Peter Brössel and Franz Huber in 2015 argued that the Bayesian concept of confirmation had no use. I will argue that it has both the uses they discussed—it can be used for making claims about how worthy of belief various hypotheses are, and it can be used to measure the epistemic value of experiments. Furthermore, it can be useful in explanations. More generally, I will argue that more coarse-grained concepts can be useful, even when we have more fine-grained concepts available.

According to the logical pluralism of Beall and Restall, there are several distinct relations of logical consequence. Some critics argue that logical pluralism suffers from what I call the collapse problem: that despite its intention to articulate a radically pluralistic doctrine about logic, the view unintentionally collapses into logical monism. In this paper, I propose a contextualist resolution of the collapse problem. This clarifies the mechanism responsible for a plurality of logics and handles the motivating data better than the original (...) view. It is a major improvement that should be embraced by all logical pluralists. (shrink)

Jonathan Dancy challenges moral generalists to come up with a picture of moral thought and judgment which requires a provision of principles that cover the ground. The aim of this paper is to provide a response to Dancy's challenge. I argue that reasonable moral thought requires us to explain ourselves when we have reason to doubt our moral judgment about some particular case, that any such explanation commits us to a general moral principle over some domain of discussion and that (...) this principle expands to cover more and more ground as we consider more and more cases. (shrink)

Ordinary common knowledge is formally expressed by strong probabilistic common belief. How strong exactly? The question can be answered by drawing from the similar equivalence, recently explored, between plain and probabilistic individual beliefs. I argue that such a move entails that common knowledge displays a double fragility: as a description of a collective state and as a phenomenon, because it can respectively disappear as group size increases, or more worryingly as the epistemic context changes. I argue that despite this latter (...) fragility, the effects of common knowledge on action are robust. Unfortunately, this in turn leads to a third fragility, that of the concept of common knowledge, which threatens to collapse on probabilistic common belief. This also reveals a disanalogy between the individual and the collective cases. I finally pinpoint the subtle difference entailed by the two concepts, expressed in terms of the attitude towards contrary evidence or of the agents’ awareness. As a result, common knowledge can be defended as a concept, which refers to a fragile yet distinct collective attitude. (shrink)

Argumentation is a dialogical attempt to bring about a desired change in the beliefs of another agent – that is, to trigger a specific belief revision process in the mind of such agent. However, so far formal models of belief revision widely neglected any systematic comparison with argumentation theories, to the point that even the simplest argumentation structures cannot be captured within such models. In this essay, we endeavour to bring together argumentation and belief revision in the same formal framework, (...) and to highlight the important role played by Toulmin’s layout of argument in fostering such integration. (shrink)

This paper critically evaluates the celebrated paper of Hanks and McDermott on temporal projection, non-monotonic reasoning, and the frame problem. First I argue against their intuitions, and a fortiori, against their proposed solution. Next, I suggest how the solution they desire could be obtained, were they willing to represent the problem a bit differently.

In this paper, I propose that one can have reason to choose a few tickets in a very large lottery and arbitrarily believe of them that they will lose. Such a view fits nicely within portions of Lehrer's theory of rational acceptance. Nonetheless, the reasonability of believing a lottery ticket will lose should not be taken to constitute the kind of justification required in an analysis of knowledge. Moreover, one should not accept what one takes to have a low chance (...) of being true. Accordingly, one should take care not to believe of too many tickets that they are to lose. Finally, while arbitrariness is no absolute barrier to epistemic reasonability, one may not be able to believe that one's lottery ticket will lose if one cannot regard oneself as knowing it will lose. (shrink)

This paper argues that the prominent accounts of logical knowledge have the consequence that they conflict with ordinary reasoning. On these accounts knowing a logical principle, for instance, is having a disposition to infer according to it. These accounts in particular conflict with so-called ‘reasoned change in view’, where someone does not infer according to a logical principle but revise their views instead. The paper also outlines a propositional account of logical knowledge which does not conflict with ordinary reasoning.

Je suis trés reconnaissant à Michel Seymour d'avoir soumis mon livre à un examen détaillé, pénétrant, et charitable et d'avoir, par ses objections, mis le doigt sur un certain nombre de présupposés des thèses défendues dans ce livre, qu'il a souvent articulés bien mieux que je n'ai été capable de le faire. Le principal de ces présupposés est mon rejet implicite de la thése quinienne de l'indétermination de la traduction, qui m'engage, selon Seymour, à défendre une conception conservatrice de la (...) logique et à insister sur une détermination de son domaine qui lui paraît injustifiée. Seymour soutient au contraire qu'il faut admettre cette thése, qui «commande une tout autre perspective» que la mienne. Je voudrais à la fois résister à la prémisse et à la conclusion de cette inférence. (shrink)

We distinguish the set of explicit beliefs of a reasoner, his "belief base", from the beliefs that are merely implicit. Syntax-based belief change governed by the structure of the belief base and the ranking ("prioritization") of its elements is reconstructed with the help of an epistemic entrenchment relation in the style of Gärdenfors and Makinson. Though priorities are essentially different from entrenchments, distinguished relations of epistemic entrenchment may be obtained from prioritized belief bases by a number of different constructions. An (...) approximate reconstruction of syntax-based belief change is possible, which can be strengthened to a strict identity in some important special cases. A competitive interpretation and a minimal change interpretation of the basic idea of entrenchment are discussed. It is argued that entrenchment essentially involves multiple belief changes, i.e., changes by sets of sentences. (shrink)

This volume presents mathematical game theory as an interface between logic and philosophy.

The underconsideration argument against inference to the best explanation and scientific realism holds that scientists are not warranted in inferring that the best theory is true, because scientists only ever conceive of a small handful of theories at one time, and as a result, they may not have considered a true theory. However, antirealists have not developed a detailed alternative account of why explanatory inference nevertheless appears so central to scientific practice. In this paper, I provide new defences against some (...) recent objections to the underconsideration argument, while also developing an account of explanatory inference that both survives these criticisms and does not entail realism. (shrink)

In this paper, I examine an account of instrumental reasoning recently put forth by John Broome. His key suggestion is that anyone who engages in reasoning about his intentions also believes that he will do what he intends to do and that combined with a belief about necessary means this creates rational pressure towards believing that one will take the necessary means. I argue that Broome’s model has three significant problems; his key premise is false—the sincere expression of an intention (...) does not entail the belief that one will successfully execute that intention; his account yields a model of instrumental reasoning that is uncomfortably reflective; he seems unable to explain the rational pressure towards taking necessary means that arises directly from having an end and an instrumental belief. All three problems, I argue, are a consequence of Broome’s inadequate position on what it is to intend to do something. (shrink)

Human cognition requires coping with a complex and uncertain world. This suggests that dealing with uncertainty may be the central challenge for human reasoning. In Bayesian Rationality we argue that probability theory, the calculus of uncertainty, is the right framework in which to understand everyday reasoning. We also argue that probability theory explains behavior, even on experimental tasks that have been designed to probe people's logical reasoning abilities. Most commentators agree on the centrality of uncertainty; some suggest that there is (...) a residual role for logic in understanding reasoning; and others put forward alternative formalisms for uncertain reasoning, or raise specific technical, methodological, or empirical challenges. In responding to these points, we aim to clarify the scope and limits of probability and logic in cognitive science; explore the meaning of the explanation of cognition; and re-evaluate the empirical case for Bayesian rationality. (shrink)

We present a modal logic called (logic of intention and attempt) in which we can reason about intention dynamics and intentional action execution. By exploiting the expressive power of , we provide a formal analysis of the relation between intention and action and highlight the pivotal role of attempt in action execution. Besides, we deal with the problems of instrumental reasoning and intention persistence.

We prove that four theses commonly associated with coherentism are incompatible with the representation of a belief state as a logically closed set of sentences. The result is applied to the conventional coherence interpretation of the AGM theory of belief revision, which appears not to be tenable. Our argument also counts against the coherentistic acceptability of a certain form of propositional holism. We argue that the problems arise as an effect of ignoring the distinction between derived and non-derived beliefs, and (...) we suggest that the kind of coherence relevant to epistemic justification is the coherence of non-derived beliefs. (shrink)

Practical reasoning aims at deciding what actions to perform in light of the goals a rational agent possesses. This has been a topic of interest in both philosophy and artificial intelligence, but these two disciplines have produced very different models of practical reasoning. The purpose of this paper is to examine each model in light of the other and produce a unified model adequate for the purposes of both disciplines and superior to the standard models employed by either.The philosophical (decision-theoretic) (...) model directs activity by evaluating acts one at a time in terms of their expected utilities. It is argued that, except in certain special cases, this constitutes an inadequate theory of practical reasoning leading to intuitively incorrect action prescriptions. Acts must be viewed as parts of plans, and plans evaluated as coherent units rather than piecemenal in terms of the acts comprising them. Rationality dictates choosing acts by first choosing the plans prescribing them. Plans, in turn, are compared by looking at their expected values. However, because plans can be embedded in one another, we cannot select plans just by maximizing expected values. Instead, we must employ a more complex criterion here named coextendability. (shrink)

The view to be defended in this paper is intended to be a novel and compelling model of instrumental practical reasoning, reasoning aimed at determining how to act in order to achieve a given end in a certain set of circumstances. On standard views of instrumental reasoning, the end in question is the object of a particular desire that the agent has, a desire which, when combined with the agent’s beliefs about what means are available to him or her in (...) order to satisfy that desire, can cause the formation of an independent desire or intention to engage in the relevant means. One of the main goals in what follows is to show that such views provide an inadequate understanding of instrumental practical reasoning when it comes to the practical lives of agents. We shall proceed as follows. After some background assumptions are outlined in the next section, two important and largely neglected challenges will be raised to any view of instrumental practical reasoning (hereafter IP reasoning) which only countenances the role of end-directed desires and means-end beliefs in the mental economy of agents. In my view, neither of these challenges can be met, or at least not in any straightforward way. Hence the remainder of the paper is devoted to articulating and defending a new approach to understanding the structure of instrumental practical reasoning. The heart of this positive view will involve the addition of a normative belief concerning the desirability of the agent’s end. (shrink)

It is a platitude that belief is subject to a standard of correctness: a belief is correct if and only if it is true. But not all standards of correctness are authoritative or binding. Some standards of correctness may be arbitrary, unjustified or outrightly wrong. Given this, one challenge to proponents of the truth norm of belief, is to answer what Korsgaard (1996) calls ‘the normative question’. Is the truth norm of belief authoritative or binding regarding what one ought to (...) or may believe? If so, what grounds its authority? The aim of this paper is to offer a novel answer to the grounding challenge on a reason-based normative framework. I develop and defend a practice-based account of the truth norm, according to which, the authority of the truth norm of belief is grounded in what I call the T-practice, a justified social practice that functions to facilitate knowledge production, maintenance, and social cooperation. (shrink)

In this paper, I respond to what I have called an epistemological objection to a dialetheist approach to the doctrine of the Incarnation, of which one example is Beall’s contradictory Christ. I discuss Anderson’s book Paradox in Christian theology, in which the author claims to account for the rationality of the doctrine of the Incarnation as a merely apparently contradictory doctrine, and I present my model, based on Anderson’s model, according to which the doctrine has the possibility to be rational (...) by understanding it as genuinely contradictory. I show that this model fits perfectly well with the criteria that, according to Anderson, any model for the rationality of a paradoxical doctrine should meet. Beall does not address the problem of the rationality of the doctrine in his works about the contradictory Christ, and he asserts that he is not interested in it. However, I think that if he wants to make his theory more robust, less suspicious, and more convincing for theologians, philosophers, and ordinary people, he should consider this problem. (shrink)

In this paper, I take issue with a core commitment of logical conventionalism: that we impose a logic on ourselves by adopting general linguistic conventions governing our use of logical terms, thereby determining the meanings of the logical constants and which of our inferences are valid. Drawing on Kripke’s ‘adoption problem’, I argue that general logical principles cannot be adopted, either explicitly or implicitly. I go on to argue that the meanings of our logical terms, and the validity of our (...) inferences, cannot depend on our adoption of logico-linguistic conventions. (shrink)

Common-sense philosophers typically maintain that common-sense propositions have a certain kind of epistemic privilege that allows them to evade the threats of skepticism or radical revisionism. Butwhydo they have this special privilege? In response to this question, the “Common-Sense Tradition” contains many different strands of arguments. In this paper, I will develop a strategy that combines two of these strands of arguments. First, the “Dynamic Argument” (or the “starting-point argument”), inspired by Thomas Reid and Charles S. Peirce (but which will (...) be strengthened with the help of Gilbert Harman’s epistemology of belief revision). Second, G.E. Moore’s “greater certainty argument” (interpreted along the lines of Soames’ and Pollock’s construal). This combined strategy, I will argue, is the strong core of Common-Sense Philosophy, and relies on extremely modest and widely held assumptions. (shrink)

The background of this paper (section 1) consists in a new account to foundation‐theoretic epistemology characterized by two features: (i) All beliefs are to be justified by deductive, inductive or abductive inferences from a minimalistic class of unproblematic (introspective or analytic) basic beliefs. (ii) Higher‐order justifications for these inferences are given by means of the novel method of optimality justifications. Optimality justifications are a new tool for epistemology (section 2). An optimality justification does not attempt todemonstratethat a cognitive method is (...) reliable (which is impossible), but pursues the more modest goal of demonstrating that the method isoptimalamong all accessible alternative methods for the given epistemic goal. The reasoning from the established optimality of a method to the acceptability of a particular belief generated by the method is accomplished by so‐called optimality principles. In sections 3–5, the method of optimality justifications is carried out in detail for three fundamental problems: justifying induction, logic, and theory‐generating abduction. (shrink)

It is argued that higher-order awareness is central to one type of everyday rationality. The author starts by specifying the target notion of rationality, contrasting it with other useful notions in the neighbourhood. It is then shown that the target notion relies on first-person awareness of the unfolding of cognition. This is used to explain the kernel of truth in epistemic conservatism, the structure of defeasibility, and the root motive behind the widely accepted distinction between rational inference and trivial entailment.

I argue that there is a prima facie tension between solutions to the problem of fake news and solutions to the problem presented by various cognitive biases that dispose us to dismiss evidence against our prior beliefs (what might seem to be the driving force behind echo chambers). We can guard against fake news by strengthening belief. But we can exit echo chambers by becoming more sensitive to counterevidence, which seems to require weakening our beliefs. I resolve the tension by (...) arguing against an injunction to weaken belief in the required ways. In particular, there is no injunction to be open-minded in all circumstances toward various counterarguments, even those whose premises seem compelling and in which we can’t expose a flaw. On the contrary, there are circumstances in which you should, in the relevant sense, be closed-minded toward such counterarguments. (shrink)

In ‘Reasoning and Regress’ I argued that inferring a conclusion from a set of propositions may simply consist in taking it that the conclusion follows from these propositions—thereby defusing familiar regress arguments. Sinan Dogramaci challenges the generality of this view, on the grounds that sometimes you may draw conclusions from no premisses that you believe. I respond by clarifying a distinction between the premisses of an argument from the reasons your conclusion is based upon. While suppositional reasoning may involve no (...) premisses in the former sense, it does not follow that it does not involve concluding something on the basis of reasons. This allows the view defended in ‘Reasoning and Regress’ to extend to suppositional reasoning. (shrink)

I develop a non-representationalist account of mathematical thought, on which the point of mathematical theorizing is to provide us with the conceptual capacity to structure and articulate information about the physical world in an epistemically useful way. On my view, accepting a mathematical theory is not a matter of having a belief about some subject matter; it is rather a matter of structuring logical space, in a sense to be made precise. This provides an elegant account of the cognitive utility (...) of mathematics. Further, it makes explicit how the brand of non-representationalism I develop is compatible with there being substantive rationality constraints on our mathematical theorizing. (shrink)

Many have the intuition that the right response to the Lottery Paradox is to deny that one can justifiably believe of even a single lottery ticket that it will lose. The paper shows that from any theory of justification that solves the paradox in accordance with this intuition, a theory not of that kind can be derived that also solves the paradox but is more conducive to our epistemic goal than the former. It is argued that currently there is no (...) valid reason not to give preference to the derived accounts over the accounts from which they come. (shrink)

The principle of belief persistence, or conservativity principle, states that ’\Nhen changing beliefs in response to new evidence, you should continue to believe as many of the old beliefs as possible' (Harman, 1986, p. 46). In particular, this means that if an individual gets new information, she has to accommodate it in her new belief set (the set of propositions she believes), and, if the new information is not inconsistent with the old belief set, then (1) the individual has to (...) maintain all the beliefs she previously had and (2) the change should be minimal in the sense that every proposition in the new belief set must be deducible from the union of the old belief set and the new information (see, e.g., Gardenfors, 1988; Stalnaker, 1984). We focus on this minimal notion of belief persistence and characterize it both semantically and syntactically. A ’possible world' semantic formalization of the principle easily comes to mind. The set of all the propositions that the individual believes corresponds to the set of states of the world that she considers possible and is a subset of the set of states that are not ruled out by the individual's information (or knowledge). It is required that, if the individual considers a state possible and her new information does not exclude this state, then she continue to consider it possible. Furthermore, if the individual regards a particular state as impossible, then she should continue to regard it as impossible unless her new information excludes all the states that she previously regarded as possible. This is closely related to the.. (shrink)

El objetivo de este trabajo consiste en presentar una forma de conservadurismo epistémico que sea integral, y que sostiene lo siguiente: a partir de que S cree que p, como respuesta exitosa a su entorno, p adquiere un estatus epistémico favorable por el cual es racional que la creencia se mantenga hasta que aparezcan evidencias superadoras que sean alternativas e incompatibles con p. Además, se indagará en desarrollos posibles que puedan hacer de la versión integral un principio prometedor y a (...) la vez plausible, para concluir que otorga racionalidad a nuestros compromisos doxásticos mediante la constante mejora de las habilidades cognitivas. (shrink)

It's often thought that when we reason to new judgments in inference, we aim at believing the truth, and that this aim of ours can explain important psychological and normative features of belief. I reject this picture: the structure of aimed activity shows that inference is not guided by a truth‐aim. This finding clears the way for a positive understanding of how epistemic goods feature in our doxastic lives. We can indeed make sense of many of our inquisitive and deliberative (...) activities as undertaken in pursuit of such goods; but the evidence‐guided inferences in which those activities culminate will require a different theoretical approach. (shrink)

In this paper, I examine Gilbert Ryle’s claim that ordinary competence with logical principles or rules is a kind of knowing how, where such knowledge is understood as a skill, a multi-track disposition. Ryle argues that his account of ordinary logical competence helps avoid Lewis Carroll’s famous regress argument (Carroll 1895), which suggests that elementary deductive reasoning might be impossible. Indeed, Carroll’s regress is the central motivation for Ryle’s account. I argue that this account is inadequate on two counts: it (...) cannot serve to articulate the way ordinary reasoners might exercise their knowledge in reasoning and it does not do much to help us avoid Carroll’s regress. I sketch an alternative view, still Rylean in spirit, that fares better on both counts. (shrink)

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

Inferences are familiar movements of thought, but despite important recent work on the topic, we do not yet have a fully satisfying theory of inference. Here I provide a functionalist theory of inference. I argue that the functionalist framework allows us the flexibility to meet various demands on a theory of inference that have been proposed (such as that it must explain inferential Moorean phenomena and epistemological ‘taking’). While also allowing us to compare, contrast, adapt, and combine features of extant (...) theories of inference into one unified theory. In fleshing out the inference role, I also criticize the common assumption that inference requires rule-following. (shrink)

Cogency is the central normative concept of informal logic. But it is a loose evaluative concept and I argue that a generic notion covering all of the qualities of a well-reasoned argument is the most plausible conception. It is best captured by the standard RSA criterion: in a good argument acceptable (A) and relevant (R) premises provide sufficient (S) grounds for the conclusion. Logical qualities in a broad sense are affected by the epistemic qualities of the premises and “consequence” in (...) a broad sense exhibits an interplay of form and content. There are four proposals for the premise—conclusion relation: (i) no strictly logical connection (“non-logical” consequence); (ii) one type of connection only (deductivism); (iii) a few types of connection (deduction, induction, perhaps conduction and analogical reasoning); (iv) many types of connection (argumentation schemes). Deductivism is a serious option but in its strong version, as the discussion about petitio shows, it fails to establish that arguments which are not cogent are thereby invalid. And weak deductivism, very attractive from the pedagogical point of view, has some deficiencies (implausible hidden premises; preservation of truth, not probability). I argue that the idea of a counterexample, when we regard certain components of the argument as fixed and others as variable, is the best approach to the analysis of the illative core of every-day arguments (the approach of David Hitchcock on material consequence). (shrink)

Evolutionary psychology tends to be associated with a massively modular cognitive architecture. On this framework of human cognition, an assembly of specialized information processors called modules developed under selection pressures encountered throughout the phylogenic history of hominids. The coordinated activity of domain-specific modules carries out all the processes of belief fixation, abstract reasoning, and other facets of central cognition. Against the massive modularity thesis, I defend an account of systemic functional adaptedness, according to which non-modular systems emerged because of adaptive (...) problems imposed by the intrinsic physiology of the evolving human brain. The proposed reformulation of evolutionary theorizing draws from neural network models and Cummins’ (1975) account of systemic functions to identify selection pressures that gave rise to non-modular, domain-general mechanisms in cognitive architecture. (shrink)

According to a popular closure principle for epistemic justification, if one is justified in believing each of the premises in set Φ and one comes to believe that ψ on the basis of competently deducing ψ from Φ—while retaining justified beliefs in the premises—then one is justified in believing that ψ. This principle is prima facie compelling; it seems to capture the sense in which competent deduction is an epistemically secure means to extend belief. However, even the single-premise version of (...) this closure principle is in conflict with certain seemingly good inferences involving the epistemic possibility modal ♢. According to other compelling principles concerning competent deduction and epistemic justification, one can competently infer ¬♢φ from ¬φ in deliberation even though there are cases in which one can justifiably believe ¬φ but would be unjustified in believing ¬♢φ. Thus, as we argue, philosophers must choose between unrestricted closure for justification and the validity of these other principles. (shrink)