This paper defends an account of full belief, including an account of its relationship to credence. Along the way, I address several familiar and difficult questions about belief. Does fully believing a proposition require having maximal confidence in it? Are rational beliefs closed under entailment, or does the preface paradox show that rational agents can believe inconsistent propositions? Does whether you believe a proposition depend partly on your practical interests? My account of belief resolves the tension (...) between conflicting answers to these questions that have been defended in the literature. In addition, my account complements fruitful probabilistic theories of assertion and knowledge. (shrink)

As van Fraassen pointed out in his opening remarks, Henry Kyburg's lottery paradox has long been known to raise difficulties in attempts to represent full belief as a probability greater than or equal to p, where p is some number less than 1. Recently, Patrick Maher has pointed out that to identify full belief with probability equal to 1 presents similar difficulties. In his paper, van Fraassen investigates ways of representing full belief by personal (...) probability which avoid the difficulties raised by Maher's measure-theoretic version of the lottery paradox. Van Fraassen's more subtle representation dissolves the simple identification of full belief with maximal personal probability. His investigation exploits the richer resources for representing opinion provided by taking conditional, rather than unconditional, personal probability as fundamental. It has interesting implications for equivalent alternative approaches based on non-Archimedean probability, as well as for equivalent approaches in which assumption contexts representing full belief relative to suppositions are taken as fundamental. (shrink)

A new formal model of belief dynamics is proposed, in which the epistemic agent has both probabilistic beliefs and full beliefs. The agent has full belief in a proposition if and only if she considers the probability that it is false to be so close to zero that she chooses to disregard that probability. She treats such a proposition as having the probability 1, but, importantly, she is still willing and able to revise that probability assignment (...) if she receives information that gives her sufficient reasons to do so. Such a proposition is undoubted, but not undoubtable. In the formal model it is assigned a probability 1 − δ, where δ is an infinitesimal number. The proposed model employs probabilistic belief states that contain several underlying probability functions representing alternative probabilistic states of the world. Furthermore, a distinction is made between update and revision, in the same way as in the literature on belief change. The formal properties of the model are investigated, including properties relevant for learning from experience. The set of propositions whose probabilities are infinitesimally close to 1 forms a belief set. Operations that change the probabilistic belief state give rise to changes in this belief set, which have much in common with traditional operations of belief change. (shrink)

Stalnaker, 169–199 2006) introduced a combined epistemic-doxastic logic that can formally express a strong concept of belief, a concept of belief as ‘subjective certainty’. In this paper, we provide a topological semantics for belief, in particular, for Stalnaker’s notion of belief defined as ‘epistemic possibility of knowledge’, in terms of the closure of the interior operator on extremally disconnected spaces. This semantics extends the standard topological interpretation of knowledge with a new topological semantics for belief. (...) We prove that the belief logic KD45 is sound and complete with respect to the class of extremally disconnected spaces and we compare our approach to a different topological setting in which belief is interpreted in terms of the derived set operator. We also study belief revision as well as belief dynamics by providing a topological semantics for conditional belief and belief update modalities, respectively. Our setting based on extremally disconnected spaces, however, encounters problems when extended with dynamic updates. We then propose a solution consisting in interpreting belief in a similar way based on hereditarily extremally disconnected spaces, and axiomatize the belief logic of hereditarily extremally disconnected spaces. Finally, we provide a complete axiomatization of the logic of conditional belief and knowledge, as well as a complete axiomatization of the corresponding dynamic logic. (shrink)

Belief is typically understood to be the success‐neutral counterpart of knowledge. But there is no success‐neutral counterpart of knowledge.

Arguments for probabilism aim to undergird/motivate a synchronic probabilistic coherence norm for partial beliefs. Standard arguments for probabilism are all of the form: An agent S has a non-probabilistic partial belief function b iff (⇐⇒) S has some “bad” property B (in virtue of the fact that their p.b.f. b has a certain kind of formal property F). These arguments rest on Theorems (⇒) and Converse Theorems (⇐): b is non-Pr ⇐⇒ b has formal property F.

Let L be a language containing the modal operator B - for full belief. An information model is a set E of stable L-theories. A sentence is valid if it is accepted in all theories of every model.

"To some people, life is very simple . . . no shadings and grays, all blacks and whites. . . . Now, others of us find that good, bad, right, wrong, are many-sided, complex things. We try to see every side; but the more we see, the less sure we are." —Sir John Talbot, The Wolf Man (Universal Pictures, 1941).

"To some people, life is very simple . . . no shadings and grays, all blacks and whites. . . . Now, others of us find that good, bad, right, wrong, are many-sided, complex things. We try to see every side; but the more we see, the less sure we are.".

Belief is considered a kind of performance, which attains one level of success if it is true (or accurate), a second level if competent (or adroit), and a third if true because competent (or apt). Knowledge on one level (the animal level) is apt belief. The epistemic normativity constitutive of such knowledge is thus a kind of performance normativity. A problem is posed for this account by the fact that suspension of belief seems to fall under the (...) same sort of epistemic normativity as does belief itself, yet to suspend is of course precisely not to perform, certainly not with the aim of truth. The paper takes up this problem, and proposes a solution that distinguishes levels of performance norrmativity, including a first order where execution competence is in play, and a second order where the performer must assess the risks attendant on issuing a first-order performance. This imports a level of reflective knowledge that ascends above the animal level. (shrink)

Belief is considered a kind of performance, which attains one level of success if it is true, a second level if competent, and a third if true because competent. Knowledge on one level is apt belief. The epistemic normativity constitutive of such knowledge is thus a kind of performance normativity. A problem is posed for this account by the fact that suspension of belief seems to fall under the same sort of epistemic normativity as does belief (...) itself, yet to suspend is of course precisely not to perform, certainly not with the aim of truth. The paper takes up this problem, and proposes a solution that distinguishes levels of performance normativity, including a first order where execution competence is in play, and a second order where the performer must assess the risks attendant on issuing a first-order performance. This imports a level of reflective knowledge that ascends above the animal level. (shrink)

[ES] La creencia es considerada como una especie de expresión, que alcanza un nivel de éxito si es verdadera, un segundo nivel si es competente, y un tercero si es verdadera por ser competente. El conocimiento a un nivel es una creencia apta. La normatividad epistémica que constituye tal conocimiento es, de esta manera, una especie de normatividad de la expresión. Un problema surge para esta explicación del hecho de que la suspensión de la creencia parece caer bajo la misma (...) especie de normatividad epistémica que la creencia misma; aunque suspender es, sin embargo, precisamente no actuar, en todo caso no teniendo como objetivo la verdad. El presente trabajo examina este problema, y propone una solución que distingue varios niveles de normatividad de expresión, incluyendo un primer orden donde la competencia de expresión está en juego, y un segundo orden en que el ejecutante tiene que evaluar el riesgo concomitante con la realización de una expresión de primer orden. Esto introduce un nivel de conocimiento reflexivo que se eleva encima del nivel animal. [EN] Belief is considered a kind of performance, which attains one level of success if it is true, a second level if competent, and a third if true because competent. Knowledge on one level is apt belief. The epistemic normativity constitutive of such knowledge is thus a kind of performance normativity. A problem is posed for this account by the fact that suspension of belief seems to fall under the same sort of epistemic normativity as does belief itself, yet to suspend is of course precisely not to perform, certainly not with the aim of truth. The paper takes up this problem, and proposes a solution that distinguishes levels of performance normativity, including a first order where execution competence is in play, and a second order where the performer must assess the risks attendant on issuing a first-order performance. This imports a level of reflective knowledge that ascends above the animal level. (shrink)

It is tempting to posit an intimate relationship between belief and assertion. The speech act of assertion seems like a way of transferring the speaker’s belief to his or her audience. If this is right, then you might think that the evidential warrant required for asserting a proposition is just the same as the warrant for believing it. We call this thesis entitlement equality. We argue here that entitlement equality is false, because our everyday notion of belief (...) is unambiguously a weak one. Believing something is true, we argue, is compatible with having relatively little confidence in it. Asserting something requires something closer to complete confidence. Specifically, we argue that believing a proposition merely requires thinking it likely, but that thinking that a proposition is likely does not entitle one to assert it. This conclusion conflict with a standard view that ‘full belief’ is the central commonsense non-factive attitude. (shrink)

Neither full belief nor partial belief is more fundamental, ontologically speaking. A survey of some relevant cognitive psychology supports a dualist ontology instead. Beliefs come in two kinds, categorical and graded, neither more fundamental than the other. In particular, the graded kind is no more fundamental. When we discuss belief in on/off terms, we are not speaking coarsely or informally about states that are ultimately credal.

This book gives a general theory of rational belief. Although it can be read by itself, is a sequel to the author's previous book The Value of Rationality (Oxford, 2017). It takes the general conception of rationality that was defended in that earlier book, and combines it with an account of the varieties of belief, and of what it is for these beliefs to count as "correct", to develop an account of what it is for beliefs to count (...) as rational. According to this account, rationality comes in degrees: the degree to which one's beliefs counts as rational is determined by their distance from a corresponding probability function - where this distance is measured by those beliefs' "expected degree of incorrectness" according to the probability function; the account also involves an explanation of what determines exactly which probability function plays this role in each case, and of why this probability function should play this role. In developing and defending this account, new light is shed on several central epistemological issues. These issues include: the distinction between propositional and doxastic justification; the debates between internalism and externalism, and between foundationalism and coherentism; the significance - or lack of it - of the notion of 'evidence'; the relationship between credences, full belief, inference, and suspension of judgment; the nature of the kind of possibility that is presupposed by the relevant sort of probability; and whether rationality is "diachronic" - so that the beliefs that it is rational for us to have now depend, in part, on the beliefs that we held in the past. Finally, some suggestions are made about how this theory bears on a range of further topics, including the defeasibility of inference, scepticism, and the analysis of knowledge. (shrink)

In this book, Ernest Sosa explains the nature of knowledge through an approach originated by him years ago, known as virtue epistemology. Here he provides the first comprehensive account of his views on epistemic normativity as a form of performance normativity on two levels. On a first level is found the normativity of the apt performance, whose success manifests the performer's competence. On a higher level is found the normativity of the meta-apt performance, which manifests not necessarily first-order skill or (...) competence but rather the reflective good judgment required for proper risk assessment. Sosa develops this bi-level account in multiple ways, by applying it to issues much disputed in recent epistemology: epistemic agency, how knowledge is normatively related to action, the knowledge norm of assertion, and the Meno problem as to how knowledge exceeds merely true belief. A full chapter is devoted to how experience should be understood if it is to figure in the epistemic competence that must be manifest in the truth of any belief apt enough to constitute knowledge. Another takes up the epistemology of testimony from the performance-theoretic perspective. Two other chapters are dedicated to comparisons with ostensibly rival views, such as classical internalist foundationalism, a knowledge-first view, and attributor contextualism. The book concludes with a defense of the epistemic circularity inherent in meta-aptness and thereby in the full aptness of knowing full well. (shrink)

This book takes purism about knowledge as the default position and defends it from the challenges of pragmatic encroachment. The book is divided into two parts, a negative and a positive one. The negative part critically examines existing purist strategies in response to pragmatic encroachment. The positive part provides a new theory of how practical factors can systematically influence our confidence and explores some implications of such influence. In particular, it provides a new purist explanation of the data commonly used (...) to motivate pragmatic encroachment on knowledge. Moreover, it develops a new variety of pragmatic encroachment, not on knowledge but on credence. Thus, my aim in this book is not to provide a full-fledged defence of all kinds of purism. Rather, I argue for purism about knowledge but pragmatic encroachment about credence. This book is a revised version of my PhD dissertation “Belief, Knowledge and Action”. In this revision, I have made some substantive changes, introduced some stylistic changes and added discussions of new relevant literature. (shrink)

What distinguishes full-on stating a proposition from merely communicating it? For instance, what distinguishes claiming/asserting/saying that one has never smoked crack cocaine from merely implying/conveying/hinting this? The enormous literature on ‘assertion’ provides many approaches to distinguishing stating from, say, asking and commanding: only the former aims at truth; only the former expresses one's belief; etc. But this leaves my question unanswered, since in merely communicating a proposition one also aims at truth, expresses a belief, etc. My aim (...) is not to criticize extant accounts of the state-versus-merely-convey contrast, but rather to draw on clues from Dummett, functional linguistics and moral theory, to offer a novel one. The main idea is that full-on stating is distinctively conventionalized in a way that conversationally implicating, hinting, giving to understand, etc., are not. Specifically, full-on stating is constitutively tied to a particular conventional, linguistic, function-bearing device, the declarative sentence. To full-on state that p is to hit that ‘target speech act’ which owes its existence to that special-purpose device. It is therefore also to make one's action lie-prone. Nonetheless, once that sui generis target is there to be aimed for, a person may reach it without using the special-purpose tool—e.g. one may full-on state using a mere word or phrase, or coded hand signals, or semaphore. I end by considering several philosophical implications of this means of capturing the contrast. (shrink)

This paper addresses a largely neglected question in ongoing debates over disagreement: what is the relation, if any, between disagreements involving credences and disagreements involving outright beliefs? The first part of the paper offers some desiderata for an adequate account of credal and full disagreement. The second part of the paper argues that both phenomena can be subsumed under a schematic definition which goes as follows: A and B disagree if and only if the accuracy conditions of A's doxastic (...) attitude are such that, if they were fulfilled, this would ipso facto make B's doxastic attitude inaccurate, or vice-versa. (shrink)

Isaac Levi's new book is concerned with how one can justify changing one's beliefs. The discussion is deeply informed by the belief-doubt model advocated by C. S. Peirce and John Dewey, of which the book provides a substantial analysis. Professor Levi then addresses the conceptual framework of potential changes available to an inquirer. A structural approach to propositional attitudes is proposed, which rejects the conventional view that a propositional attitude involves a relation between an agent and either a linguistic (...) entity or some other intentional object such as a proposition or set of possible worlds. The last two chapters offer an account of change in states of full belief understood as changes in commitments rather than changes in performance; one chapter deals with adding new information to a belief state, the other with giving up information. The book builds upon topics discussed in some of Levi's earlier work. It will be of particular interest to discussion theorists, epistemologists, philosophers of science, computer scientists, and cognitive psychologists. (shrink)

I develop a strategy for representing epistemic states and epistemic changes that seeks to be sensitive to the difference between voluntary and involuntary aspects of our epistemic life, as well as to the role of pragmatic factors in epistemology. The model relies on a particular understanding of the distinction between full belief and acceptance , which makes room for the idea that our reasoning on both practical and theoretical matters typically proceeds in a contextual way. Within this framework, (...) I discuss how agents can rationally shift their credal probability functions so as to consciously modify some of their contextual acceptances; the present account also allows us to represent how the very set of contexts evolves. Voluntary credal shifts, in turn, might provoke changes in the agent’s beliefs, but I show that this is actually a side effect of performing multiple adjustments in the total lot of the agent’s acceptance sets. In this way we obtain a model that preserves many pre-theoretical intuitions about what counts as adequate rationality constraints on our actual practices—and hence about what counts as an adequate, normative epistemological perspective. (shrink)

On the Lockean thesis one ought to believe a proposition if and only if one assigns it a credence at or above a threshold (Foley in Am Philos Q 29(2):111–124, 1992). The Lockean thesis, thus, provides a way of characterizing sets of all-or-nothing beliefs. Here we give two independent characterizations of the sets of beliefs satisfying the Lockean thesis. One is in terms of betting dispositions associated with full beliefs and one is in terms of an accuracy scoring system (...) for full beliefs. These characterizations are parallel to, but not merely derivative from, the more familiar Dutch Book (de Finetti in Theory of probability, vol 1, Wiley, London, 1974) and accuracy (Joyce in Philos Sci 65(4):575–603, 1998) arguments for probabilism. (shrink)

What should we do when faced with powerful theoretical arguments that support a severe change in our personal beliefs and commitments? For example, what should new parents do when confronted by unanswered anti-natalist arguments, or two lovers vexed by social theory that apparently undermines love? On the one hand, it would be irrational to ignore theory just because it’s theory; good theory is evidence, after all. On the other hand, factoring in theory can be objectifying, or risks unraveling one's life, (...) fracturing one's identity or social relations. Sometimes, then, following the evidence where it apparently leads would mean not merely changing what we think but who we are. Some might say that there’s something right about the thought that theory can bear on what we ought to believe, it’s just that when we work with full beliefs, only then do we seriously risk having to substantially alter our doxastic economy when pressed by exceptional theoretical arguments. When we work with partial beliefs, however, this risk is greatly diminished. Others will say that we can advocate or champion revisionary positions whilst rationally retaining our pre-theoretical personal convictions. Still others will argue that we should adopt a Moorean posture towards the revisionary arguments. I argue that each response is inadequate, and argue instead that we are permitted to bracket certain kinds of theoretical evidence against our beliefs because of the personal and ethical risks born out of giving them serious consideration. In turn, some of philosophy's doxastic influence is constrained by its attendant ethical risks: the personal enjoys a partial insulation from the theoretical. I close by addressing what this means for practicing philosophers. (shrink)

T. J. Mawson's highly readable and engaging new introduction to the philosophy of religion offers full coverage of the key issues, from ideas about God's nature and character to arguments for and against His existence. Mawson's conversational style, lively wit, and enlightening examples make Belief in God as pleasurable as it is instructive and thought-provoking. It makes an ideal text for beginning undergraduate courses and for anyone thinking about these most important of questions.

Probabilistic belief contraction has been a much neglected topic in the field of probabilistic reasoning. This is due to the difficulty in establishing a reasonable reversal of the effect of Bayesian conditionalization on a probabilistic distribution. We show that indifferent contraction, a solution proposed by Ramer to this problem through a judicious use of the principle of maximum entropy, is a probabilistic version of a full meet contraction. We then propose variations of indifferent contraction, using both the Shannon (...) entropy measure as well as the Hartley entropy measure, with an aim to avoid excessive loss of beliefs that full meet contraction entails. (shrink)

Wolfgang Spohn presents the first full account of the dynamic laws of belief, by means of ranking theory. This book is his long-awaited presentation of ranking theory and its ramifications.

Probabilism says an agent is rational only if her credences are probabilistic. This paper is concerned with the so-called Accuracy Dominance Argument for Probabilism. This argument begins with the claim that the sole fundamental source of epistemic value for a credence is its accuracy. It then shows that, however we measure accuracy, any non-probabilistic credences are accuracy-dominated: that is, there are alternative credences that are guaranteed to be more accurate than them. It follows that non-probabilistic credences are irrational. In this (...) paper, I identify and explore a lacuna in this argument. I grant that, if the only doxastic attitudes are credal attitudes, the argument succeeds. But many philosophers say that, alongside credences, there are other doxastic attitudes, such as full beliefs. What's more, those philosophers typically claim, these other doxastic attitudes are closely connected to credences, either as a matter of necessity or normatively. Now, since full beliefs are also doxastic attitudes, it seems that, like credences, the sole source of epistemic value for them is their accuracy. Thus, if we wish to measure the epistemic value of an agent's total doxastic state, we must include not only the accuracy of her credences, but also the accuracy of her full beliefs. However, if this is the case, there is a problem for the Accuracy Dominance Argument for Probabilism. For all the argument says, there might be non-probabilistic credences such that there is no total doxastic state that accuracy-dominates the total doxastic state to which those credences belong. (shrink)

When a new piece of information contradicts a currently held belief, one has to modify the set of beliefs in order to restore its consistency. In the case where it is necessary to give up a belief, some of them are less likely to be abandoned than others. The concept of epistemic entrenchment is used by some AI approaches to explain this fact based on formal properties of the belief set (e.g., transitivity). Two experiments were designed to (...) test the hypothesis that contrary to such views, (i) belief is naturally represented by degrees rather than in an all-or-nothing manner, (ii) entrenchment is primarily a matter of content and not only a matter of form, and (iii) consequently prior degree of belief is a powerful factor of change. The two experiments used Elio and Pelletier's (1997) paradigm in which participants were presented with full simple deductive arguments whose conclusion was denied, following which they were asked to decide which premise to revise. (shrink)

As the content of propositional attitudes, propositions are usually taken to help explain the behavior of rational agents. However, a closer look at signaling games suggests otherwise: rational agents often acquire partial beliefs, and many of their signals are ambiguous. Signaling games also suggest that it is rational for agents to mix their behavior in response to partial beliefs and ambiguous signals. But as I show in this paper, propositions cannot help explain the mixing behavior of rational agents: to explain (...) mixing behavior, we need a probabilistic notion of content. I also show that a probabilistic notion of content renders propositions explanatorily idle in the case of unambiguous signals and full beliefs as well. My suggestion is thus that we should abandon propositions in explanations of rational behavior and adopt instead a probabilistic notion of content. The notion of probabilistic content ultimately provides a simpler framework for explanations of rational behavior than the notion of propositional content. (shrink)

We show how to construct partial nontrivial base revision operators that satisfy the analogues of the AGM postulates and depends on no extra‐logical consideration. These operators, closely related to the full meet revision process, are defined on stratified bases, in which the information can be ranked in logical sequences. Stratified bases, which can be viewed as sets of graded sheaves, are exactly the knowledge bases for which the full meet revision operator satisfies the rationality postulate K*8. As the (...) revision of a stratified base is again a stratified base, it is possible to perform iterated revisions, and the resulting output is particularly easy to determine. (shrink)

We discuss various possibilities for developing a dynamic doxastic logic (DDL) for introspective agents: agents who have the ability to form higher-order beliefs. Such agents can reflect upon and change their minds about their own beliefs. The project of constructing such a logic, full DDL or DDL unlimited, is ridden with difficulties due to the fact that the agent's own doxastic state now becomes a part of the reality he is trying to explore. When an introspective agent learns more (...) about the world (and himself), the reality he holds beliefs about undergoes a change in its doxastic part, which means that his introspective beliefs have to be adjusted accordingly. (shrink)

This study investigates the characteristics of posttraumatic growth (PTG) and academic burnout among adolescents in an ethnic minority area in China during the COVID-19 pandemic, and examines the moderating role of core belief challenge on the association between PTG and academic burnout. This study surveyed 941 secondary school students in Wenchuan using the posttraumatic growth inventory, adolescent academic burnout inventory, core beliefs inventory, and a self-designed demographic questionnaire. The results showed that: (1) Five months after the COVID-19 outbreak in (...) China, the level of PTG among adolescents in the Wenchuan area was high and its prevalence was 32.3%. Among them, the dimension of perceived changes in self was the highest, and the PTG level of junior high school students was higher than that of high school students. The academic burnout level of adolescents, particularly emotional exhaustion, was also high. The academic burnout level of the high school students was higher than that of junior high school students. (2) There was a significant negative correlation between PTG and academic burnout among adolescents. (3) Core belief challenge moderated the relationship between PTG and academic burnout. PTG had a significant negative predictive effect on adolescents’ academic burnout only when the core belief challenge was above a moderate level. These results showed the uniqueness of PTG and psychological behavioral problems of adolescents in ethnic minority areas during the COVID-19 pandemic. They also emphasized the key role of core belief challenge in the process of PTG in reducing adolescents’ academic burnout. Based on these results, recommendations are provided to alleviate academic burnout among adolescents in Wenchuan against the background of the COVID-19 pandemic. While providing full play to ethnic minority cultural characteristics to promote posttraumatic growth, guiding adolescents’ value reflection and cognitive reconstruction should be focused on. (shrink)

How are beliefs efficacious? One answer is: via rational intentional action. But there are other ways that beliefs are efficacious. This dissertation examines these other ways, and sketches an answer to the question of how beliefs are efficacious that takes into account how beliefs are involved in the full range of behavioral disciplines, from psychophysiology and cognition to social and economic phenomena. The account of how beliefs are efficacious I propose draws on work on active accounts of perception. I (...) develop an account based on a proposal sketched by the cognitive scientist Ulrich Neisser. Neisser sketched an active account of perception, on which dynamic anticipatory schemata direct an organism's exploration and action, and are in turn revised as a result of exploration and action. This notion of schema has roots in nineteenth century neurophysiology and in Frederick Bartlett's subsequent work on memory. Neisser appealed to it to unite what he thought was right about information-processing accounts of perception with what he thought was right about ecological accounts of perception. The point that we must anticipate in order to perceive has been recognized by philosophers in the form of the "theory-ladenness of observation." I extend the concept of anticipatory schema to include its role in social perception and social interaction; the concept of anticipatory schema provides a more interactive account of the role of expectations in the maintenance and existence of social institutions, and can be used to enrich the account of convention David Lewis provided. I also show that the concept of rational expectations, which explains the neutrality of money in terms of the efficacy of anticipatory expectations, is compatible with the proposed account of how beliefs are efficacious. I discuss how the proposal accounts for the three main modes by which beliefs can be efficacious: via their role in causing intentional action, via their role in causing economic phenomena and the existence and maintenance of social institutions, and via their role in causing unintentional physiological responses, including anticipatory physiological responses that can enable perception, cause involuntary actions and give rise to the placebo effect. (shrink)

Probabilism says an agent is rational only if her credences are probabilistic. This paper is concerned with the so-called Accuracy Dominance Argument for Probabilism. This argument begins with the claim that the sole fundamental source of epistemic value for a credence is its accuracy. It then shows that, however we measure accuracy, any non-probabilistic credences are accuracy-dominated: that is, there are alternative credences that are guaranteed to be more accurate than them. It follows that non-probabilistic credences are irrational. In this (...) paper, I identify and explore a lacuna in this argument. I grant that, if the only doxastic attitudes are credal attitudes, the argument succeeds. But many philosophers say that, alongside credences, there are other doxastic attitudes, such as full beliefs. What's more, those philosophers typically claim, these other doxastic attitudes are closely connected to credences, either as a matter of necessity or normatively. Now, since full beliefs are also doxastic attitudes, it seems that, like credences, the sole source of epistemic value for them is their accuracy. Thus, if we wish to measure the epistemic value of an agent's total doxastic state, we must include not only the accuracy of her credences, but also the accuracy of her full beliefs. However, if this is the case, there is a problem for the Accuracy Dominance Argument for Probabilism. For all the argument says, there might be non-probabilistic credences such that there is no total doxastic state that accuracy-dominates the total doxastic state to which those credences belong. (shrink)

We study belief change in the branching-time structures introduced in Bonanno (Artif Intell 171:144–160, 2007 ). First, we identify a property of branching-time frames that is equivalent (when the set of states is finite) to AGM-consistency, which is defined as follows. A frame is AGM-consistent if the partial belief revision function associated with an arbitrary state-instant pair and an arbitrary model based on that frame can be extended to a full belief revision function that satisfies the (...) AGM postulates. Second, we provide a set of modal axioms that characterize the class of AGM-consistent frames within the modal logic introduced in Bonanno (Artif Intell 171:144–160, 2007 ). Third, we introduce a generalization of AGM belief revision functions that allows a clear statement of principles of iterated belief revision and discuss iterated revision both semantically and syntactically. (shrink)

It is now well known that, on pain of triviality, the probability of a conditional cannot be identified with the corresponding conditional probability [25]. This surprising impossibility result has a qualitative counterpart. In fact, Peter Gärdenfors showed in [13] that believing ‘If A then B’ cannot be equated with the act of believing B on the supposition that A — as long as supposing obeys minimal Bayesian constraints. Recent work has shown that in spite of these negative results, the question (...) ‘how to accept a conditional?’ has a clear answer. Even if conditionals are not truth-carriers, they do have precise acceptability conditions. Nevertheless most epistemic models of conditionals do not provide acceptance conditions for iterated conditionals. One of the main goals of this essay is to provide a comprehensive account of the notion of epistemic conditionality covering all forms of iteration. First we propose an account of the basic idea of epistemic conditionality, by studying the conditionals validated by epistemic models where iteration is permitted but not constrained by special axioms. Our modeling does not presuppose that epistemic states should be represented by belief sets (we only assume that to each epistemic state corresponds an associated belief state). A full encoding of the basic epistemic conditionals (encompassing all forms of iteration) is presented and a representation result is proved. In the second part of the essay we argue that the notion of change involved in the evaluation of conditionals is suppositional, and that such notion should be distinguished from the notion of updating (modelled by AGM and other methods). We conclude by considering how some of the recent modellings of iterated change fare as methods for iterated supposing. (shrink)

Deontic modals are the topic of my dissertation. All deontic modals, yes, but justification in particular, and epistemic justification even more specifically. Deontic modals operate upon performances—they appraise performances. Positively appraised, a performance is appropriate, decent, justifiable, right, permissible, or proper; negatively appraised, inappropriate, indecent, unjustifiable, wrong, impermissible, or improper. Belief and knowledge and performances in exactly the same sense that action and intention are performances: all are products of powers that are in some sense responsive to reasons. The (...) principal difference is the direction of fit between mind and world. Knowledge and belief the product of cognitive powers aimed at adapting mind to world, action and intention the product of conative powers aimed at adapting world to mind. All are normatively evaluable and the characteristic normative appraisal of each is deontic. Epistemology, ethics, and rational choice all investigate the nature of deontic modals, differing only insofar as the central aims are epistemic, moral, or prudential in nature. In this sense, the general theory of deontic modals is the parent to epistemology, ethics, and rational choice. My project is to develop and defend a schematic theory of justification. I achieve this end by developing and defending a general theory of deontic modalities. Riffing on two pithy turns of phrase, the deontic theory may be tersely sloganized: value first and one must do the best one can. It is a teleological theory that defines all deontic concepts from the theoretically foundational notions of ability and value. Roughly, a belief is epistemically justifiable if, and only if, it is part of an epistemically optimific belief set the agent is able to have. Roughly, an act is morally justifiably if, and only if, it is part of a morally optimific action set the agent is able to perform. My pet interest is in the former. The resultant framework is enormously fruitful, especially in epistemology. (shrink)

The theory of belief revision deals with (rational) changes in beliefs in response to new information. In the literature a distinction has been drawn between belief revision and belief update (see [6]). The former deals with situations where the objective facts describing the world do not change (so that only the beliefs of the agent change over time), while the letter allows for situations where both the facts and the doxastic state of the agent change over time. (...) We focus on belief revision and propose a temporal framework that allows for iterated revision. We model the notion of “minimal” or “conservative” belief revision by considering logics of increasing strength. We move from one logic to the next by adding one or more axioms and show that the corresponding logic captures more stringent notions of minimal belief revision. The strongest logic that we propose provides a full axiomatization of the well-known AGM theory of belief revision. (shrink)

The paper provides some observations that support the view, such as with Nathan Salmon, that we have full substitutivity of coextensional names in belief contexts. Further, the paper notes some consequences for doxastic modalites in an induced Millian logic of belief.

Evidentialism implies that, for epistemic purposes, belief should be responsive only to evidence. Focusing on our reactive attitude such as resentment or indignation, I construct an argument that the beliefs or judgments accompanying those attitudes are constrained in advance by circumstances to be full, rather than being open to the whole range of partial beliefs. These judgments or beliefs imply strong claims to justification. But the circumstances in which those attitudes are formed allow only very limited evidence. Nevertheless, (...) we cannot opt out regularly since the formation of such attitudes is so central a feature of a minimally content human social life. (shrink)

What is the relationship between degrees of belief and binary beliefs? Can the latter be expressed as a function of the former—a so-called “belief-binarization rule”—without running into difficulties such as the lottery paradox? We show that this problem can be usefully analyzed from the perspective of judgment-aggregation theory. Although some formal similarities between belief binarization and judgment aggregation have been noted before, the connection between the two problems has not yet been studied in full generality. In (...) this paper, we seek to fill this gap. The paper is organized around a baseline impossibility theorem, which we use to map out the space of possible solutions to the belief-binarization problem. Our theorem shows that, except in limiting cases, there exists no belief-binarization rule satisfying four initially plausible desiderata. Surprisingly, this result is a direct corollary of the judgment-aggregation variant of Arrow’s classic impossibility theorem in social choice theory. (shrink)

Testimony poses a challenge to systematic epistemology. I cite two kinds of testimony situation where the recipient's belief is not safe, yet intuitively counts as knowledge. Can Sosa's more sophisticated virtue reliabilism, which theorises animal knowledge as apt belief, yield the intuitively correct verdict on these cases? Sosa shows that a belief can be apt, though it is not safe, and so it may seem a quick positive answer is forthcoming. However, I explore complications in applying his (...) AAA framework, regarding what we take as the circumstances in which the subject's attempt is made: the AAA framework does not mandate a particular choice, yet this affects whether the attempt comes out as apt or not. I conclude that Sosa's theory is subject to a familiar charge: it does not give a reductive account of knowledge, since we must deploy independent intuitions about whether knowledge is gained in a case, in order to apply it. (shrink)

This volume is a collection of original essays by eminent philosophers written for R. B. Braithwaite's eightieth birthday to celebrate his work and teaching. In one way or another, all the essays reflect his central concern with the impact of science on our beliefs about the world and the responses appropriate to that. Together they testify to the signal importance of his contributions in areas of philosophy bearing on this concern: the philosophy of science, especially of the statistical sciences, theories (...) of belief and of probability, decision theory and games theory. This book, which includes a full bibliography of Professor Braithwaite's work, will interest advanced students and professionals in the fields of philosophy and psychology. (shrink)