Reasoning, Misc

In the last thirty years, a relatively large group of cognitive scientists have begun characterising the mind in terms of two distinct, relatively autonomous systems. To account for paradoxes in empirical results of studies mainly on reasoning, Dual Process Theories were developed. Such Dual Process Theories generally agree that System 1 is rapid, automatic, parallel, and heuristic-based and System 2 is slow, capacity-demanding, sequential, and related to consciousness. While System 2 can still be decently understood from a traditional cognitivist approach, (...) I will argue that it is essential for System 1 processing to be comprehended in an Embodied Embedded approach to Cognition. (shrink)

This paper develops concepts and procedures for the evaluation of complex debates. They provide means for answering such questions as whether a thesis has to be considered as proven or disproven in a debate or who carries a burden of proof. While being based on classical logic, this framework represents an (argument-based) approach to non-monotonic, or defeasible reasoning. Debates are analysed as dialectical structures, i.e. argumentation systems with an attack- as well as a support-relationship. The recursive status assignment over the (...) arguments is conditionalised on proponents in a debate. The problem of multiple status assignments arising on circular structures is solved by showing that uniqueness can be guaranteed qua reconstruction of a debate. The notion of burden of proof as well as other discursive aims rational proponents pursue in a debate is defined within the framework. (shrink)

This article is a general introduction to the psychology of reasoning. Specifically, it focuses on the dual process theory of human cognition. Proponents of the said two-system view hold that human cognition involves two processes (viz., System 1 and System 2). System 1 is an automatic, intuitive thinking process where judgments and reasoning rely on fast thinking and ready-to-hand data. On the other hand, System 2 is a slow, logical cognitive process where our judgments and reasoning rely on reflective, careful (...) analysis and data evaluation. Supposedly, these two cognitive processes are at play in every thinking task, and they sometimes work together and sometimes go against each other. (shrink)

On the approach to discussions of policy choices that treats such discussions as instances of issue-processing, the joint use of the logic of questions and the logic of rules gives precise formulation to two sorts of issues. To one sort of issue belong issue-circumscribing questions; to another sort, issues-simplicter, which consist of disjunctions of policy proposals – so many proposed social rules – that are answers, in the case of each disjunction, to a given issue-circumscribing question. Work in pragma-dialectics can (...) take over the issue-processing approach; and by doing so add to the pragma-dialectical repertory further dimensions in the analysis of issues and in protocol-narratives of discussion. The analysis and narratives would now include accounts of how issue-circumscribing questions generate initial standpoints and how discussions sometimes end with compromises between standpoints. Further research questions follow about transformations of issues and the comparison of successive rounds of discussion. A narrative of one period of discussion during `the War on Drugs' in the United States illustrates these points. (shrink)

This paper addresses the extent to which quotidian cognition is like scientific inference by focusing on Jerry Fodor's famous analogy. I specifically consider and rebut a recent attempt made by Tim Fuller and Richard Samuels to deny the usefulness of Fodor's analogy. In so doing, I reveal some subtleties of Fodor's arguments overlooked by Fuller and Samuels and others. Recognizing these subtleties provides a richer appreciation of the analogy, allowing us to gain better traction on the issue concerning the extent (...) to which everyday cognition is like scientific inference. In the end, I propose that quotidian cognition is indeed like scientific inference, but not precisely in the way Fodor claims it is. (shrink)

A survey of contemporary philosophical and scientific literatures reveals that different authors employ the term ‘heuristic’ in ways that deviate from, and are sometimes inconsistent with, one another. Given its widespread use in philosophy and cognitive science generally, it is striking that there appears to be little concern for a clear account of what phenomena heuristics pick out or refer to. In response, I consider several accounts of ‘heuristic’, and I draw a number of distinctions between different sorts of heuristics (...) in order to make sense of various research programmes. I then develop a working characterization of ‘heuristic’ which is shown to be coherent and robust enough to serve as a kind within philosophy and cognitive science broadly. My intent is not to pursue a unified account of ‘heuristic’, but to highlight some features of certain kinds of heuristics that are important for theorizing about cognition in order to proceed with a science of the mind/brain. 1 Why We Need an Appropriate Characterization of ‘Heuristic’2 Inadequate Definitions2.1 A positive attempt2.2 Heuristics versus guaranteed correct outcomes3 A Taxonomy of Heuristics3.1 Stimulus-driven versus heuristic3.2 Perceptual versus cognitive heuristics3.3 Computational versus cognitive heuristics3.4 Methodological versus inferential heuristics3.5 Summary of distinctions4 Characterizing Cognitive Heuristics4.1 Heuristics as rules of thumb4.2 Beyond rules of thumb: exploiting information5 Concluding Remarks. (shrink)

Standard definitions of validity are designed to preserve truth from the premises to the conclusion. However, it seems possible to construct arguments that contain sentences in the imperative mood. Such sentences are incapable of being true or false, so the standard definitions cannot capture the validity of these imperative arguments. Bernard Williams offers an argument that imperative inference is impossible: two imperatives will always have different permissive presuppositions, so a speaker will have to change his mind before uttering a second (...) imperative, and so imperatives cannot ever be accumulated into a set of premises. I offer four objections to Williams’ argument: (1) Permissive presuppositions are analogous to conversational implicature, and so should be ignored when formulating imperative arguments. (2) There are other valid argument forms, which Williams does not consider, that do not suffer from different permissive presuppositions. (3) There are explanations for the change in permissive presuppositions in Williams’ example other than a change of mind, so the different permissive presuppositions do not have to prevent accumulation. Finally, (4) Williams accepts enough logical relations between imperatives (contradiction and a form of negation) for a definition of a valid imperative inference to follow naturally. (shrink)

We have noticed a pattern of arguments that exhibit a type of irrationality or a particular informal logical fallacy that is not fully captured by any existing fallacy. This fallacy can be explored through three examples where one misattributes a cause by focusing on a smaller portion of a larger set—specifically, the last or least known—and claiming that that cause holds a unique priority over other contributing factors for the occurrence of an event. We propose to call this fallacy the (...) “last straw fallacy” and will argue why these examples actually warrant a new logical name. Finally, we will show how these cases point to a deeper insight about the contexts in which we typically invoke this type of reasoning and some significant harmful consequences of doing so. (shrink)

Dual-process theories hold that there are two distinct processing modes available for many cognitive tasks: one that is fast, automatic and non-conscious, and another that is slow, controlled and conscious. Typically, cognitive biases are attributed to type 1 processes, which are held to be heuristic or associative, and logical responses to type 2 processes, which are characterised as rule-based or analytical. Dual-system theories go further and assign these two types of process to two separate reasoning systems, System 1 and System (...) 2 – a view sometimes described as ‘the two minds hypothesis’. It is often claimed that System 2 is uniquely human and the source of our capacity for abstract and hypothetical thinking. This study is an introduction to dual-process and dual-system theories. It looks at some precursors, surveys key work in the fields of learning, reasoning, social cognition and decision making, and identifies some recent trends and philosophical applications. (shrink)

We examine the role of working memory's central executive in the mental model explanation of propositional reasoning by using two working memory measures: the classical “reading span” test by Daneman and Carpenter (1980) and a new measure. This new “reasoning span” measure requires individuals to solve very simple anaphora problems, and store and remember the word solution in a growing series of inferential problems. We present one experiment in which we check the involvement of the central executive in conditional and (...) disjunctive inference tasks and compare predictions of the new reasoning span test with those of the classical reading span test. The results of the experiment confirm that reasoning responses, which according to mental model theory require high cognitive work, are predicted by working memory measures. Results also show that some reasoning responses are probably obtained by means of superficial biases or strategies that do not load working memory. The reasoning span test, which involves the central executive to a greater degree, predicts reasoning performance better than the reading span test. The significance and possibilities of the new measure in studying reasoning are discussed. (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)

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)

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)

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)

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)

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)

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)

Girotto and Legrenzi's 1993 facilitation effect for their SARS version of Wason s THOG problem a disjunctive reasoning task was examined. The effect was not replicated when the standard THOG problem instructions were used in Experiments 1 and 2. However, in Experiment 3 when Girotto and Legrenzi's precise instructions were used, facilitation was observed. Experiment 4 further investigated the role of the type of instructions in the observed facilitation. The results suggest that such facilitation may result from attentional factors rather (...) than the use of a combinatorial analysis in the problem. (shrink)

In this chapter, we outline the range of argument forms involving causation that can be found in everyday discourse. We also survey empirical work concerned with the generation and evaluation of such arguments. This survey makes clear that there is presently no unified body of research concerned with causal argument. We highlight the benefits of a unified treatment both for those interested in causal cognition and those interested in argumentation, and identify the key challenges that must be met for a (...) full understanding of causal argumentation. (shrink)

Political candidates often believe they must focus their campaign efforts on a small number of swing voters open for ideological change. Based on the wisdom of opinion polls, this might seem like a good idea. But do most voters really hold their political attitudes so firmly that they are unreceptive to persuasion? We tested this premise during the most recent general election in Sweden, in which a left- and a right-wing coalition were locked in a close race. We asked our (...) participants to state their voter intention, and presented them with a political survey of wedge issues between the two coalitions. Using a sleight-of-hand we then altered their replies to place them in the opposite political camp, and invited them to reason about their attitudes on the manipulated issues. Finally, we summarized their survey score, and asked for their voter intention again. The results showed that no more than 22% of the manipulated replies were detected, and that a full 92% of the participants accepted and endorsed our altered political survey score. Furthermore, the final voter intention question indicated that as many as 48% (69.2%) were willing to consider a left-right coalition shift. This can be contrasted with the established polls tracking the Swedish election, which registered maximally 10% voters open for a swing. Our results indicate that political attitudes and partisan divisions can be far more flexible than what is assumed by the polls, and that people can reason about the factual issues of the campaign with considerable openness to change. (shrink)

Analogy making from examples is a central task in intelligent system behavior. A lot of real world problems involve analogy making and generalization. Research investigates these questions by building computer models of human thinking concepts. These concepts can be divided into high level approaches as used in cognitive science and low level models as used in neural networks. Applications range over the spectrum of recognition, categorization and analogy reasoning. A major part of legal reasoning could be formally interpreted as an (...) analogy making process. Because it is not the same as reasoning in mathematics or the physical sciences, it is necessary to use a method, which incorporates first the ability to specify likelihood and second the opportunity of including known court decisions. We use for modelling the analogy making process in legal reasoning neural networks and fuzzy systems. In the first part of the paper a neural network is described to identify precedents of immaterial damages. The second application presents a fuzzy system for determining the required waiting period after traffic accidents. Both examples demonstrate how to model reasoning in legal applications analogous to recent decisions: first, by learning a system with court decisions, and second, by analyzing, modelling and testing the decision making with a fuzzy system. (shrink)

The justificatory force of empirical reasoning always depends upon the existence of some synthetic, a priori justification. The reasoner must begin with justified, substantive constraints on both the prior probability of the conclusion and certain conditional probabilities; otherwise, all possible degrees of belief in the conclusion are left open given the premises. Such constraints cannot in general be empirically justified, on pain of infinite regress. Nor does subjective Bayesianism offer a way out for the empiricist. Despite often-cited convergence theorems, subjective (...) Bayesians cannot hold that any empirical hypothesis is ever objectively justified in the relevant sense. Rationalism is thus the only alternative to an implausible skepticism. (shrink)

This paper presents a new algorithm to find an appropriate similarityunder which we apply legal rules analogically. Since there may exist a lotof similarities between the premises of rule and a case in inquiry, we haveto select an appropriate similarity that is relevant to both thelegal rule and a top goal of our legal reasoning. For this purpose, a newcriterion to distinguish the appropriate similarities from the others isproposed and tested. The criterion is based on Goal-DependentAbstraction (GDA) to select a (...) similarity such that an abstraction basedon the similarity never loses the necessary information to prove the ground (purpose of legislation) of the legal rule. In order to cope withour huge space of similarities, our GDA algorithm uses some constraintsto prune useless similarities. (shrink)

Counterfactual reasoning has always played a role in human life. We ask questions like, “Could it have been different?”, “Under which conditions might/would it have been different?”, “What would have happened if…?” If we don’t find an answer, i.e. what we accept as an answer, we may start reasoning. Reasoning means introducing still new information/assumptions, new questions, new answers to new questions etc. From a formal point of view, it may be compared with stepwise moving towards a destination in a (...) path-system, in which you never fully have an overview. In this way, reasoning is an activity, with its own rationale, which will be studied from the agent’s own perspective. Questions include: What are the conditions where asking that specific question, or introducing this information/assumption, etc. will count as a reasonable step or progress towards the answer of the initial question? What makes this step more reasonable than another? (shrink)

As an introduction to our work, we emphasize the parallel interpretation of abstract tools and the concepts of undetermined and vague information. Imprecision, uncertainty and their relationships are inspected. Suitable interpretations of the fuzzy sets theory are applied to legal phenomena in an attempt to clearly circumscribe the possible applications of the theory. The fundamental notion of reference sets is examined in detail, hence highlighting their importance. A systematic and combinatorial classification of the relevant subsets of the legal field is (...) supplied for practical application. Although the use of the fuzzy sets theory is sometimes suggested as a palliative measure (no competition exists), it can also be complementary (serve as a building block to improve modelisation). An Appendix gives a brief recall of the key-concepts of the axiomatic theory of fuzziness and its developments: fuzzy sets, fuzzy logic, fuzzy control and theory of possibility. (shrink)

David Bloor’s thought experiment is taken into consideration to suggest that the rationality of the Other cannot be inferred by way of argument for the reason that it is unavoidably contained as a hidden supposition by any argument engaged in proving it. We are able to understand a different culture only as far as we recognize in it the same kind of rationality that works in our own culture. Another kind of rationality is either impossible, or indiscernible.

What makes the difference between good and bad reasoning? In this paper we defend a novel account of good reasoning—both theoretical and practical—according to which it preserves fittingness or correctness: good reasoning is reasoning which is such as to take you from fitting attitudes to further fitting attitudes, other things equal. This account, we argue, is preferable to two others that feature in the recent literature. The first, which has been made prominent by John Broome, holds that the standards of (...) good reasoning derive from rational requirements. The second holds that these standards derive from reasons. We argue that these accounts face serious difficulties in correctly distinguishing good from bad reasoning, and in explaining what's worthwhile about good reasoning. We then propose our alternative account and argue that it performs better on these counts. In the final section, we develop certain elements of the account in response to some possible objections. (shrink)

In this paper, I argue that ad hominem arguments are not always fallacious. More explicitly, in certain cases of practical reasoning, the circumstances of a person are relevant to whether or not the conclusion should be accepted. This occurs, I suggest, when a person gives advice to others or prescribes certain courses of action but fails to follow her own advice or act in accordance with her own prescriptions. This is not an instance of a fallacious tu quoque provided that (...) such circumstantial ad hominem arguments are construed as rebuttals to appeals (administrative) authority (of expertise), or so I argue. (shrink)

In this important new book Nagel, one of the most distinguished philosophers writing in English today, presents a sustained defence of reason against the attacks of subjectivism. He offers systematic rebuttals of relativistic claims with respect to language, logic, science, and ethics.

Since at least the 1960s, deontic logicians and ethicists have worried about whether there can be normative systems that allow conflicting obligations. Surprisingly, however, little direct attention has been paid to questions about how we may reason with conflicting obligations. In this paper, I present a problem for making sense of reasoning with conflicting obligations and argue that no deontic logic can solve this problem. I then develop an account of reasoning based on the popular idea in ethics that reasons (...) explain obligations and show that it solves this problem. (shrink)

Este artículo muestra la conexión entre heurísticas sociales y deliberación. En lugar de caracterizar las heurísticas según disciplinas o campos, aquí se proyectan sobre nuestros enclaves deliberativos. La autora sostiene que el empleo de heurísticas sociales orienta el flujo de la información y la participación en las distintas fases deliberativas, y es necesario analizarlas para establecer indicadores con los que medir grados de deliberación. Esta hipótesis da lugar a una visión pluralista sobre la función social de las heurísticas entendidas como (...) caja de herramientas con nuevos instrumentos y utilidades sociales. Según dicha perspectiva, habría que integrar este tipo de razonamiento en un plan de acción más amplio que explicara en qué sentido las heurísticas son recursos que producen conocimiento, al tiempo que un tipo de conocimiento ya producido. (shrink)

La lógica borrosa se ha definido como un sistema preciso de razonamiento, deducción y computación en el que los objetos del discurso se encuentran asociados a información que, por lo general, consideramos imprecisa, incompleta, incierta, poco fiable, parcialmente verdadera o parcialmente posible.

This book examines two questions: Do people make use of abstract rules such as logical and statistical rules when making inferences in everyday life? Can such abstract rules be changed by training? Contrary to the spirit of reductionist theories from behaviorism to connectionism, there is ample evidence that people do make use of abstract rules of inference -- including rules of logic, statistics, causal deduction, and cost-benefit analysis. Such rules, moreover, are easily alterable by instruction as it occurs in classrooms (...) and in brief laboratory training sessions. The fact that purely formal training can alter them and that those taught in one content domain can "escape" to a quite different domain for which they are also highly applicable shows that the rules are highly abstract. The major implication for cognitive science is that people are capable of operating with abstract rules even for concrete, mundane tasks; therefore, any realistic model of human inferential capacity must reflect this fact. The major implication for education is that people can be far more broadly influenced by training than is generally supposed. At high levels of formality and abstraction, relatively brief training can alter the nature of problem-solving for an infinite number of content domains. (shrink)

According to a family of views under the label of epistemic conservatism, the fact that one already believes something can make it rational to continue to believe it. A number of philosophers have found conservatism attractive, but traditional views are vulnerable to several powerful criticisms. In this paper, I develop an alternative to standard views by identifying a widespread assumption shared by conservatives and their critics - that rational norms govern states of mind like belief, and showing how rejecting this (...) assumption in favor of a process-oriented approach opens the door to a new, dynamic form of conservatism which preserves its core motivations while avoiding its traditional objections. (shrink)

What is special about legal reasoning? In what way is it distinctive? How does it differ from reasoning in medicine, or engineering, physics, or everyday life? The answers range from the very ambitious to the modest. The ambitious claim that there is a special and distinctive legal logic, or legal ways of reasoning, modes of reasoning which set the law apart from all other disciplines. Opposing them are the modest, who claim that there is nothing special to legal reasoning, that (...) reason is the same in all domains. According to them, only the contents of the law differentiate it from other areas of inquiry, whereas its mode of reasoning is the one common to all domains of inquiry. (shrink)

The paper argues that normative reasons are of two fundamental kinds, practical which are value related, and adaptive, which are not related to any value, but indicate how our beliefs and emotions should adjust to fit how things are in the world. The distinction is applied and defended, in part through an additional distinction between standard and non-standard reasons (for actions, intentions, emotions or belief).

In this paper I deal with epistemological issues that stem from the hypothesis that reasoning is not only a means of transmitting knowledge from premise-beliefs to conclusion-beliefs, but also a primary source of knowledge in its own right. The idea is that one can gain new knowledge on the basis of suppositional reasoning. After making some preliminary distinctions, I argue that there are no good reasons to think that purported examples of knowledge grounded on pure reasoning are just examples of (...) premise-based inferences in disguise. Next, I establish what kinds of true propositions can to a first approximation be known on the basis of pure reasoning. Finally, I argue that beliefs that are competently formed on the basis of suppositional reasoning satisfy both externalist and internalist criteria of justification. (shrink)

In Section 1, we make some preliminary remarks about the concept of epis‐ temic entitlement, understood in terms of ex ante rationality. In Section 2, we argue that a certain epistemological view – one according to which ex ante rationality is solely a func- tion of available reasons – is inadequate. In Sections 3-4 we will esh out an alternative view about ex ante rationality, one according to which forming a certain belief is rational for a subject S only when (...) S knows how to reason in a certain way. In Section 5 we explore some consequences of our view and we describe the main challenge that we must meet in future work. (shrink)

Persuasion is a special aspect of our social and linguistic practices – one where an interlocutor, or an audience, is induced, to perform a certain action or to endorse a certain belief, and these episodes are not due to the force of the better reason. When we come near persuasion, it seems that, in general, we are somehow giving up factual discourse and the principles of logic, since persuading must be understood as almost different from convincing rationally. Sometimes, for example, (...) we can find persuasion a political speech that relies on our feelings, emotions and values, but we can also find a persuasive person a dodger, busy in his own questionable activities that are intentionally performed in order to mislead and manipulate other people. However, I do not want to try to define a general notion of persuasion from the beginning. I would rather start with a conception that already has a place, even if controversial, in the philosophical debate. In particular, the version that I have always found particularly provocative is that provided by Wittgenstein’s On Certainty. This peculiar version of the idea of persuasion, which is often associated with the possibility of overcoming deep disagreements, is quite famous in the literature and often understood as indicating certain intrinsic limits of our reason-giving practices. The following are Wittgenstein’s famous remarks on persuasion: -/- 608. Is it wrong for me to be guided in my actions by the propositions of physics? Am I to say I have no good ground for doing so? Isn’t precisely this what we call a ‘good ground’? -/- 609. Suppose we met people who did not regard that as a telling reason. Now, how do we imagine this? Instead of the physicist, they consult an oracle. (And for that we consider them primitive.) Is it wrong for them to consult an oracle and be guided by it? If we call this “wrong” aren’t we using our language-game as a base from which to combat theirs? -/- 611. Where two principles really do meet which cannot be reconciled with one another, then each man declares the other a fool and heretic. -/- 612. I said I would ‘combat’ the other man, – but wouldn’t I give him reasons? Certainly; but how far do they go? At the end of reasons comes persuasion. (Think what happens when missionaries convert natives.) -/- This paper is not devoted, as far as possible, to focus on interpretative matters about Wittgenstein’s late philosophy. Rather, it aims to investigate whether there are problems and incompatibilities between this particular conception of persuasion and our contemporary understanding of our reason-giving practices and of our belief-revision procedures. The first part of this study will be concerned about assessing this conception of persuasion and trying to shed new light on it (and on its consequences); most of the work here is done by looking at some truisms and normative features of our practices regarding the rational updating of our beliefs. It also addresses the question: Is the resistance to reasons of Wittgenstein’s persuasion capable to avoid the strict dynamics of belief revision? The second section of this study concerns the possibility of limiting the scope of this conception of persuasion, thanks to some of our contemporary ways of understanding rational discursive practices (I will focus especially on Robert Brandom’s game of “giving and asking for reasons”). If our rational practices require at least a certain degree of epistemic responsibility, then how is it possible that one invokes the end of reasons (that would explicitly mean giving up this responsibility)? A third section is the attempt, on this basis, to try to revise our contrasting conception(s) of persuasion (with an eye open on the near doxastic territory). Are there other conceptions of persuasion which are more compatible with our rational practices and do not entail any version of the “end of reasons” that are so compatible with our individual and social epistemic responsibility? (shrink)

We are justified in employing the rule of inference Modus Ponens (or one much like it) as basic in our reasoning. By contrast, we are not justified in employing a rule of inference that permits inferring to some difficult mathematical theorem from the relevant axioms in a single step. Such an inferential step is intuitively “too large” to count as justified. What accounts for this difference? In this paper, I canvass several possible explanations. I argue that the most promising approach (...) is to appeal to features like usefulness or indispensability to important or required cognitive projects. On the resulting view, whether an inferential step counts as large or small depends on the importance of the relevant rule of inference in our thought. (shrink)

Mathematics used to be portrayed as a deductive science. Stemming from Polya , however, is a philosophical movement which broadens the concept of mathematical reasoning to include inductive or quasi-empirical methods. Interest in inductive methods is a welcome turn from foundationalism toward a philosophy grounded in mathematical practice. Regrettably, though, the conception of mathematical reasoning embraced by quasi-empiricists is still too narrow to include the sort of thought-experiment which Mueller describes as traditional mathematical proof and which Lakatos examines in Proofs (...) and refutations . This paper extends the concept of mathematical reasoning along two further dimensions to accommodate thought-experiment.Keywords: Thought-experiment; Informal proof; Mathematical reasoning. (shrink)

This paper analyses the logical structure of the balancing of conflicting normative arguments, and asks whether non-monotonic logic is adequate to represent this type of legal or practical reasoning. Norm conflicts are often regarded as a field of application for non-monotonic logics. This paper argues, however, that the balancing of normative arguments consists of an act of judgement, not a logical inference, and that models of deductive as well as of defeasible reasoning do not give an adequate account of its (...) structure. Moreover, it argues that as far as the argumentation consists in logical inferences, deductive logic suffices for reconstructing the argumentation from the internal point of view of someone making normative judgements. (shrink)

In this study we investigate the influence of reason-relation readings of indicative conditionals and ‘and’/‘but’/‘therefore’ sentences on various cognitive assessments. According to the Frege-Grice tradition, a dissociation is expected. Specifically, differences in the reason-relation reading of these sentences should affect participants’ evaluations of their acceptability but not of their truth value. In two experiments we tested this assumption by introducing a relevance manipulation into the truth-table task as well as in other tasks assessing the participants’ acceptability and probability evaluations. Across (...) the two experiments a strong dissociation was found. The reason-relation reading of all four sentences strongly affected their probability and acceptability evaluations, but hardly affected their respective truth evaluations. Implications of this result for recent work on indicative conditionals are discussed. (shrink)

In this paper I am concerned with the question of whether degrees of belief can figure in reasoning processes that are executed by humans. It is generally accepted that outright beliefs and intentions can be part of reasoning processes, but the role of degrees of belief remains unclear. The literature on subjective Bayesianism, which seems to be the natural place to look for discussions of the role of degrees of belief in reasoning, does not address the question of whether degrees (...) of belief play a role in real agents’ reasoning processes. On the other hand, the philosophical literature on reasoning, which relies much less heavily on idealizing assumptions about reasoners than Bayesianism, is almost exclusively concerned with outright belief. One possible explanation for why no philosopher has yet developed an account of reasoning with degrees of belief is that reasoning with degrees of belief is not possible for humans. In this paper, I will consider three arguments for this claim. I will show why these arguments are flawed, and conclude that, at least as far as these arguments are concerned, it seems like there is no good reason why the topic of reasoning with degrees of belief has received so little attention. (shrink)

Does cognition sometimes literally extend into the extra-organismic environment (Clark, 2003), or is it always “merely” environmentally embedded (Rupert, 2004)? Underlying this current border dispute is the question about how to individuate cognitive processes on principled grounds. Based on recent evidence about the active role of representation selection and construction in learning how to reason (Stenning, 2002), I raise the question: what makes two distinct, modality-specific pen-and-paper manipulations of external representations – diagrams versus sentences – cognitive processes of the same (...) kind, e.g. episodes of syllogistic reasoning? In response, I defend a “division of labor” hypothesis, according to which external representations are dependent on perceptually grounded neural representations and mechanisms to guide our behavior; these internal mechanisms, however, are dependent on external representations to have their syllogistic content fixed. Only their joint contributions qualify the extended computational process as an episode of syllogistic reasoning in good standing. (shrink)

Different people reason differently, which means that sometimes they reach different conclusions from the same evidence. We maintain that this is not only natural, but rational. In this essay we explore the epistemology of that state of affairs. First we will canvass arguments for and against the claim that rational methods of reasoning must always reach the same conclusions from the same evidence. Then we will consider whether the acknowledgment that people have divergent rational reasoning methods should undermine one’s confidence (...) in one’s own reasoning. Finally we will explore how agents who employ distinct yet equally rational methods of reasoning should respond to interactions with the products of each others’ reasoning. We find that the epistemology of multiple reasoning methods has been misunderstood by a number of authors writing on epistemic permissiveness and peer disagreement. (shrink)