The paper considers contemporary models of presumption in terms of their ability to contribute to a working theory of presumption for argumentation. Beginning with the Whatelian model, we consider its contemporary developments and alternatives, as proposed by Sidgwick, Kauffeld, Cronkhite, Rescher, Walton, Freeman, Ullmann-Margalit, and Hansen. Based on these accounts, we present a picture of presumptions characterized by their nature, function, foundation and force. On our account, presumption is a modal status that is attached to a claim and has the (...) effect of shifting, in a dialogue, a burden of proof set at a local level. Presumptions can be analysed and evaluated inferentially as components of rule-based structures. Presumptions are defeasible, and the force of a presumption is a function of its normative foundation. This picture seeks to provide a framework to guide the development of specific theories of presumption. (shrink)
In “The logic of deep disagreements” (Informal Logic, 1985), Robert Fogelin claimed that there is a kind of disagreement – deep disagreement – which is, by its very nature, impervious to rational resolution. He further claimed that these two views are attributable to Wittgenstein. Following an exposition and discussion of that claim, we review and draw some lessons from existing responses in the literature to Fogelin’s claims. In the final two sections (6 and 7) we explore the role reason can, (...) and sometimes does, play in the resolution of deep disagreements. In doing this we discuss a series of cases, mainly drawn from Wittgenstein, which we take to illustrate the resolution of deep disagreements through the use of what we call “rational persuasion.” We conclude that, while the role of argumentation in “normal” versus “deep” disagreements is characteristically different, it plays a crucial role in the resolution of both. (shrink)
This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and (...) may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align. (shrink)
Working within the broad lines of general consensus that mark out the core features of John Stuart Mill’s (1806–1873) logic, as set forth in his A System of Logic (1843–1872), this chapter provides an introduction to Mill’s logical theory by reviewing his position on the relationship between induction and deduction, and the role of general premises and principles in reasoning. Locating induction, understood as a kind of analogical reasoning from particulars to particulars, as the basic form of inference that is (...) both free-standing and the sole load-bearing structure in Mill’s logic, the foundations of Mill’s logical system are briefly inspected. Several naturalistic features are identified, including its subject matter, human reasoning, its empiricism, which requires that only particular, experiential claims can function as basic reasons, and its ultimate foundations in ‘spontaneous’ inference. The chapter concludes by comparing Mill’s naturalized logic to Russell’s (1907) regressive method for identifying the premises of mathematics. (shrink)
Recent work on conditional reasoning argues that denying the antecedent [DA] and affirming the consequent [AC] are defeasible but cogent patterns of argument, either because they are effective, rational, albeit heuristic applications of Bayesian probability, or because they are licensed by the principle of total evidence. Against this, we show that on any prevailing interpretation of indicative conditionals the premises of DA and AC arguments do not license their conclusions without additional assumptions. The cogency of DA and AC inferences rather (...) depends on contingent factors extrinsic to, and independent of, what is asserted by DA and AC arguments. arguments do not license their conclusions without additional assumptions. The cogency of DA and AC inferences rather depends on contingent factors extrinsic to, and independent of, what is asserted by DA and AC arguments. (shrink)
This paper argues against the priority of pure, virtue-based accounts of argumentative norms [VA]. Such accounts are agent-based and committed to the priority thesis: good arguments and arguing well are explained in terms of some prior notion of the virtuous arguer arguing virtuously. Two problems with the priority thesis are identified. First, the definitional problem: virtuous arguers arguing virtuously are neither sufficient nor necessary for good arguments. Second, the priority problem: the goodness of arguments is not explained virtuistically. Instead, being (...) excellences, virtues are instrumental in relation to other, non-aretaic goods—in this case, reason and rationality. Virtues neither constitute reasons nor explain their goodness. Two options remain for VA: either provide some account of reason and rationality in virtuistic terms, or accept them as given but non-aretaic goods. The latter option, though more viable, demands the concession that VA cannot provide the core norms of argumentation theory. (shrink)
Visual arguments can seem to require unique, autonomous evaluative norms, since their content seems irreducible to, and incommensurable with, that of verbal arguments. Yet, assertions of the ineffability of the visual, or of visual-verbal incommensurability, seem to preclude counting putatively irreducible visual content as functioning argumentatively. By distinguishing two notions of content, informational and argumentative, I contend that arguments differing in informational content can have equivalent argumentative content, allowing the same argumentative norms to be rightly applied in their evaluation.
This paper explicates an account of argumentative rationality by articulating the common, basic idea of its nature, and then identifying a collection of assumptions inherent in it. Argumentative rationality is then contrasted with dual-process theories of reasoning and rationality prevalent in the psychology of reasoning. It is argued that argumentative rationality properly corresponds only with system-2 reasoning in dual-process theories. This result challenges the prescriptive force of argumentative norms derives if they derive at all from their descriptive accuracy of our (...) cognitive capacities. In response, I propose an activity-based account of reasoning which retains the assumptions of argumentative rationality while recontextualizing the relationship between reasoning as a justificatory activity and the psychological states and processes underlying that activity. (shrink)
In a series of recent papers beginning with their “Splitting a difference of opinion: The shift to negotiation” Jan Albert van Laar and Erik Krabbe claim that it is sometimes reasonable to shift from a critical discussion to a negotiation in order to settle a difference of opinion. They argue that their proposal avoids the fallacies of bargaining and middle ground. Against this permissive policy for shifting to negotiation, we argue that the motivating reasons for such shifts typically fail, and (...) that the permissive policy avoids neither fallacy while structurally incentivizing two types of strategic maneuvering that constitute rational and argumentative hazards: argumentative overcharge and abandonment of discussion. (shrink)
This paper examines the adequacy of commitment change, as a measure of the successful resolution of a difference of opinion. I argue that differences of opinion are only effectively resolved if commitments undertaken in argumentation survive beyond its conclusion and go on to govern an arguer’s actions in everyday life, e.g., by serving as premises in her practical reasoning. Yet this occurs, I maintain, only when an arguer’s beliefs are changed, not merely her commitments.
Standards and norms for reasoning function, in part, to manage epistemic risk. Properly used, modal qualifiers like presumably have a role in systematically managing epistemic risk by flagging and tracking type-specific epistemic merits and risks of the claims they modify. Yet, argumentation-theoretic accounts of presumption often define it in terms of modalities of other kinds, thereby failing to recognize the unique risk profile of each. This paper offers a stipulative account of presumption, inspired by Ullmann-Margalit, as an inferentially generated modal (...) qualifier, “presumably, p,” distinguishing it from other, particularly epistemic modalities, e.g., standing commitments, assumptions, assertions, suppositions, hypotheses, and defeasible claims. By avoiding the tranching of inferential instruments of qualitatively different bona fides and risk profiles, this account provides a more accurate risk-rating system that better manages epistemic risk in inference, as well as contributing to the normative theory of the operation of presumption in reasoning and argument. (shrink)
Adversariality in argumentation is typically theorized as inhering in, and applying to, the interactional roles of proponent and opponent that arguers occupy. This paper considers the kinds of adversariality located in the conversational roles arguers perform while arguing—specifically listening. It begins by contending that the maximally adversarial arguer is an arguer who refuses to listen to reason by refusing to listen to another’s reasons. It proceeds to consider a list of lousy listeners in order to illustrate the variety of ways (...) that the conversational role of listener can be performed adversarially. Because conversational roles, while not adversarial by nature, can be enacted adversarially, arguers are properly subject to praise and blame for their performances of these roles. Thus, the paper concludes, argumentation theory stands in need of an articulated normative vocabulary and theory to codify, apply, explain, and justify the norms of listening governing, guiding, and appraising arguers’ performances of listening in argumentation. (shrink)
This paper begins a working through of Blair’s (2001) theoretical agenda concerning argumentation schemes and their attendant critical questions, in which we propose a number of solutions to some outstanding theoretical issues. We consider the classification of schemes, their ultimate nature, their role in argument reconstruction, their foundation as normative categories of argument, and the evaluative role of critical questions.We demonstrate the role of schemes in argument reconstruction, and defend a normative account of their nature against specific criticisms due to (...) Pinto (2001). Concerning critical questions, we propose an account on which they are founded in the R.S.A. cogency standard, and develop an account of the relationship between critical questions and burden of proof. Our ultimate aim is to initiate a reconciliation between dialectical and informal logic approaches to the schemes. (shrink)
Typically, common knowledge is taken as grounds for the acceptability of a claim, while appeals to popularity are seen as fallacious attempts to support a claim. This paper poses the question of whether there is any categorical difference between appeals to common knowledge and appeals to popular opinion as argumentative moves. In answering this question, I argue that appeals to common knowledge do not, on their own, provide adequate grounds for a claim’s acceptability.
Disputational models of argumentation have been criticized as introducing adversariality into argumentation by mistakenly conceiving of it as minimally adversarial, and, in doing so, structurally incentivizing ancillary adversariality. As an alternative, non-adversarial models of argumentation like inquiry have been recommended. In this article I defend disputational, minimally adversarial models of disagreement-based argumentation. First, I argue that the normative kernel of minimal adversariality is properly located in the normative fabric of disagreement, not our practices of disputation. Thus, argumentation’s minimal adversariality is (...) a hereditary, rather than an acquired, trait. Second, I show how attempts to model disagreement-based argumentation non-adversarially, as co-inquiry, misrepresent the normative commitments of disagreers. Indeed, such attempts backfire in their efforts to make argumentation less adversarial, by removing the normative, discursive mechanisms by which we may hold each other to rational account for our commitments. Finally, I show how regulative models of disputation, like the Pragma-Dialectical critical discussion, are designed to minimize ancillary adversariality thereby preventing its escalation. (shrink)
This paper examines the views of Fogelin, Woods, Johnstone, etc., concerning deep disa-greements, force-five standoffs, philosophical controversies, etc. My approach is to reconstruct their views and critiques of them as meta-arguments, and to elaborate the meta-argumentative aspects of radical disa-greements. It turns out that deep disagreements are resolvable to a greater degree than usually thought, but only by using special principles and practices, such as meta-argumentation, ad hominem argumentation, Ramsey’s principle, etc.
This paper considers the question of whether Mill's account of the nature and justificatory foundations of deductive logic is psychologistic. Logical psychologism asserts the dependency of logic on psychology. Frequently, this dependency arises as a result of a metaphysical thesis asserting the psychological nature of the subject matter of logic. A study of Mill's System of Logic and his Examination reveals that Mill held an equivocal view of the subject matter of logic, sometimes treating it as a set of psychological (...) processes and at other times as the objects of those processes. The consequences of each of these views upon the justificatory foundations of logic are explored. The paper concludes that, despite his providing logic with a prescriptive function, and despite his avoidance of conceptualism, Mill's theory fails to provide deductive logic with a justificatory foundation that is independent of psychology. (shrink)
Deductivism has been variously presented as an evaluative thesis and as an interpretive one. I argue that deductivism fails as a universal evaluative thesis, and as such that its value as an interpretive thesis must be supported on other grounds. As a reconstructive strategy, deductivism is justified only on the grounds that an arguer is, or ought to be, aiming at the deductive standard of evidence. As such, the reconstruction of an argument as deductive must be supported by contextual and (...) situational factors including facts about the arguer. Further, the plausibility of deductivism as a normative thesis is not tied to its plausibility as a descriptive or interpretive thesis. (shrink)
The standard account of denying the antecedent (DA) is that it is a deductively invalid form of argument, and that, in a conditional argument, to argue from the falsity of the antecedent to the falsity of the consequent is always fallacious. In this paper, we argue that DA is not always a fallacious argumentative strategy. Instead, there is a legitimate usage of DA according to which it is a defeasible argument against the acceptability of a claim. The dialectical effect of (...) denying the antecedent is to shift the burden of proof back to the original proponent of a claim. We provide a model of this non-fallacious usage which is built upon pragmatic models of argumentation. (shrink)
Jan Albert van Laar and Erik Krabbe’s paper “Splitting a difference of opinion” studies an important type of dialogue shift, namely that from a deliberation dialogue over action or policy options where critical and persuasive argumentation is exchanged about the rational acceptability of the policy options proposed by various parties, to a negotiation dialogue where agreement is reached by a series of compromises, or trade-offs, on the part of each side in the disagreement.
While courts depend on expert opinions in reaching sound judgments, the role of the expert witness in legal proceedings is associated with a litany of problems. Perhaps most prevalent is the question of under what circumstances should testimony be admitted as expert opinion. We review the changing policies adopted by American courts in an attempt to ensure the reliability and usefulness of the scientific and technical information admitted as evidence. We argue that these admissibility criteria are best seen in a (...) dialectical context as a set of critical questions of the kind commonly used in models of argumentation. (shrink)
Robert Fogelin argued that the efficacy of our acts of reasons-giving depends on the normalcy of our discourse—to the extent that discourse is not normal disagreements occurring in it are deep; and to the extent that disagreements are deep, they are not susceptible to rational resolution. Against this, Maurice Finocchiaro argues that meta-argumentation can contribute to the rational resolution of disagreements having depth. Drawing upon a competency view of reasons-giving, this article conducts an inventory and audit of meta-argumentation’s resolution resources (...) for disagreements having depth. It concludes that, because Finocchiaro mischaracterizes the relationship between meta-argumentation and normalcy in the underlying discourse, he systematically overstates the rational resolution value of meta-argumentation. To the extent that meta-argumentation can contribute to the rational resolution of disagreements, those disagreements are normal, not deep. According to the competency view, the only way to resolve depth in disagreement is to first re-establish its normalcy. (shrink)
By examining particular cases of belief perseverance following the undermining of their original evidentiary grounds, this paper considers two theories of rational belief revision: foundation and coherence. Gilbert Harman has argued for coherence over foundationalism on the grounds that the foundations theory absurdly deems most of our beliefs to be not rationally held. A consequence of the unacceptability of foundationalism is that belief perseverance is rational. This paper defends the intuitive judgement that belief perseverance is irrational by offering a competing (...) explanation of what goes on in cases like the debriefing paradigm which does not rely upon foundationalist principles but instead shows that such cases are properly viewed as instances of positive undermining of the sort described by the coherence theory. (shrink)
The paper reports on a Socratic exercise that introduces participants to the norm of rational entitlement, as distinct from political entitlement, and the attendant norm of rational responsibility. The exercise demonstrates that, because participants are not willing to exchange their own opinion at random for another differing opinion to which the owner is, by the participants’ own admission, entitled, they treat their entitlement to their own opinion differently, giving it a special status. This gives rise to rational obligations such as (...) the obligation to provide reasons, and a willingness to risk those opinions to the force of the better reason. (shrink)
This brief editorial considers a special issue of Argumentation edited by Jens Kjeldsen on visual, multimodal argumentation. It provides a commentary on important advances on interpretative problems such as the propositionality of argument, the reducibility of images to words, whether argument products are primarily cognitive artifacts, and the nature of a modality of argument. Concerning the project of argument appraisal, it considers whether visual arguments call for a revision of our normative, evaluative apparatus.
Our meta-argumentative vocabulary supplies the conceptual tools used to reflectively analyse, regulate, and evaluate our argumentative performances. Yet, this vocabulary is susceptible to misunderstanding and abuse in ways that make possible new discursive mistakes and pathologies. Thus, our efforts to self-regulate our reason-transacting practices by articulating their norms makes possible new ways to violate and flout those very norms. Scott Aikin identifies the structural possibility of this vicious feedback loop as the Owl of Minerva Problem. In the spirit of a (...) shared concern for the flourishing or our rational, argumentative practices, this paper approaches the Owl of Minerva Problem from a vantage point that, by comparison with Aikin’s, affords perspectives that are more pessimistic in some aspects and more optimistic in others. Pessimistically, the problem at the root of the weaponization of our meta-argumentative vocabulary is motivational, not structural. Its motivational nature explains its resistance to the normal repertoire of reparative argumentative maneuvers, as well as revealing a profound and deeply entrenched misunderstanding of the connection between our reasons-transacting practices and the goods achievable within them. Optimistically, in the absence of this motivational problem, the misunderstandings and errors made possible by our meta-argumentative vocabularies are amenable to remedy by familiar techniques of discursive instruction and repair. More optimistically, even though our meta-argumentative vocabularies are generated only retrospectively, they can be used prospectively, thereby making possible an aspirational motivation resulting in a virtuous cycle of increasingly autonomous normative self-regulation. Properly harnessed, the Owl of Minerva releases the Lark of Arete. (shrink)
This article examines the development of Russell's treatment of propositions, in relation to the topic of psychologism. In the first section, we outline the concept of psychologism, and show how it can arise in relation to theories of the nature of propositions. Following this, we note the anti-psychologistic elements of Russell's thought dating back to his idealist roots. From there, we sketch the development of Russell's theory of the proposition through a number of its key transitions. We show that Russell, (...) in responding to a variety of different problems relating to the proposition, chose to resolve these problems in ways that continually made concessions to psychologism. (shrink)
Corroborative evidence can have a dual function in argument whereby not only does it have a primary function of providing direct evidence supporting the main conclusion, but it also has a secondary, bolstering function which increases the probative value of some other piece of evidence in the argument. It has been argued (Redmayne, 2000) that this double function gives rise to the fallacy of double counting whereby the probative weight of evidence is overvalued by counting it twice. Walton has proposed (...) several models of corroborative evidence, each of which seems to accept the fallaciousness of double counting thereby seeming to deny the dual function of corroborative evidence. Against this view, I argue that the bolstering effect is legitimate, and can be explained by recourse to inference to the best explanation. (shrink)
This chapter situates Mill’s System of Logic (1843/1872) in the context of some of the meta-logical themes and disputes characteristic of the 19th century as well as Mill’s empiricism. Particularly, by placing the Logic in relation to Whately’s (1827) Elements of Logic and Mill’s response to the “great paradox” of the informativeness of syllogistic reasoning, the chapter explores the development of Mill’s views on the foundation, function, and the relation between ratiocination and induction. It provides a survey of the Mill-Whewell (...) debate on the nature of induction, Mill’s account of putatively a priori disciplines such as the science of number, and Frege’s criticisms of the Logic as psychologistic. (shrink)
This paper responds to Kauffeld’s 2009 OSSA paper, considering the adequacy of his “commitment-based” approach to “ordinary presumptive practices” to sup-ply an account of presumption fit for general application in normative theories of argument. The central issue here is whether socially-grounded presumptions are defeasible in the right sorts of ways so as to pro-duce “truth-tropic” presumptive inferences.
In this paper we show how dialogue-based theories of argumentation can contribute to the construction of effective systems of dispute resolution. Specifically we consider the role of persuasion in online dispute resolution by showing how persuasion dialogues can be functionally embedded in negotiation dialogues, and how negotiation dialogues can shift to persuasion dialogues. We conclude with some remarks on how persuasion dialogues might be modelled is such a way as to allow them to be implemented in a mechanical or computerized (...) system of dialogue or dialogue management. (shrink)
Knowledge plays an important role in argumentation. Yet, recent work shows that standard conceptions of knowledge in epistemology may not be entirely suitable for argumentation. This paper explores the role of knowledge in argumentation, and proposes a notion of knowledge that promises to be more suitable for argumentation by taking account of: its dynamic nature, the defeasibility of our commitments, and the non-monotonicity of many of the inferences we use in everyday reasoning and argumentation.
Analogical reasoning projects a property taken to hold of something or things to something else on the basis of just those similarities premised in the analogy. Standard similarity-based accounts of analogical reasoning face the question: Under what conditions does a collection of similarities sufficiently warrant analogical projection? One answer is: When a thing’s having the premised similarities somehow determines its having the projected property. Standardly, this answer has been interpreted as claiming that a formally defined determination relation exists between the (...) variables of which the determining properties are values and the variable of which the determined property is a value. This paper supplies another answer: Analogical projection is warranted when an item’s having the projected property is grounded in its having the premised similarities. Drawing on the metaphysics of grounding, we propose a model of grounded analogy on which analogical reasoning is valid under metaphysical necessity. Our model thus provides one answer to John Stuart Mill’s question of how analogical reasoning based on limited information about a single source case can provide an indefeasible justification for analogical projection. Once a relation of total grounding is ascertained to hold between some similarities and the projected property, no other properties bear on the projectability of the projected property from the source to the target. (shrink)
Corroborative evidence has a dual function in argument. Primarily, it functions to provide direct evidence supporting the main conclusion. But it also has a secondary, bolstering function which increases the probative value of some other piece of evidence in the argument. This paper argues that the bolstering effect of corroborative evidence is legitimate, and can be explained as counter–rebuttal achieved through inference to the best explanation. A model (argument diagram) of corroborative evidence, representing its structure and operation as a schematic (...) pattern of defeasible argument is also supplied. In addition to explaining the operation and theoretical foundation of corroborative evidence, the model facilitates the correct analysis and guides the evaluation (assessment and critique) of corroborative evidence as it occurs in argument. (shrink)
The paper addresses the manner in which the theory of Coalescent Argumentation [CA] has been received by the Argumentation Theory community. I begin (section 2) by providing a theoretical overview of the Coalescent model of argumentation as developed by Michael A. Gilbert (1997). I next engage the several objections that have been raised against CA (section 3). I contend that objectors to the Coalescent model are not properly sensitive to the theoretical consequences of the genuinely situated nature of argument. I (...) conclude (section 4) by suggesting that the resolution to the dispute between Gilbert and his objectors hinges on the outcome of several foundational theoretical questions identified over the course of the paper. (shrink)
One of the central tasks of a theory of argumentation is to supply a theory of appraisal: a set of standards and norms according to which argumentation, and the reasoning involved in it, is properly evaluated. In their most general form, these can be understood as rational norms, where the core idea of rationality is that we rightly respond to reasons by according the credence we attach to our doxastic and conversational commitments with the probative strength of the reasons we (...) have for them. Certain kinds of rational failings are so because they are manifestly illogical – for example, maintaining overtly contradictory commitments, violating deductive closure by refusing to accept the logical consequences of one’s present commitments, or failing to track basing relations by not updating one’s commitments in view of new, defeating information. Yet, according to the internal and empirical critiques, logic and probability theory fail to supply a fit set of norms for human reasoning and argument. Particularly, theories of bounded rationality have put pressure on argumentation theory to lower the normative standards of rationality for reasoners and arguers on the grounds that we are bounded, finite, and fallible agents incapable of meeting idealized standards. This paper explores the idea that argumentation, as a set of practices, together with the procedures and technologies of argumentation theory, is able to extend cognition such that we are better able to meet these idealized logical standards, thereby extending our responsibilities to adhere to idealized rational norms. (shrink)
This paper considers the probative burdens of proposing action or policy options in deliberation dialogues. Do proposers bear a burden of proof? Building on pioneering work by Douglas Walton, and following on a growing literature within computer science, the prevailing answer seems to be “No.” Instead, only recommenders—agents who put forward an option as the one to be taken—bear a burden of proof. Against this view, we contend that proposers have burdens of proof with respect to their proposals. Specifically, we (...) argue that, while recommenders that Φ bear a burden of proof to show that □Φ, proposers that Φ have a burden of proof to show that ◇Φ. A burden of proposing may be defined as, which reads: Those who propose that we might Φ are obliged, if called upon, to show that Φ is possible in any of four ways which we call worldly, deontic, instrumental, and practical. So understood, burdens of proposing satisfy the standard formal definition of burden of proof. (shrink)
ABSTRACT This article argues that Quine's holistic and naturalized semantics provides an inadequate account of the foundations of logical expressions and misrepresents the internal structure of theories. By considering a Quinean model of theoretical revision, I identify the status and foundation holism provides to the propositions of logic. I contend that a central tenet of Quinean holism—the Revisability Doctrine—cannot be held consistently, and that the inconsistencies surrounding it mark a series of pervasive errors within naturalized holism. In response, I propose (...) that semantic theories must reflect the different linguistic functions of different types of expressions and the specific relationships that individual concepts within a theory or language have to one another. (shrink)
A problem for dialogue models of argumentation is to specify a set of conditions under which an opponent’s claims, offered in support of a standpoint under dispute, ought to be challenged. This project is related to the issue of providing a set of acceptability conditions for claims made in a dialogue. In this paper, we consider the conditions of suspicion and trust articulated by Jacobs (Alta, 2003), arguing that neither are acceptable as general conditions for challenge. We propose a third (...) condition that attempts to mark a middle ground between suspicion and trust. (shrink)
Corroborative evidence may be understood as having two epistemic effects: a primary effect by which it offers direct evidence for some claim, and a secondary effect by which it bolsters the appraised probative, or evidential, value of some other piece of evidence for that claim. This paper argues that the bolstering effect of corroborative evidence is epistemically legitimate because corroboration provides a reason to count the belief based on the initial evidence as sensitive to, and safe from, defeat in a (...) way that it was not previously recognized to be. Discovering that our initial evidence tracks the truth in a way we previously did not recognize provides a reason to positively reappraise the probative value of that evidence. The final section of the paper relates the proposed sensitivity- and safety-based account of corroboration to an explanation-based account. (shrink)
While defeasibility in legal reasoning has been the subject of recent scholarship, it has yet to be studied in the context of judicial opinion. Yet, being subject to appeal, judicial decisions can default for a variety of reasons. Prakken (2001) argued that the defeasibility affecting reasoning involved in adversarial legal argumentation is best analysed as procedural rather than logical. In this paper we argue that the defeasibility of ratio decendi is similarly best explained and modeled in a procedural and dialectical (...) framework. We propose that appeals are best understood as meta-dialogues about the reasoned dialogue occurring in the initial trial. (shrink)
Toulmin’s DWC model recognizes a plurality of argument cultures through the thesis of field dependency: that the normative features of arguments vary from one field to the next. Yet, little consensus exists concerning the nature and foundations of argument fields. This paper explores the question of whether Toulminian fields have any useful role to play in the epistemic evaluation of arguments.