Argumentation Frameworks provide a fruitful basis for exploring issues of defeasible reasoning. Their power largely derives from the abstract nature of the arguments within the framework, where arguments are atomic nodes in an undifferentiated relation of attack. This abstraction conceals different senses of argument, namely a single-step reason to a claim, a series of reasoning steps to a single claim, and reasoning steps for and against a claim. Concrete instantiations encounter difficulties and complexities as a result of conflating these (...) senses. To distinguish them, we provide an approach to instantiating AFs in which the nodes are restricted to literals and rules, encoding the underlying theory directly. Arguments in these senses emerge from this framework as distinctive structures of nodes and paths. As a consequence of the approach, we reduce the effort of computing argumentation extensions, which is in contrast to other approaches. Our framework retains the theoretical and computational bene.. (shrink)

In many domains of public discourse such as arguments about public policy, there is an abundance of knowledge to store, query, and reason with. To use this knowledge, we must address two key general problems: first, the problem of the knowledge acquisition bottleneck between forms in which the knowledge is usually expressed, e.g., natural language, and forms which can be automatically processed; second, reasoning with the uncertainties and inconsistencies of the knowledge. Given such complexities, it is labour and knowledge intensive (...) to conduct policy consultations, where participants contribute statements to the policy discourse. Yet, from such a consultation, we want to derive policy positions, where each position is a set of consistent statements, but where positions may be mutually inconsistent. To address these problems and support policy-making consultations, we consider recent automated techniques in natural language processing, instantiating arguments, and reasoning with the arguments in argumentation frameworks. We discuss application and “bridge” issues between these techniques, outlining a pipeline of technologies whereby: expressions in a controlled natural language are parsed and translated into a logic (a literals and rules knowledge base), from which we generate instantiated arguments and their relationships using a logic-based formalism (an argument knowledge base), which is then input to an implemented argumentation framework that calculates extensions of arguments (an argument extensions knowledge base), and finally, we extract consistent sets of expressions (policy positions). The paper reports progress towards reasoning with web-based, distributed, collaborative, incomplete, and inconsistent knowledge bases expressed in natural language. (shrink)

In many domains of public discourse such as arguments about public policy, there is an abundance of knowledge to store, query, and reason with. To use this knowledge, we must address two key general problems: first, the problem of the knowledge acquisition bottleneck between forms in which the knowledge is usually expressed, e.g., natural language, and forms which can be automatically processed; second, reasoning with the uncertainties and inconsistencies of the knowledge. Given such complexities, it is labour and knowledge intensive (...) to conduct policy consultations, where participants contribute statements to the policy discourse. Yet, from such a consultation, we want to derive policy positions, where each position is a set of consistent statements, but where positions may be mutually inconsistent. To address these problems and support policy-making consultations, we consider recent automated techniques in natural language processing, instantiating arguments, and reasoning with the arguments in argumentation frameworks. We discuss application and “bridge” issues between these techniques, outlining a pipeline of technologies whereby: expressions in a controlled natural language are parsed and translated into a logic (a literals and rules knowledge base), from which we generate instantiated arguments and their relationships using a logic-based formalism (an argument knowledge base), which is then input to an implemented argumentation framework that calculates extensions of arguments (an argument extensions knowledge base), and finally, we extract consistent sets of expressions (policy positions). The paper reports progress towards reasoning with web-based, distributed, collaborative, incomplete, and inconsistent knowledge bases expressed in natural language. (shrink)

We study instantiated abstract argumentation frames of the form, where is an abstract argumentation frame and where the arguments x of S are instantiated by I as well formed formulas of a well known logic, for example as Boolean formulas or as predicate logic formulas or as modal logic formulas. We use the method of conceptual analysis to derive the properties of our proposed system. We seek to define the notion of complete extensions for such systems (...) and provide algorithms for finding such extensions. We further develop a theory of instantiation in the abstract, using the framework of Boolean attack formations and of conjunctive and disjunctive attacks. We discuss applications and compare critically with the existing related literature. (shrink)

According to traditional universalism, properties are instantiated by objects, where instantiation is a ‘tie’ that binds objects and properties into facts. I offer two arguments against this view. I then develop an alternative higher-order account which holds that properties are primitively predicated of objects yet, unlike traditional nominalism, are nevertheless genuinely real. When it’s a fact that Fo, it’s not because object o instantiates F-ness, but just that Fo – where F still exists. Against orthodox higher-order approaches, however, my (...) arguments against instantiation also serve to support a sparse conception of properties. In developing the view, I introduce an extension of ontological and ideological commitment in the form of syntactic commitment. (shrink)

I examine two arguments for nonconceptualism from the phenomenal character of perceptual experience. The idea is that only the assumption that experience content is nonconceptual does justice to the phenomenology of experience. In particular, if experience content is conceptual, we cannot account for its finely grained representational content. The problem is that visual color experience makes differences between shades of a color that are much more fine-grained than our conceptual repertoire allows. Further, conceptualism is incompatible with the situation-dependence of perceptual (...) content Kelly (Philos Phenomenol Res 62:601–608, 2001b). For instance, it is hard if not impossible to make room, in purely conceptual terms, for the difference between perceiving a certain shade of purple instantiated by a steel ball as compared to seeing it instantiated by a wool carpet. As to the argument from fineness of grain, I concede that the conceptualist’s demonstrative strategy against the argument is initially successful. However, it fails in the end because of problems with the phenomenal character of hallucination, which cannot be accounted for by appeal to only demonstrative concepts. As to the argument from situation-dependence, I point out that the conceptualist cannot convincingly account for the perceived presence, at the same time and in the same place, of situation-dependent and independent properties in experience. (shrink)

In a recent paper, Breckenridge and Magidor argue for an interesting and counterintuitive account of instantial reasoning. According to this account, in arguments such as one beginning with 'There is some x such that x is mortal. Let O be such an x. ...', the 'O' refers to a particular object, although we cannot know which. I give and defend a simple counterexample involving the notion of an unreferred-to object.

The paper is an attempt to explain what a transcendental argument is for Kant. The interpretation is based on a reading of the 'Discipline of Pure Reason', Sections 1 and 4 of the first Critique. The author first identifies several statements that Kant makes about the method of proof he followed in the 'Analytic of Principles' which seem to be inconsistent. He then tries to remove the apparent inconsistencies by focusing on the idea of instantiation and drawing a distinction between (...) the intension and the extension of a concept. Finally, the results are applied to the second 'Analogy of Experience' for the purposes of illustration. The paper should be seen as an attempt to provide an historical answer to a question that has been treated thematically in much of the recent literature. (shrink)

In multi-agent systems (MAS), abstract argumentation and argumentation schemes are increasingly important. To be useful for MAS, argumentation schemes require a computational approach so that agents can use the components of a scheme to construct and present arguments and counterarguments. This paper proposes a syntactic analysis that integrates argumentation schemes with abstract argumentation. Schemes can be analysed into the roles that propositions play in each scheme and the structure of the associated propositions, yielding a greater (...) understanding of the schemes, a uniform method of analysis, and a systematic means to relate one scheme to another. This analysis of the schemes helps to clarify what is needed to provide denotations of the terms and predicates in a semantic model. (shrink)

In this contribution the prototypical argumentative patterns are discussed in which pragmatic argumentation is used in the context of legal justification in hard cases. First, the function and implementation of pragmatic argumentation in prototypical argumentative patterns in legal justification are addressed. The dialectical function of the different parts of the complex argumentation are explained by characterizing them as argumentative moves that are put forward in reaction to certain forms of critique. Then, on the basis of an exemplary (...) case, the famous Holy Trinity case, the way in which the U.S. Supreme Court uses pragmatic argumentation in this case is discussed by showing how the court instantiates general prototypical argumentative patterns in light of the institutional preconditions of the justification in the context of the specific case. (shrink)

We present a high-level declarative programming language for representing argumentation schemes, where schemes represented in this language can be easily validated by domain experts, including developers of argumentation schemes in informal logic and philosophy, and serve as executable specifications for automatically constructing arguments, when applied to a set of assumptions. Since argumentation schemes are defeasible inference rules, both premises and conclusions of schemes can be second-order schema variables, i.e. without a fixed predicate symbol. Thus, while particular schemes (...) can be and have been implemented in computer programs, in general argumentation schemes cannot be represented as executable specifications using logic programming languages based on first-order logic, such as Prolog. Moreover, even if the conclusion (head) of Prolog rules could be second-order variables, a depth-first, backward-chaining search strategy, as typically used in logic programming, would usually cause such programs to not terminate, since every goal would match the head of such a scheme, including all goals created by instantiating the body of the same scheme. The language for representing argumentation schemes presented here, for the purpose of automatically constructing arguments, uses Constraint Handling Rules (CHR), a declarative, Turing complete, forwards-chaining, rule-based programming language introduced by Thom Frühwirth in 1991. CHR is attractive for representing and implementing argumentation for several reasons, including: 1) Inference rules, rewrite rules, sequents, proof rules, and logical axioms can be directly written in CHR. 2) The execution of CHR rules can be interrupted and restarted at any time, with intermediate results approximating the final solution, and 3) Constraints can be input incrementally as they become known, during rule execution, without requiring recomputation. These three properties of CHR appear attractive for representing and implementing argumentation schemes. Since argumentation schemes are (defeasible) inference rules, the ability of CHR to represent inference rules directly would appear to be quite useful. The ability to stop the computation and produce approximate results is compatible with one objective of argumentation, to provide a principled method for supporting approximate reasoning with limited resources. Because argumentation typically takes place in dialogs, with evidence and arguments brought forward and asserted by the participants incrementally, during the course of the dialog, CHR’s ability to handle new information, incrementally introduced during the computation, may be useful. This new rule language for representing argumentation schemes is validated by using it to represent twenty representative argumentation schemes. (shrink)

There is disagreement over the notion of representation in cognitive science. Many investigators equate representations with symbols, that is, with syntactically defined elements in an internal symbol system. In recent years there have been two challenges to this orthodoxy. First, a number of philosophers, including many outside the symbolist orthodoxy, have argued that "representation" should be understood in its classical sense, as denoting a "stands for" relation between representation and represented. Second, there has been a growing challenge to orthodoxy under (...) the banner of connectionism. Although this connectionist challenge has evoked emotionally-charged rebukes from the symbolist camp, connectionists as a group have not articulated a conception of representation to replace the symbolist view. Nonetheless, most agree on the need for a nonsymbolic notion of representation. This paper advances a "stands for" sense of representation as primary by incorporating it into a general approach to cognitive science consonant with the connectionism. The idea is to marry connectionism to a particular version of functionalism, viz., one that builds its notion of "function" on the similarity between functional analysis in biology and in psychology. It builds on my earlier work adapting and revising Marr's tri-level approach to cognition. My proposal frees Marr's analysis from its moorings in the orthodox symbolic view of representation and allies it with a notion of functional analysis akin to that proposed by Cummins, developed further by Haugeland, and invoked by Millikan and Dretske. Unlike these authors, however, I do not wed representation to a general belief-desire analysis of behavior. Rather, I follow what I take to be the lesson of psychological practice, according to which the investigator does not seek to explain behavior in general but seeks to analyze the cognitive capacities that underlie behavior, such as vision, memory, learning, and linguistic capacities. Accordingly, ascriptions of representational content are made not by working back from belief-desire ascriptions, but in the context of forming psychological models to account for specific cognitive capacities. Because conceptions of representation in cognitive science typically are embedded in a general approach to the study of cognition, arguments for the comparative plausibility of a particular conception of representation must scout these larger frameworks. I therefore begin by characterizing the interlocking set of assumptions that gave life to the orthodox symbolist approach, paying special attention to the complementarity between representation and process that naturally arises from those assumptions. I then consider two versions of an alternative approach to representation: Dretske's and my own. Finally, I urge the merits of the "cognitive capacities" over the "belief-desire" approach to the subject-matter of cognitive science. (shrink)

I distinguish between instantial sentences (_There are elephants that swim_), particular quantification, and predication of existence in natural language. I explore the logical relation between the first two, while the last one is shown independent of either. I continue to consider the incorporation of the three kinds of sentence in the Quantified Argument Calculus (Quarc). I provide formalisations that preserve the logical relations specified earlier. I also extend the analysis to quantified instantial sentences (_There are_ five _elephants that swim_) and (...) modal ones. A conclusion of this work is that quantification and instantial sentences provide no guide to ontology. (shrink)

Dombrowski and Murdoch offer versions of the ontological argument which aim to avoid two types of objection – those concerned with the nature of the divine, and those concerned with the move from an abstract concept to a mind-independent reality. For both, the nature of the concept of God/Good entails its instantiation, and both supply a supporting argument from experience. It is only Murdoch who successfully negotiates the transition from an abstract concept to the instantiation of that concept, however, and (...) this is achieved by means of an ontological argument from moral experience which, in a reversal of the Kantian doctrine, depends ultimately on a form of the cosmological argument. (shrink)

In multi-agent systems (MAS), abstract argumentation and argumentation schemes are increasingly important. To be useful for MAS, argumentation schemes require a computational approach so that agents can use the components of a scheme to construct and present arguments and counterarguments. This paper proposes a syntactic analysis that integrates argumentation schemes with abstract argumentation. Schemes can be analysed into the roles that propositions play in each scheme and the structure of the associated propositions, yielding a greater (...) understanding of the schemes, a uniform method of analysis, and a systematic means to relate one scheme to another. This analysis of the schemes helps to clarify what is needed to provide denotations of the terms and predicates in a semantic model. (shrink)

The argument from appearance for the content view or intentionalism attracts a lot of attention recently. In my paper, I follow Charles Travis to argue against the key premise that representational content can be ‘read off’ from a certain way that a thing looks to a subject. My arguments are built upon Travis’s original objection and a reinterpretation of Rodrick Chisholm’s comparative and noncomparative uses of appearance words. Byrne, Schellenberg and others interpret Travis’ ‘visual looks’ as Chisholm’s comparative use, and (...) appeal to the noncomparative use as an alternative to avoid Travis’s objection. I demonstrate that they misunderstand both Chisholm and Travis. Both the comparative use and the noncomparative use are semantic notions, while ‘visual looks’ is a metaphysical one. Although Chisholm’s appearance objectivism –– that appearance expressions attribute appearances to ordinary objects –– is close to ‘visual looks’, appearance objectivism is not exceptional to the noncomparative use as Byrne interprets. In the end, I also show that Byrnean’s conception of distinctive visual gestalt cannot exclude contrary representational contents, because a distinctive visual gestalt can be shared by different kinds of things. Besides, Byrne and others do not explain why a distinctive visual gestalt should be presented as ‘being instantiated’. Therefore, I conclude that representational content cannot be read off from a certain way that a thing looks to a subject; the argument from appearance thus fails. (shrink)

An abstract framework for structured arguments is presented, which instantiates Dung's ('On the Acceptability of Arguments and its Fundamental Role in Nonmonotonic Reasoning, Logic Programming, and n- Person Games', Artificial Intelligence , 77, 321-357) abstract argumentation frameworks. Arguments are defined as inference trees formed by applying two kinds of inference rules: strict and defeasible rules. This naturally leads to three ways of attacking an argument: attacking a premise, attacking a conclusion and attacking an inference. To resolve such attacks, preferences (...) may be used, which leads to three corresponding kinds of defeat: undermining, rebutting and undercutting defeats. The nature of the inference rules, the structure of the logical language on which they operate and the origin of the preferences are, apart from some basic assumptions, left unspecified. The resulting framework integrates work of Pollock, Vreeswijk and others on the structure of arguments and the nature of defeat and extends it in several respects. Various rationality postulates are proved to be satisfied by the framework, and several existing approaches are proved to be a special case of the framework, including assumption-based argumentation and DefLog. (shrink)

In this paper, we introduce the methodology and techniques of metaargumentation to model argumentation. The methodology of meta-argumentation instantiates Dung's abstract argumentation theory with an extended argumentation theory, and is thus based on a combination of the methodology of instantiating abstract arguments, and the methodology of extending Dung's basic argumentation frameworks with other relations among abstract arguments. The technique of meta-argumentation applies Dung's theory of abstract argumentation to itself, by instantiating Dung's abstract arguments (...) with meta-arguments using a technique called flattening. We characterize the domain of instantiation using a representation technique based on soundness and completeness. Finally, we distinguish among various instantiations using the technique of specification languages. (shrink)

We propose a revised definition of “argument scheme” that focuses on describing argumentative performances and normative assessments that occur within an argumentative context, the social context in which the scheme arises. Our premise-and-conclusion structure identifies the typical instantiation of an argument in the argumentative context, and our critical framework describes a set of normative assessments available to participants in the context, what we call _practically normative_ assessments. We distinguish this practical normativity from the _rationally or universally normative_ assessment that might (...) be imposed from outside the argumentative context. Thus, the practical norms represented in an argument scheme may still be subject to rational critique, and the scheme avoids the is/ought fallacy. We ground our theoretical discussion and observations in an empirical study of US district court opinions resolving legal questions about copyright fair use and the lawyers’ briefs that led to them, instantiating our definition of argument scheme in the “argument for classification by precedent.” Our definition addresses some criticisms the argument-scheme construct has received. For example, using our data, we show that a minimally well formed instance of this type of argument does not shift any conventional burden from the proponent of the argument to its skeptics. We also argue that these argument schemes need not be seen as dialogical. (shrink)

In this article, the theory of argumentation set out by the Dutch scholars Frans van Eemeren and Rob Grootendorst is brought to bear in subjecting the general form of the argument from coherence to a critical analysis. First, a distinction is brought out between two basic kinds of argument from coherence: in one use this argumentative structure occurs as a sequence of two arguments establishing that a standpoint constitutes a particular instantiation or a inherent quality of the system it (...) will become part of (symptomatic argument); in the other use we have a main symptomatic argument supported by a subordinate argument appealing to instrumental considerations (pragmatic argument). It is then claimed that arguments from coherence are complex types of argumentation, structured at various argumentative levels, where the premises must be taken together to yield an adequate defence of the conclusion (coordinative argumentation). Finally, an evaluative assessment is made as to whether arguments from coherence can serve acceptably as tools for settling disputes: it will be maintained that we can generally welcome these argumentative structures as sound and fully acceptable provided we are aware of the interpretive discretion their use entails. (shrink)

This paper examines from a cognitive perspective the rhetorical and epistemic advantages that can be gained from the use of (extended) metaphors in political discourse. We defend the assumption that extended metaphors can be argumentatively exploited, and provide two arguments in support of the claim. First, considering that each instantiation of the metaphorical mapping in the text may function as a confirmation of the overall relevance of the main core mapping, we argue that extended metaphors carry self-validating claims that increase (...) the chances of their content being accepted. Second, we show how the recognition of an extended metaphor’s sophistication and relevance (on behalf of the addressee) can benefit the speaker’s perceived competence (ethos). We then assess whether these two arguments measure against the dual epistemic monitoring postulated in the notion of epistemic vigilance (i.e., assessment of the source of a message and assessment of the message) and conclude that extended metaphors may fulfil the requirements of epistemic vigilance and lead to the stabilisation of a belief. We illustrate our account with an analysis of the extended metaphor of the USA as an empire found in a political pamphlet written by the Swiss politician Oskar Freysinger. (shrink)

This paper aims at a normative account of non-deductive argumentation schemes in the spirit of Hamblin’s dialectical philosophy. First, three principles are presented that characterize Hamblin’s dialectical stance. Second, argumentation schemes, which have hardly been examined in Hamblin’s book Fallacies, shall be dealt with by applying these principles, taking an argumentation scheme from authority as the leading example. Third, a formal dialectical system, along the lines indicated by Hamblin, shall be developed that includes norms for using (...) class='Hi'>argumentation schemes and norms for responding to arguments that are presented as instantiating acceptable argumentation schemes. (shrink)

That bootstrapping and Moorean reasoning fail to instantiate persuasive argumentation is an often informally presented but not systematically developed view. In this paper, I will argue that this unpersuasiveness is not determined by principles of justification transmission but by two straightforward principles of rationality, understood as a concept of internal coherence. First, it is rational for S to believe the conclusion of an argument because of the argument, only if S believes sufficiently many premises of the argument. Second, if (...) S doubts that a source _O_ is reliable and believes that information _i_ is delivered by _O_, then S rationally suspends judgment about the truth of _i_. This paper aims to accomplish two tasks. First, it provides a thorough analysis of why bootstrapping argumentation is not an instance of rational persuasion. Second, it contains a more general theory about preconditions and limits of persuasive argumentation. (shrink)

In this paper, we introduce the methodology and techniques of meta-argumentation to model argumentation. The methodology of meta-argumentation instantiates Dung’s abstract argumentation theory with an extended argumentation theory, and is thus based on a combination of the methodology of instantiating abstract arguments, and the methodology of extending Dung’s basic argumentation frameworks with other relations among abstract arguments. The technique of meta-argumentation applies Dung’s theory of abstract argumentation to itself, by instantiating Dung’s abstract (...) arguments with meta-arguments using a technique called flattening. We characterize the domain of instantiation using a representation technique based on soundness and completeness. Finally, we distinguish among various instantiations using the technique of specification languages. (shrink)

The centrality of argumentation in the judicial process is an age-old acquisition of research on legal discourse. Notwithstanding the deep insights provided by legal theoretical and philosophical works, only recently has judicial argumentation been tackled in its linguistic dimension. This paper aims to contribute to the development of linguistic studies of judicial argumentation, by shedding light on evaluation as a prominent aspect in the construction of the judge’s argumentative position. Evaluation as a deep structure of judicial (...) class='Hi'>argumentation is studied from a discursive point of view entailing the analysis of a sample of authentic judicial language. Evaluative lexis is investigated within a single genre of judicial discourse, i.e. judgments, instantiated by a corpus of US Supreme Court judgments. Findings show that judges use diversified strategies to take stance as they organise their argumentative discourse: from easily recognisable verbal and adjectival tools to more finely-grained discourse elements such as the encapsulating pattern ‘this/these/that/those + labelling noun’. (shrink)

Dung’s (1995) argumentation framework takes as input two abstract entities: a set of arguments and a binary relation encoding attacks between these arguments. It returns acceptable sets of arguments, called extensions, w.r.t. a given semantics. While the abstract nature of this setting is seen as a great advantage, it induces a big gap with the application that it is used to. This raises some questions about the compatibility of the setting with a logical formalism (i.e., whether it is possible (...) to instantiate it properly from a logical knowledge base), and about the significance of the various semantics in the application context. In this paper we tackle the above questions. We first propose to fill in the previous gap by extending Dung’s (1995) framework. The idea is to consider all the ingredients involved in an argumentation process. We start with the notion of an abstract monotonic logic which consists of a language (defining the formulas) and a consequence operator. We show how to build, in a systematic way, arguments from a knowledge base formalised in such a logic. We then recall some basic postulates that any instantiation should satisfy. We study how to choose an attack relation so that the instantiation satisfies the postulates. We show that symmetric attack relations are generally not suitable. However, we identify at least one ‘appropriate’ attack relation. Next, we investigate under stable, semi-stable, preferred, grounded and ideal semantics the outputs of logic-based instantiations that satisfy the postulates. For each semantics, we delimit the number of extensions an argumentation system may have, characterise the extensions in terms of subsets of the knowledge base, and finally characterise the set of conclusions that are drawn from the knowledge base. The study reveals that stable, semi-stable and preferred semantics either lead to counter-intuitive results or provide no added value w.r.t. naive semantics. Besides, naive semantics either leads to arbitrary results or generalises the coherence-based approach initially developed by Rescher and Manor (1970). Ideal and grounded semantics either coincide and generalise the free consequence relation developed by Benferhat, Dubois, and Prade (1997), or return arbitrary results. Consequently, Dung’s (1995) framework seems problematic when applied over deductive logical formalisms. (shrink)

The paper provides an OWL ontology for legal cases with an instantiation of the legal case Popov v. Hayashi. The ontology makes explicit the conceptual knowledge of the legal case domain, supports reasoning about the domain, and can be used to annotate the text of cases, which in turn can be used to populate the ontology. A populated ontology is a case base which can be used for information retrieval, information extraction, and case based reasoning. The ontology contains not only (...) elements for indexing the case (e.g. the parties, jurisdiction, and date), but as well elements used to reason to a decision such as argument schemes and the components input to the schemes. We use the Protégé ontology editor and knowledge acquisition system, current guidelines for ontology development, and tools for visual and linguistic presentation of the ontology. (shrink)

In this article the argumentation structure of the court’s decision in the Popov v. Hayashi case is formalised in Prakken’s (Argument Comput 1:93–124; 2010) abstract framework for argument-based inference with structured arguments. In this framework, arguments are inference trees formed by applying two kinds of inference rules, strict and defeasible rules. Arguments can be attacked in three ways: attacking a premise, attacking a conclusion and attacking an inference. To resolve such conflicts, preferences may be used, which leads to three (...) corresponding kinds of defeat, after which Dung’s (Artif Intell 77:321–357; 1995) abstract acceptability semantics can be used to evaluate the arguments. In the present paper the abstract framework is instantiated with strict inference rules corresponding to first-order logic and with defeasible inference rules for defeasible modus ponens and various argument schemes. The main techniques used in the formal reconstruction of the case are rule-exception structures and arguments about rule validity. Arguments about socio-legal values and the use of precedent cases are reduced to arguments about rule validity. The tree structure of arguments, with explicit subargument relations between arguments, is used to capture the dependency relations between the elements of the court’s decision. (shrink)

In this paper we describe an approach to practical reasoning, reasoning about what it is best for a particular agent to do in a given situation, based on presumptive justifications of action through the instantiation of an argument scheme, which is then subject to examination through a series of critical questions. We identify three particular aspects of practical reasoning which distinguish it from theoretical reasoning. We next provide an argument scheme and an associated set of critical questions which is able (...) to capture these features. In order that both the argument scheme and the critical questions can be given precise interpretations we use the semantic structure of an Action-Based Alternating Transition System as the basis for their definition. We then work through a detailed example to show how this approach to practical reasoning can be applied to a problem solving situation, and briefly describe some other previous applications of the general approach. In a second example we relate our account to the social laws paradigm for co-ordinating multi-agent systems. The contribution of the paper is to provide firm foundations for an approach to practical reasoning based on presumptive argument in terms of a well-known model for representing the effects of actions of a group of agents. (shrink)

Probabilism in epistemology does not have to be of the Bayesian variety. The probabilist represents a person''s opinion as a probability function; the Bayesian adds that rational change of opinion must take the form of conditionalizing on new evidence. I will argue that this is the correct procedure under certain special conditions. Those special conditions are important, and instantiated for example in scientific experimentation, but hardly universal. My argument will be related to the much maligned Reflection Principle (van Fraassen, (...) 1984, 1995), and partly inspired by the work of Brian Skyrms (1987). (shrink)

The article argues that lesbian, gay, bisexual, and transgendered (LGBT) rights are a particular instantiation of human rights. But in order to make this argument several things must be done first. Preliminarily, it should be noted that some transgendered issues fall under the rubric "gay rights," even though strictly speaking, they center most prominently on gender and not sexual orientation. Still, there gender aspects are often ignored because of concerns related to sexual orientation, such as whether a transgendered female can (...) use a woman's washroom. Arguably, the reverse may also be true of gays, lesbians, and bisexuals, as many of society's concerns regarding this group involve their following gender roles, even though the discrimination against them is not usually seen as sex discrimination. Bearing that in mind, among the various responsibilities of this article is to define--in the broad sense--what gay and lesbian rights are. This is followed by a similar set of expressions defining what human rights are and an argument for how such rights get justified. Once that is done, the connection between gay and lesbian rights and human rights is pursued within the context of a theory of political morality that establishes the centrality of human rights to all moral concerns. (shrink)

This paper proposes an approach to investigate norm-governed learning agents which combines a logic-based formalism with an equation-based counterpart. This dual formalism enables us to describe the reasoning of such agents and their interactions using argumentation, and, at the same time, to capture systemic features using equations. The approach is applied to norm emergence and internalisation in systems of learning agents. The logical formalism is rooted into a probabilistic defeasible logic instantiating Dung’s argumentation framework. Rules of this logic (...) are attached with probabilities to describe the agents’ minds and behaviours as well as uncertain environments. Then, the equation-based model for reinforcement learning, defined over this probability distribution, allows agents to adapt to their environment and self-organise. (shrink)

In this paper, we introduce the methodology and techniques of meta-argumentation to model argumentation. The methodology of meta-argumentation instantiates Dung’s abstract argumentation theory with an extended argumentation theory, and is thus based on a combination of the methodology of instantiating abstract arguments, and the methodology of extending Dung’s basic argumentation frameworks with other relations among abstract arguments. The technique of meta-argumentation applies Dung’s theory of abstract argumentation to itself, by instantiating Dung’s abstract (...) arguments with meta-arguments using a technique called flattening. We characterize the domain of instantiation using a representation technique based on soundness and completeness. Finally, we distinguish among various instantiations using the technique of specification languages. (shrink)

Is it possible that there are extended simples—material objects extended in space or spacetime that have no proper parts? The most commonly cited argument for this possibility is based on a version of the Humean principle: namely (and with some qualifications), any pattern of instantiation of a fundamental relation is possible. In this paper, we make the Humean argument fully explicit, and criticise it from three aspects—the Disjunction problem, the Pluralist problem, and the Accidentality problem. First, the original argument only (...) shows a disjunctive thesis: either extended simples are possible, or unextended complexes are possible. In order to reach the desired conclusion, some additional premise is needed. Yet, even though we agree that the Disjunction problem can be met, we argue that the Humean argument fails to establish the possibility of extended simples, for two reasons: the first comes from compositional pluralism, and the second is about the definition of accidental properties. We contend that the latter two problems put the proponents of the Humean argument in serious difficulty. Thus, metaphysicians who hold that there are extended simples should find better arguments for this view. (shrink)

By “epistemic pragmatism” in general I will understand the claim that whether propositions instantiate certain key epistemic properties (such as being known or being justifiably believed) depends not just on factors traditionally recognized as epistemic, but also on pragmatic factors, such as how costly it would be to the subject if the proposition were false. In what follows I consider two varieties of epistemic pragmatism. According to what I shall call moderate epistemic pragmatism, how much evidence we need in favor (...) of a proposition in order to know that the proposition is true depends on our preferences. According to what I shall call extreme epistemic pragmatism, on the other hand, our preferences influence our epistemic position at a more basic level, because they help determine how much justification we actually have in favor of the proposition in question. Simplifying brutally, moderate epistemic pragmatism has it that the more worried we are about a proposition’s being false, the more justification we need in order to know it, whereas extreme epistemic pragmatism has it that the more worried we are about a proposition’s being false, the less justification we have for it. Recently, Fantl and McGrath have presented an interesting argument for moderate epistemic pragmatism, an argument which relies on the principle that (roughly) knowledge is sufficient for action (KA). In this paper I argue that KA, together with a plausible principle about second-order evidence, entails extreme epistemic pragmatism. (shrink)

Arguments are movements of thought. From a logical point of view, such a movement is justifiable as it tends to preserve or transmit truth. To speak of such tendency is to abstract from particular movements of thought and to ascent to the forms of such movements. Thus logical theory is said to concern rules of validity or cogency that one may use to evaluate forms of arguments, forms as may be instantiated by particular sets of statements which we may (...) use to represent particular movements of thought. (shrink)

In the 1980s, Pollock’s work on default reasons started the quest in the AI community for a formal system of defeasible argumentation. The main goal of this paper is to provide a logic of structured defeasible arguments using the language of justification logic. In this logic, we introduce defeasible justification assertions of the type t : F that read as “t is a defeasible reason that justifies F”. Such formulas are then interpreted as arguments and their acceptance semantics is (...) given in analogy to Dung’s abstract argumentation framework semantics. We show that a large subclass of Dung’s frameworks that we call “warranted” frameworks is a special case of our logic in the sense that Dung’s frameworks can be obtained from justification logic-based theories by focusing on a single aspect of attacks among justification logic arguments and Dung’s warranted frameworks always have multiple justification logic instantiations called “realizations”. We first define a new justification logic that relies on operational semantics for default logic. One of the key features that is absent in standard justification logics is the possibility to weigh different epistemic reasons or pieces of evidence that might conflict with one another. To amend this, we develop a semantics for “defeaters”: conflicting reasons forming a basis to doubt the original conclusion or to believe an opposite statement. This enables us to formalize non-monotonic justifications that prompt extension revision already for normal default theories. Then we present our logic as a system for abstract argumentation with structured arguments. The format of conflicting reasons overlaps with the idea of attacks between arguments to the extent that it is possible to define all the standard notions of argumentation framework extensions. Using the definitions of extensions, we establish formal correspondence between Dung’s original argumentation semantics and our operational semantics for default theories. One of the results shows that the notorious attack cycles from abstract argumentation cannot always be realized as justification logic default theories. (shrink)

We explore the relationship between argument and narrative with reference to parables. Parables are typically thought to convey a message. In examining a parable, we can ask what that message is, whether the story told provides reasons for the message, and whether those reasons are good reasons. In exploring these questions, we employ as an inves-tigative technique the strategy of reconstructing parables as argu-ments. We then proceed to con-sider the cogency of those argu-ments. One can offer arguments through narratives and, (...) in particu-lar, through parables, but that do-ing so likely brings more risks than benefits, from an epistemic point of view. (shrink)

I highlight a neglected but striking phenomenological fact about our experiences: they have a pervasively spatial character. Specifically, all (or almost all) phenomenal qualities – roughly, the introspectible, philosophically puzzling properties that constitute ‘what it’s like’ to have an experience – introspectively seem instantiated in some kind of space. So, assuming a very weak charity principle about introspection, some phenomenal qualities are instantiated in space. But there is only one kind of space – the ordinary space occupied by (...) familiar objects. And the only objects appropriately located in ordinary space are outside the subject’s mind. This entails experiential externalism, the view that at least one phenomenal quality is instantiated outside the subject’s mind. Experiential externalism is incompatible with many leading theories of experience, including certain mental paint theories; some forms of representationalism; paradigmatic versions of sense-datum theory; and views on which no phenomenal qualities are instantiated. My argument is structurally similar to familiar arguments based on the ‘transparency of experience.’ However, I suggest, phenomenological intuitions about spatiality are considerably more stable than phenomenological intuitions about transparency. For many philosophers, transparency intuitions fade markedly with respect to non-standard experiences, including experiences associated with blurry or double vision. But spatiality intuitions remain robust even for these experiences. Thus, spatiality intuitions should be more dialectically effective than transparency intuitions for supporting experiential externalism. (shrink)

Various claims have been made, recently, that Darwin's argumentation in the Origin instantiates and so supports some general philosophical proposal about scientific theorizing, for example, the "semantic view". But these claims are grounded in various incorrect analyses of that argumentation. A summary is given here of an analysis defended at greater length in several papers by the present author. The historical and philosophical advantages of this analysis are explained briefly. Darwin's argument comprises three distinct evidential cases on behalf (...) of natural selection, cases, that is, for its existence, its adequacy and its responsibility. Theorizing, today, about evolution by natural selection involves a similar structure of evidential and explanatory concerns. (shrink)

This paper investigates whether empirical findings on how humans evaluate arguments in reinstatement cases support the ‘fewer attackers is better’ principle, incorporated in many current gradual notions of argument acceptability. Through three variations of an experiment, we find that (1) earlier findings that reinstated arguments are rated lower than when presented alone are replicated, (2) ratings at the reinstated stage are similar if all arguments are presented at once, compared to sequentially, and (3) ratings are overall higher if participants are (...) provided with the relevant theory, while still instantiating imperfect reinstatement. We conclude that these findings could at best support a more specific principle ‘being unattacked is better than attacked’, but alternative explanations cannot yet be ruled out. More generally, we highlight the danger that experimenters in reasoning experiments interpret examples differently from humans. Finally, we argue that more justification is needed on why, and how, empirical findings on how humans argue can be relevant for normative models of argumentation. (shrink)

The task of data collection is becoming routine in many disciplines and this results in increased availability of data. This routinely collected data provides a valuable opportunity for analysis with a view to support evidence based decision making. In order to confidently leverage the data in support of decision making the most appropriate statistical method needs to be selected, and this can be difficult for an end user not trained in statistics. This paper outlines an application of argumentation to (...) support the analysis of clinical data, that uses Extended Argumentation Frameworks in order to reason with the meta-level arguments derived from preference contexts relevant to the data and the analysis objective of the end user. We outline a formalisation of the argument scheme for statistical model selection, its critical questions and the structure of the knowledge base required to support the instantiation of the arguments and meta-level arguments through the use of Z notation. This paper also describes the prototype implementation of argumentation for statistical model selection based on the Z specification outlined herein. (shrink)

In this paper, we propose an argumentation formalism that allows for both deductive and abductive argumentation, where ‘deduction’ is used as an umbrella term for both defeasible and strict ‘forward’ inference. Our formalism is based on an extended version of our previously proposed information graph formalism, which provides a precise account of the interplay between deductive and abductive inference and causal and evidential information. In the current version, we consider additional types of information such as abstractions which allow (...) domain experts to be more expressive in stating their knowledge, where we identify and impose constraints on the types of inferences that may be performed with the different types of information. A new notion of attack is defined that captures a crucial aspect of abductive reasoning, namely that of competition between abductively inferred alternative explanations. Our argumentation formalism generates an abstract argumentation framework and thus allows arguments to be formally evaluated. We prove that instantiations of our argumentation formalism satisfy key rationality postulates. (shrink)

A physicalist holds, in part, that what properties are instantiated depends on what physical properties are instantiated; a physicalist thinks that mental properties, for example, are instantiated in virtue of the instantiation of physical “realizer” properties. One issue that arises in this context concerns the relationship between the “causal powers” of instances of physical properties and instances of dependent properties, properties that are instantiated in virtue of the instantiation of physical properties. After explaining the significance of (...) this issue, I evaluate two core lines of thought that have been advanced in favor of Subset Inheritance, the view that instances of dependent properties typically have some, but not all, of the powers of physical realizers, and do not have any powers that are not also powers of physical realizers. The first argument that I address turns on our intuitive reactions to certain cases; the second appeals to the phenomenon of multiple realization. I argue that neither line of thought succeeds, and thus that insofar as we grant that an instance of a dependent property inherits some of the powers of its physical realizer, defenders of subset inheritance have not provided a compelling reason to think that it will not inherit all of the powers of its physical realizer. (shrink)

Firewalls are an important tool in the assurance of network security. Packet filtering firewalls are configured by providing a set of rules that identify how to handle individual data packets that arrive at the firewall. In large firewall configurations, conflicts may arise between these rules. Argumentation provides a way of handling conflicts such that their origin is illuminated, and hence can help a system administrator understand the effects of a given configuration. To show how argumentation might help in (...) this domain we examine the use of a system of metalevel argumentation for firewall configuration, showing how it makes conflicts and their origins clear, and showing how different instantiations of a metalevel argumentation system provide alternative ways to resolve conflicts. (shrink)

This paper discusses a somewhat neglected reading of the second chapter of Nāgārjuna’s Mūlamadhyamakakārikā, arguing that the main focus of a crucial part is a particular theory of properties and their relation to individuals they instantiate, rather than the refutation of specific assumptions about the nature of space and time. Some of Nāgārjuna’s key arguments about motion should be understood as argument templates in which notions other than mover, motion, and so forth could be substituted. The remainder of the discussion (...) of motion does not serve quasi-Zenonian purposes either but uses motion as a principal example of change and considers the soteriological problems of the subject moving (gati) through transmigratory existence (saṃsāra). I attempt to show how this interpretation coheres with Nāgārjuna’s overall philosophical project. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 37.1 (2004) 42-71 [Access article in PDF] Narrative as Argument in Indian Philosophy: The Astavakra Gita as Multivalent Narrative Scott R. Stroud Department of Philosophy Temple University Indian philosophy has often been described as radically different in nature than Western philosophy due to its frequent use of narrative structure. By employing poetic elements in their use of language, such texts attempt to convey deep metaphysical truths (...) and philosophical positions about reality that are in many cases quite different from Western ideas (Babbili 1997). Often, these ways of conveying truths are an integral part of that truth. One particularly useful form is narrative, taking instantiations such as a dialogue between characters. Philosophical dialogues such as the Bhagavad Gita and the Astavakra Gita (also known as the Astavakra Samhita ) use a portrayed conversation involving a guru or deity to convey didactic lessons and values to the receptive audience, both ancient and modern. As texts such as the Bhagavad Gita gain in popularity and circulation in the Western world (Minor 1982; Paine 1998; Sharpe 1985), philosophical and rhetorical inquiry must be extended to explain how these texts function in an argumentative philosophical context.Stroud (2002a, 2002b) has advanced the idea that such ancient Indian narratives argue through the use of contradictions and conflicting value structures;1 he labels such texts as multivalent narratives since their use of contradictory value structures compel audience members to reconstruct the narrative's message and allow for the acceptance of novel views. Multivalent narratives are to be distinguished from polysemic narratives (Fiske 1986) in that the latter concern different audience members finding a preferred position from the ambiguous story. Polysemic narratives involve the difference in meaning of the same story to different auditors. Condit criticizes this notion of polysemic narratives and advances her own concept of polyvalent narratives. The concept of a polyvalent narrative involves different auditors understanding the same story in similar ways, but differing in how they evaluate its message. Condit's research with a popular television [End Page 42] show and two students from radically different backgrounds on abortion finds that they understood what occurred in a very similar fashion; they differed in that they "disagree[d] about the valuation of those denotations to such a degree that they produce[d] noticeably different interpretations" (1989, 106). Thus, the auditors differ as to their response to a certain story and how it treats their own cherished values. Stroud (2002a) provides a thorough justification as to why the concepts of polysemic and polyvalent narratives do not capture what can be called multivalent narratives. The important factor in distinguishing these three concepts is that the third involves contradictions at the level of values within a text and the reader's necessitated activity of trying to synthesize or reconcile such contradictions. It is this activity that is the hallmark of multivalent narratives.This employment of multivalent narrative offers a challenge to familiar Western conceptions of argumentative discourse and demands further investigation. This study explores the ways a particular text, the Astavakra Gita, argues its philosophical positions to its audience of potential "pupils."2 Using the insights provided by theories of narrative and reader-response theory, I will argue that this text advances its claims not through overt syllogism or validity claim redemption, but through textual indeterminacy between the audience's disposition and the foregrounded theme of non-individuation in the text. This tension, increased by certain textual devices, results in consistency building by the audience, which enables the transcendence of these two viewpoints (reader and text); it is this experience, not claim, that the Astavakra Gita seems to be advancing to any given audience.In order to explore this interpretation of this text and its argumentative relationship to an audience, insights from both literary studies and rhetorical theory must be used in laying a foundation. The work of Wolfgang Iser (1980, 1989, 1993) and Walter Fisher (1987) will assume roles of particular importance in this endeavor. Iser's theory of aesthetic response provides a useful description of the phenomenological process of reading such a... (shrink)