evaluate inferential reasoning with the use of the concept of logical consequence to characterize validity. (shrink)

This paper studies the modelling of legal reasoning about evidence within general theories of defeasible reasoning and argumentation. In particular, Wigmore's method for charting evidence and its use by modern legal evidence scholars is studied in order to give a formal underpinning in terms of logics for defeasible argumentation. Two notions turn out to be crucial, viz. argumentation schemes and empirical generalisations.

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

he general theme of this paper is the issue of formalization in philosophy; in a more specific way, it deals with the issue of formalization of arguments in analytic philosophy of religion. One argument in particular – Anselm’s Proslogion II ontological argument – and one specific attempt to formalize it – Robert Adams’ formalization found in his paper “The Logical Structure of Anselm’s Arguments”, published in The Philosophical Review in 1971 – are taken as study cases. The purpose (...) of the paper is to critically analyze Adams’ formalization with the intent to shed some light on the following questions: What are the virtues of formally analyzing arguments and the contributions, if any, of such an enterprise to the debate on Anselm’s argument? Which lessons can Adam’s work teach us about the dangers and limitations of formalization? Do these virtues and dangers teach us something about analysis of arguments in general? (shrink)