Do people tend to be overconfident? Many think so. They’ve run studies on whether people are calibrated: whether their average confidence in their opinions matches the proportion of those opinions that are true. Under certain conditions, people are systematically ‘over-calibrated’—for example, of the opinions they’re 80% confident in, only 60% are true. From this empirical over-calibration, it’s inferred that people are irrationally overconfident. My question: When and why is this inference warranted? Answering it requires articulating a general connection between being (...) rational and being right—something extant studies have not done. I show how to do so using the notion of deference. This provides a theoretical foundation for calibration research, but also reveals a flaw: the connection between being rational and being right is much weaker than is standardly assumed, since rational people can often be expected to be miscalibrated. Thus we can’t test whether people are overconfident by simply testing whether they are over-calibrated; instead, we must try to predict the rational deviations from calibration, and then compare those predictions to people’s performance. I show how this can be done—and that doing so complicates the interpretation of robust empirical effects. (shrink)

Kysymys siitä, onko tiede ja voiko se olla arvovapaata, on herättänyt vilkasta ja jopa kiivastakin keskustelua. Erityisen polttava tämä kysymys on ihmistieteissä. Yhdessä ääripäässä on kuva tieteellisestä tutkimuksesta kaikenlaisten eettisten ja yhteiskunnallisten kysymysten yläpuolella olevana intressittömänä toimintana. Toisessa päässä on väite, ettei tiede voi koskaan olla arvovapaata vaan että tieteellinen tutkimus ja sen tulokset ovat läpeensä arvojen värittämiä. Näiden välille mahtuu monenlaisia maltillisempia välittäviä kantoja.

Various theories try to give accounts of how measures of this confidence do or ought to behave, both as far as the internal mental consistency of the agent as ...

This paper presents a theory of conclusions based upon the suggestions of Tukey [21]. The logic offered here is based upon two rules of detachment that occur naturally in probabilistic inference, a traditional rule of acceptance, and a rule of rejection. The rules of detachment provide flexibility: the theory of conclusions can account for both statistical and deductive arguments. The rule of acceptance governs the acceptance of new conclusions, is a variant of the rule of high probability, and is a (...) limiting case of a decision-theoretic rule of acceptance. The rule of rejection governs the removal of previously accepted conclusions on the basis of new evidence. The resulting theory of conclusions is not a decision-theoretic logic but does, through the aforementioned limiting property, provide a line of demarcation between decision and conclusion (i.e., nondecision) logics of acceptance. The theory of conclusions therefore complements decision-theoretic inference. The theory of conclusions presented here satisfies Tukey's desiderata, specifically: (1) conclusions are statements which are accepted on the basis of unusually strong evidence; (2) conclusions are to remain accepted unless and until unusually strong evidence to the contrary arises; (3) conclusions are subject to future rejection, when and if the evidence against them becomes strong enough. Finally, the proferred theory of conclusions has a strong conservative bias, reflecting Tukey's aims. (shrink)

The Preface Paradox apparently shows that it is sometimes rational to believe logically incompatible propositions. In this paper, I propose a way out of the paradox based on the ideas of fallibilism and verisimilitude. More precisely, I defend the view that a rational inquirer can fallibly believe or accept a proposition which is false, or likely false, but verisimilar; and I argue that this view makes the Preface Paradox disappear. Some possible objections to my proposal, and an alternative view of (...) fallible belief, are briefly discussed in the final part of the paper. (shrink)

It is sometimes said that faith is recalcitrant in the face of new evidence, but it is puzzling how such recalcitrance could be rational or laudable. I explain this aspect of faith and why faith is not only rational, but in addition serves an important purpose in human life. Because faith requires maintaining a commitment to act on the claim one has faith in, even in the face of counter-evidence, faith allows us to carry out long-term, risky projects that we (...) might otherwise abandon. Thus, faith allows us to maintain integrity over time. (shrink)

In the peer disagreement debate, three intuitively attractive claims seem to conflict: there is disagreement among peers on many important matters; peer disagreement is a serious challenge to one’s own opinion; and yet one should be able to maintain one’s opinion on important matters. I show that contrary to initial appearances, we can accept all three of these claims. Disagreement significantly shifts the balance of the evidence; but with respect to certain kinds of claims, one should nonetheless retain one’s beliefs. (...) And one should retain them even though these beliefs would not be supported by the new total evidence if one didn’t already hold them. (shrink)

Probabilistic dependence and independence are among the key concepts of Bayesian epistemology. This paper focuses on the study of one specific quantitative notion of probabilistic dependence. More specifically, section 1 introduces Keynes’s coefficient of dependence and shows how it is related to pivotal aspects of scientific reasoning such as confirmation, coherence, the explanatory and unificatory power of theories, and the diversity of evidence. The intimate connection between Keynes’s coefficient of dependence and scientific reasoning raises the question of how Keynes’s coefficient (...) of dependence is related to truth, and how it can be made fruitful for epistemological considerations. This question is answered in section 2 of the paper. Section 3 outlines the consequences the results have for epistemology and the philosophy of science from a Bayesian point of view. (shrink)

In this paper we show that the coherence measures of Olsson (J Philos 94:246–272, 2002), Shogenji (Log Anal 59:338–345, 1999), and Fitelson (Log Anal 63:194–199, 2003) satisfy the two most important adequacy requirements for the purpose of assessing theories. Following Hempel (Synthese 12:439–469, 1960), Levi (Gambling with truth, New York, A. A. Knopf, 1967), and recently Huber (Synthese 161:89–118, 2008) we require, as minimal or necessary conditions, that adequate assessment functions favor true theories over false theories and true and informative (...) theories over true but uninformative theories. We then demonstrate that the coherence measures of Olsson, Shogenji, and Fitelson satisfy these minimal conditions if we confront the hypotheses with a separating sequence of observational statements. In the concluding remarks we set out the philosophical relevance, and limitations, of the formal results. Inter alia, we discuss the problematic implications of our precondition that competing hypotheses must be confronted with a separating sequence of observational statements, which also leads us to discuss theory assessment in the context of scientific antirealism. (shrink)

Traditionally scientific rationality has been distinguished from mere practical rationality. It has seemed that it is sometimes rational to accept statements for the purposes of particular practical deliberations even though it would not be rational to count them as having been confirmed by science. Isaac Levi contends that this traditional view is mistaken. He thinks that there should be a single standard of acceptance for all purposes, scientific and practical. The author contends that Levi has given no good reason for (...) identifying scientific with practical rationality. And he argues that Levi's own theory is inconsistent with the thesis that a scientist should use a single standard of acceptance in all his scientific deliberations. (shrink)

I propose a general alethic theory of epistemic risk according to which the riskiness of an agent’s credence function encodes her relative sensitivity to different types of graded error. After motivating and mathematically developing this approach, I show that the epistemic risk function is a scaled reflection of expected inaccuracy. This duality between risk and information enables us to explore the relationship between attitudes to epistemic risk, the choice of scoring rules in epistemic utility theory, and the selection of priors (...) in Bayesian epistemology more generally. (shrink)

Degrees of belief are familiar to all of us. Our confidence in the truth of some propositions is higher than our confidence in the truth of other propositions. We are pretty confident that our computers will boot when we push their power button, but we are much more confident that the sun will rise tomorrow. Degrees of belief formally represent the strength with which we believe the truth of various propositions. The higher an agent’s degree of belief for a particular (...) proposition, the higher her confidence in the truth of that proposition. For instance, Sophia’s degree of belief that it will be sunny in Vienna tomorrow might be .52, whereas her degree of belief that the train will leave on time might be .23. The precise meaning of these statements depends, of course, on the underlying theory of degrees of belief. These theories offer a formal tool to measure degrees of belief, to investigate the relations between various degrees of belief in different propositions, and to normatively evaluate degrees of belief. (shrink)

This paper combines various structures representing degrees of belief, degrees of disbelief, and degrees of non-belief (degrees of expectations) into a unified whole. The representation uses relations of comparative necessity and possibility, as well as non-probabilistic functions assigning numerical values of necessity and possibility. We define all-encompassing necessity structures which have weak expectations (mere hypotheses, guesses, conjectures, etc.) occupying the lowest ranks and very strong, ineradicable ('a priori') beliefs occupying the highest ranks. Structurally, there are no differences from the top (...) to the bottom. I argue that belief is a vague notion, and that thresholds for belief, if there are any, are context-dependent. (shrink)

The standard way of representing an epistemic state in formal philosophy is in terms of a set of sentences, corresponding to the agent’s beliefs, and an ordering of those sentences, reflecting how well entrenched they are in the agent’s epistemic state. We argue that this wide-spread representational view – a view that we identify as a “Quinean dogma” – is incapable of making certain crucial distinctions. We propose, as a remedy, that any adequate representation of epistemic states must also include (...) the agent’s research agenda, i.e., the list of question that are open or closed at any given point in time. If the argument of the paper is sound, a person’s questions and practical interests, on the one hand, and her beliefs and theoretical values, on the other, are more tightly interwoven than has previously been assumed to be the case in formal epistemology. (shrink)

This book examines the philosophical conception of abductive reasoning as developed by Charles S. Peirce, the founder of American pragmatism. It explores the historical and systematic connections of Peirce's original ideas and debates about their interpretations. Abduction is understood in a broad sense which covers the discovery and pursuit of hypotheses and inference to the best explanation. The analysis presents fresh insights into this notion of reasoning, which derives from effects to causes or from surprising observations to explanatory theories. The (...) author outlines some logical and AI approaches to abduction as well as studies various kinds of inverse problems in astronomy, physics, medicine, biology, and human sciences to provide examples of retroductions and abductions. The discussion covers also everyday examples with the implication of this notion in detective stories, one of Peirce’s own favorite themes. The author uses Bayesian probabilities to argue that explanatory abduction is a method of confirmation. He uses his own account of truth approximation to reformulate abduction as inference which leads to the truthlikeness of its conclusion. This allows a powerful abductive defense of scientific realism. This up-to-date survey and defense of the Peircean view of abduction may very well help researchers, students, and philosophers better understand the logic of truth-seeking. (shrink)

The paper provides an alternative interpretation of ‘pair points’, discussed in Beall et al., "On the ternary relation and conditionality", J. of Philosophical Logic 41(3), 595-612. Pair points are seen as points viewed from two different ‘perspectives’ and the latter are explicated in terms of two independent valuations. The interpretation is developed into a semantics using pairs of Kripke models (‘pair models’). It is demonstrated that, if certain conditions are fulfilled, pair models are validity-preserving copies of positive substructural models. This (...) yields a general soundness and completeness result for a variety of (positive) substructural logics with respect to multimodal Kripke frames with binary accessibility relations. In addition, an epistemic interpretation of pair models is provided. (shrink)

In this paper, I examine the possibility of accounting for the rationality of belief-formation by utilising decision-theoretic considerations. I consider the utilities to be used by such an approach, propose to employ verisimilitude as a measure of cognitive utility, and suggest a natural way of generalising any measure of verisimilitude defined on propositions to partial belief-systems, a generalisation which may enable us to incorporate Popper's insightful notion of verisimilitude within a Bayesian framework. I examine a dilemma generated by the decision-theoretic (...) procedure and consider an adequacy condition (immodesty) designed to ameliorate one of its horns. Finally, I argue in a sceptical vein that no adequate verisimilitude measure can be used decision-theoretically. (shrink)

A seemingly plausible application of Bayesian decision-theoretic reasoning to determine one's rational degrees of belief yields a paradoxical conclusion: one ought to jettison one's intermediate credences in favour of more extreme (opinionated) ones. I discuss various attempts to solve the paradox, those involving the acceptance of the paradoxical conclusion, and those which attempt to block its derivation.

The present article illustrates a conflict between the claim that rational belief sets are closed under deductive consequences, and a very inclusive claim about the factors that are sufficient to determine whether it is rational to believe respective propositions. Inasmuch as it is implausible to hold that the factors listed here are insufficient to determine whether it is rational to believe respective propositions, we have good reason to deny that rational belief sets are closed under deductive consequences.

The rule of adjunction is intuitively appealing and uncontroversial for deductive inference, but in situations where information can be uncertain, the rule is neither needed nor wanted for rational acceptance, as illustrated by the lottery paradox. Practical certainty is the acceptance of statements whose chances of error are smaller than a prescribed threshold parameter, when evaluated against an evidential corpus. We examine the failure of adjunction in relation to the threshold parameter for practical certainty, with an eye towards reinstating the (...) rule of adjunction in some restricted forms, by observing the conditions under which the overall chance of error of the joint statements can be variously bounded. (shrink)

In “What price coherence?”, Klein and Warfield put forward a simple argument that triggered an extensive debate on the epistemic virtues of coherence. As is well-known, this debate yielded far-reaching impossibility results to the effect that coherence is not conducive to truth, even if construed in a ceteris paribus sense. A large part of the present paper is devoted to a re-evaluation of these results. As is argued, all explications of truth-conduciveness leave out an important aspect: while it might not (...) be the case that coherence is truth-conducive, it might be conducive to verisimilitude or epistemic utility. Unfortunately, it is shown that the answer for both these issues must be in the negative, again. Furthermore, we shift the focus from sets of beliefs to particular beliefs: as is shown, neither is any of the extant probabilistic measures of coherence truth-conducive on the level of particular beliefs, nor does weakening these measures to quasi-orderings establish the link between coherence and truth for an important amount of measures. All in all, the results in this paper cast a serious doubt on the approach of establishing a link between coherence and truth. Finally, recent arguments that shift the focus from the relationship between coherence and truth to the one between coherence and confirmation are assessed. (shrink)

There are two ways of representing rational belief: qualitatively as yes-or-no belief, and quantitatively as degrees of belief. Standard rationality conditions are: consistency and logical closure, for qualitative belief, satisfaction of the probability axioms, for quantitative belief, and a relationship between qualitative and quantitative beliefs in accordance with the Lockean thesis. In this paper, it is shown that these conditions are inconsistent with each of three further rationality conditions: fallibilism, open-mindedness, and invariance under independent conceptual expansions. Restrictions of the Lockean (...) thesis that have been suggested in the literature cannot remove the inconsistency. In the outlook we discuss two alternative ways of dealing with this problem: restricting conjunctive closure or going for a dual system account. (shrink)

Critical Notice of Kant's Transcendental Deduction, by Henry Allison. Oxford: Oxford University Press, 2015. Pp. Xv + 477.

According to the Ramsey Test, conditionals reflect changes of beliefs: α > β is accepted in a belief state iff β is accepted in the minimal revision of it that is necessary to accommodate α. Since Gärdenfors’s seminal paper of 1986, a series of impossibility theorems (“triviality theorems”) has seemed to show that the Ramsey test is not a viable analysis of conditionals if it is combined with AGM-type belief revision models. I argue that it is possible to endorse that (...) Ramsey test for conditionals while staying true to the spirit of AGM. A main focus lies on AGM’s condition of Preservation according to which the original belief set should be fully retained after a revision by information that is consistent with it. I use concrete representations of belief states and (iterated) revisions of belief states as semantic models for (nested) conditionals. Among the four most natural qualitative models for iterated belief change, two are identified that indeed allow us to combine the Ramsey test with Preservation in the language containing only flat conditionals of the form α > β. It is shown, however, that Preservation for this simple language enforces a violation of Preservation for nested conditionals of the form α > (β > γ). In such languages, no two belief sets are ordered by strict subset inclusion. I argue that it has been wrong right from the start to expect that Preservation holds in languages containing nested conditionals. (shrink)

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)

Famously, William James held that there are two commandments that govern our epistemic life: Believe truth! Shun error! In this paper, I give a formal account of James' claim using the tools of epistemic utility theory. I begin by giving the account for categorical doxastic states – that is, full belief, full disbelief, and suspension of judgment. Then I will show how the account plays out for graded doxastic states – that is, credences. The latter part of the paper thus (...) answers a question left open in Pettigrew. (shrink)

My concern in this paper is a debate between Pascal Engel and Richard Rorty documented in the book What’s the Use of Truth? Both Engel and Rorty problematize the natural suggestion that attaining truth is a goal of our inquiries. Where Rorty thinks this means that truth is not something we should aim for at all over and beyond justification, Engel maintains that truth still plays a distinct role in our intellectual and daily lives. Thus, the debate between Engel and (...) Rorty ends in a standoff. In the present paper, I question the claim that truth is not a goal of inquiry. I do so from the point of view of a systematic and general theory of rational goal-setting which has its roots in management science. I argue, in this connection, that Rorty’s central claim rests on a principle of goal-setting rationality that is generally invalid. The bottom line is that the goal of truth, like other visionary goals, is likely to have the positive effect of increasing motivation and effort, and this may offset the drawbacks which Rorty, rightly, calls attention to. In largely following Rorty in this regard, Engel is making one concession too much to his opponent. (shrink)

Isaac Levi has claimed that our reliance on the testimony of others, and on the testimony of the senses, commonly produces inconsistency in our set of full beliefs. This happens if what is reported is inconsistent with what we believe to be the case. Drawing on a conception of the role of beliefs in inquiry going back to Dewey, Levi has maintained that the inconsistent belief corpus is a state of ``epistemic hell'': it is useless as a basis for inquiry (...) and deliberation. As he has also noticed, the compatibility of these two elements of his pragmatist epistemology could be called into question. For if inconsistency means hell, how can it ever be rational to enter that state, and on what basis could we attempt to regain consistency? Levi, nonetheless, has tried to show that the conflict is only apparent and that no changes of his theory are necessary. In the main part of the paper I argue, by contrast, that his attempts to reconcile these components of his view are unsuccessful.The conflict is real andthus presents a genuine threat to Deweyan pragmatism, as understood by Levi. After an attempt to pinpoint exactly where the source of the problem lies, I explore some possibilities for how to come to grips with it. I conclude that Levi can keep his fundamental thesis concerning the role of beliefs in inquiry and deliberation, provided that he (i) gives up the view that the agent can legitimately escape from inconsistency, and (ii) modifies his account of prediction alias deliberate expansion by acknowledging a third desideratum, besides probability and informational value, namely, not to cause permanent breakdown further down the line of inquiry. The result is a position which is more similar to Peter Gärdenfors's than is Levi's original theory, while retaining the basic insights of the latter. (shrink)

Isaac Levi has claimed that our reliance on the testimony of others, and on the testimony of the senses, commonly produces inconsistency in our set of full beliefs. This happens if what is reported is inconsistent with what we believe to be the case. Drawing on a conception of the role of beliefs in inquiry going back to Dewey, Levi has maintained that the inconsistent belief corpus is a state of ``epistemic hell'': it is useless as a basis for inquiry (...) and deliberation. As he has also noticed, the compatibility of these two elements of his pragmatist epistemology could be called into question. For if inconsistency means hell, how can it ever be rational to enter that state, and on what basis could we attempt to regain consistency? Levi, nonetheless, has tried to show that the conflict is only apparent and that no changes of his theory are necessary. In the main part of the paper I argue, by contrast, that his attempts to reconcile these components of his view are unsuccessful.The conflict is real andthus presents a genuine threat to Deweyan pragmatism, as understood by Levi. After an attempt to pinpoint exactly where the source of the problem lies, I explore some possibilities for how to come to grips with it. I conclude that Levi can keep his fundamental thesis concerning the role of beliefs in inquiry and deliberation, provided that he (i) gives up the view that the agent can legitimately escape from inconsistency, and (ii) modifies his account of prediction alias deliberate expansion by acknowledging a third desideratum, besides probability and informational value, namely, not to cause permanent breakdown further down the line of inquiry. The result is a position which is more similar to Peter Gärdenfors's than is Levi's original theory, while retaining the basic insights of the latter. (shrink)

Susan Mills and John Beatty's propensity interpretation of fitness encountered very different philosophical criticisms by Alexander Rosenberg and Kenneth Waters. These criticisms and the rejoinders to them are both predictable and important. They are predictable as raisingkinds of issues typically associated with disposition concepts (this is established through a systematic review of the problems generated by Carnap's dispositional interpretation of all scientific terms). They are important as referring the resolution of these issues to the development of evolutionary biology. This historical (...) approach to the propensity interpretation of fitness draws attention to the precarious relation between philosophical clarification of scientific concepts and any given state of the empirical arts. (shrink)

The notion of truthlikeness or verisimilitude has been a topic of intensive discussion ever since the definition proposed by Karl Popper was refuted in 1974. This paper gives an analysis of old and new debates about this notion. There is a fairly large agreement about the truthlikeness ordering of conjunctive theories, but the main rival approaches differ especially about false disjunctive theories. Continuing the debate between Niiniluoto’s min-sum measure and Schurz’s relevant consequence measure, the paper also gives a critical assessment (...) of Oddie’s new defense of the average measure and Kuipers’ refined definition of truth approximation. (shrink)

The notion of truthlikeness or verisimilitude has been a topic of intensive discussion ever since the definition proposed by Karl Popper was refuted in 1974. This paper gives an analysis of old and new debates about this notion. There is a fairly large agreement about the truthlikeness ordering of conjunctive theories, but the main rival approaches differ especially about false disjunctive theories. Continuing the debate between Niiniluoto’s min-sum measure and Schurz’s relevant consequence measure, the paper also gives a critical assessment (...) of Oddie’s new defense of the average measure and Kuipers’ refined definition of truth approximation. (shrink)

While most philosophers of science agree that science is, perhaps in many ways, a highly successful enterprise, there is no consensus about the best way of defining and measuring this success. Philosophers are also divided in their views about two further issues: What does the success of a scientific theory indicate? What is the best way of explaining this success?After some remarks about institutional and pragmatic measures of success, this paper concentrates on rival ways of defining cognitive success. Four realist (...) measures of epistemic credit are discussed: probability, confirmation (corroboration), expected verisimilitude, and probable verisimilitude. Laudan’s non-realist concept of the problem-solving effectiveness of a theory is compared to Hempel’s notion of systematic power. I argue that such truth-independent concepts alone are insufficient to characterize scientific advance. But if they are used as truth-dependent epistemic utilities, they serve as fallible indicators of the truth or truthlikeness of a theory. (shrink)

I argue that considerations about computational complexity show that all finite agents need characteristics like those that have been called epistemic virtues. The necessity of these virtues follows in part from the nonexistence of shortcuts, or efficient ways of finding shortcuts, to cognitively expensive routines. It follows that agents must possess the capacities – metavirtues –of developing in advance the cognitive virtues they will need when time and memory are at a premium.

I argue that considerations about computational complexity show that all finite agents need characteristics like those that have been called epistemic virtues. The necessity of these virtues follows in part from the nonexistence of shortcuts, or efficient ways of finding shortcuts, to cognitively expensive routines. It follows that agents must possess the capacities – metavirtues –of developing in advance the cognitive virtues they will need when time and memory are at a premium.

This paper considers two novel Bayesian responses to a well-known skeptical paradox. The paradox consists of three intuitions: first, given appropriate sense experience, we have justification for accepting the relevant proposition about the external world; second, we have justification for expanding the body of accepted propositions through known entailment; third, we do not have justification for accepting that we are not disembodied souls in an immaterial world deceived by an evil demon. The first response we consider rejects the third intuition (...) and proposes an explanation of why we have a faulty intuition. The second response, which we favor, accommodates all three intuitions; it reconciles the first and the third intuition by the dual component model of justification, and defends the second intuition by distinguishing two principles of epistemic closure. (shrink)

Recent work has argued that belief is weak: the level of rational credence required for belief is relatively low. That literature has contrasted belief with assertion, arguing that the latter requires an epistemic state much stronger than (weak) belief---perhaps knowledge or even certainty. We argue that this is wrong: assertion is just as weak as belief. We first present a variety of new arguments for this, and then show that the standard arguments for stronger norms are not convincing. Finally, we (...) sketch an alternative picture on which the fundamental norm of assertion is to say what you believe, but both belief and assertion are weak. To help make sense of this, we propose that both belief and assertion involve navigating a tradeoff between accuracy and informativity, and so it can makes sense to believe/say something you only have weak evidence for, if it is informative enough. (shrink)