There is an apparent conflict in Quine’s work between, on the one hand, his clear commitment to the rational revisability of logic and, on the other, his principle of charitable translation and ‘change of logic, change of subject’ argument. I argue that the apparent conflict is mostly resolved under close exegesis, but that the translation argument normatively rules out collaborative revision and allows only revision by individuals. However, I articulate a Neo-Quinean view that preserves the rational acceptability (...) of collaborative revision. On that view, everything is rationally revisable in some manner or other — it’s just that the logical principles that laypersons find (actually or potentially) obvious and tacitly use to govern their everyday inferences can’t be rationally revised quickly and all at once. Since, in Quine’s view, what most people find obvious resists change, rational changes to laymen’s logic must be gradual. (shrink)

We introduce a new operator, called rational evaluation, in belief change. The operator evaluates new information according to the agent’s core beliefs, and then exports the plausible part of the new information. It belongs to the decision module in belief change. We characterize rational evaluation by axiomatic postulates and propose two functional constructions for it, based on the well-known constructions of kernel sets and remainder sets, respectively. The main results of the paper are two representation theorems with respect (...) to the two functional constructions. We also compare and connect the evaluation operator with some related operators in belief revision, including contraction, set contraction, and prioritized multiple revision. (shrink)

Habermas's early work on action and practical rationality -- Practical rationality in Habermas's communicative paradigm -- Towards a thoroughly communicative conception of social action and its rationality.

To the normal reasons that we think can justify one in preferring something, x (namely, that x has objectively preferable properties, or has properties that one prefers things to have, or that x's obtaining would advance one's preferences), I argue that it can be a justifying reason to prefer x that one's very preferring of x would advance one's preferences. Here, one prefers x not because of the properties of x, but because of the properties of one's having the preference (...) for x. So-revising one's preferences is rational in paradoxical choice situations like Kavka's Deterrence Paradox. I then try to meet the following objections: that this is stoicist, incoherent, bad faith; that it conflates instrumental and intrinsic value, gives wrong solutions to the problems presented by paradoxical choice situations, entails vicious regresses of value justification, falsifies value realism, makes valuing x unresponsive to x's properties, causes value conflict, conflicts with other standards of rationality, violates decision theory, counsels immorality, makes moral paradox, treats value change as voluntary, conflates first- and second-order values, is psychologically unrealistic, and wrongly presumes that paradoxical choice situations can even occur. (shrink)

When an agent can not recognize, immediately, the implausible part of new information received, she will usually first expand her belief state by the new information, and then she may encounter some belief conflicts, and find the implausible information based on her criteria to consolidate her belief state. This process indicates a new kind of non-prioritized multiple revision, called metabolic revision. I give some axiomatic postulates for metabolic revision and propose two functional constructions for it, namely kernel metabolic revision and (...) partial meet metabolic revision, with respect to which the representation theorems are proved. I also compare metabolic revision with some related works in the literature, including semi-revision, merging with integrity constraints, evaluation, and evaluative multiple revision. (shrink)

We are fallible creatures, prone to making all sorts of mistakes. So, we should be open to evidence of error. But what constitutes such evidence? And what is it to rationally accommodate it? I approach these questions by considering an evolutionary debunking argument according to which (a) we have good, scientific, reason to think our moral beliefs are mistaken, and (b) rationally accommodating this requires revising our confidence in, or altogether abandoning the suspect beliefs. I present a dilemma for such (...) debunkers, which shows that either we have no reason to worry about our moral beliefs, or we do but we can self-correct. Either way, moral skepticism doesn’t follow. That the evolutionary debunking argument fails is important; also important, however, is what its failure reveals about rational belief revision. Specifically, it suggests that getting evidence of error is a non-trivial endeavor and that we cannot learn that we are likely to be mistaken about some matter from a neutral stance on that matter. (shrink)

Gupta has proposed a definition of strategic rationality cast in the framework of his revision theory of truth. His analysis, relative to a class of normal form games in which all players have a strict best reply to all other players’ strategy profiles, shows that game-theoretic concepts have revision-theoretic counterparts. We extend Gupta’s approach to deal with normal form games in which players’ may have weak best replies. We do so by adapting intuitions relative to Nash equilibrium refinements to the (...) revision-theoretic framework. We prove that there is a precise equivalence between trembling-hand perfect equilibria in two-player normal games and a revision-theoretic property. We then introduce lexicographic choice of action as a way to represent players’ expectations, which allows our analysis to reach full generality. Finally, we provide an example of the versatility of revision theory as applied to strategic interaction by formalizing a risk-and-compensation procedure of strategic choice in the revision-theoretic framework. (shrink)

We establish a correspondence between the rationalizability of choice studied in the revealed preference literature and the notion of minimal belief revision captured by the AGM postulates. A choice frame consists of a set of alternatives , a collection E of subsets of (representing possible choice sets) and a function f : E ! 2 (representing choices made). A choice frame is rationalizable if there exists a total pre-order R on..

The topic of this study is to what extent standards of rational inquiry can be rationally criticized and revised. It is argued that it is rational to treat all such standards as open to criticism and revision. Arguments to the effect that we are fallible with regard to all standards of rational inquiry are presented. Standards cannot be ultimately justified and with certainty established either as adequate or as inescapable presuppositions. Apel's attempt to give ultimate justifications of (...) certain moral and logical rules is examined and criticized. Special attention is given to our fallibility with regard to logical inference rules. The idea that certain logical rules cannot be put into question because any critical argument presupposes them is criticized. It has been claimed that there must be some basic standards which are such that they cannot be rationally evaluated and hence are rationally unrevisable. This is called "the unrevisability thesis". Related to this thesis is the normative policy according to which rationality requires that some standards be treated as unrevisable, the unrevisability policy. Two arguments that have been used to defend the unrevisability thesis and policy are examined and criticized. The conclusion is that we are not forced to accept either the thesis or the policy. The negation of the unrevisability policy is the revisability policy, according to which it is rational to treat all standards as open to rational criticism and revision. Objections that have been directed against the revisability policy are discussed and criticized. According to the objections, the revisability policy leads to rationality relativism. These objections are refuted, and it is argued that it is, on the contrary, rational to adopt the revisability policy and treat all standards of rational inquiry as criticizable and revisable. It is proposed that the rational change of standards should be viewed as a bootstrap process. General features of a bootstrap view of rational change of standards are presented, and it is argued that it is impossible to formulate a real theory of bootstrapping. Two models of standard change are presented and discussed: Laudan's reticulated model of scientific rationality and Briskman's bootstrap theory. It is claimed that in spite of defects and limitations, these models contribute to a richer understanding of bootstrapping. The fallibility and revisability of standards of rational inquiry have consequences for how the normativity of rationality should be understood. The book ends with an account of how the rationality of cognitive actions is related to the idea of the adequacy of standards. A distinction between absolute and standard-relative rationality is made, and it is argued that what an inquiring agent rationally ought to do coincides with what it is standard-relatively rational for him to do. It is shown that this view of rationality of inquiry is nevertheless inconsistent with rationality relativism, and that it is compatible with an objectivistic view of rationality. (shrink)

1. There is no dearth of objections to Rawls's A Theory of justice. Scores of articles and several books begin by praising the rigor and depth of Rawls's book — and end by concluding that it is thoroughly mistaken. In the present essay I will not add to the list of negative responses to A Theory of Justice. Instead I will attempt to reply to Rawls's critics in a way which makes a positive contribution to his theory.2. Among the many (...) objections that have been raised against Rawls's theory, two are of paramount importance. It is these two objections I shall attempt to meet. They may be formulated as follows. (shrink)

Sarah Waller proposes that cognitive therapists and philosophical counselors ought to consider the feelings of the client of paramount importance in belief system change rather than the rationality of the belief system. I offer an alternative strategy of counseling that reinstates the place of rational belief revision while still respecting the importance of emotions. Waller claims that, because of the problem of under-determination, the counseling goal of rational belief revision can be trumped by the goal of improved client (...) affect. I suggest that, if we consider a different ontology for the domain of counseling - one whose objects are dialogues (the goal of counseling becomes greater information of dialogues), we can accommodate a place for emotions in rational belief revision. I then note some limitations of the new proposal and the possibility of incommensurability in the comparison of our different views. (shrink)

Hans Rott has argued, most recently in his book Change, Choice and Inference, that certain formal correspondences between belief revision and rational choice have important philosophical implications, claiming that the former strongly indicate the unity of practical and theoretical reason as well as the primacy of practical reason. In this paper, I confront Rott's argument with three serious challenges. My conclusion is that, while Rott's work is indisputable as a formal achievement, the philosophical consequences he wants to draw are (...) not forthcoming. (shrink)

Hans Rott has argued, most recently in his book Change, Choice and Inference, that certain formal correspondences between belief revision and rational choice have important philosophical implications, claiming that the former strongly indicate the unity of practical and theoretical reason as well as the primacy of practical reason. In this paper, I confront Rott's argument with three serious challenges. My conclusion is that, while Rott's work is indisputable as a formal achievement, the philosophical consequences he wants to draw are (...) not forthcoming. (shrink)

The rational choice paradigm has proved to be a fruitful means of analysis and explanation in various disciplines concerned with questions of practical rationality, but in various attempts to extend its fields of application the deficiencies of the original account of rational choice have become evident. This paper tries to give a systematic overview of ways in which the rational choice paradigm can be extended and modified.

Imre Lakatos’ idea that history of science without philosophy of science is blind may still be given a plausible interpretation today, even though his theory of the methodology of scientific research programmes has been rejected. The latter theory captures neither rationality in science nor the sense in which history must be told in a rational fashion. Nonetheless, Lakatos was right in insisting that the discipline of history consists of written rational reconstructions. In this paper, we will examine possible (...) ways to cash out different, philosophically interesting, relationships: between rationality and science, between rationality and philosophy of science and/or epistemology, and, of course, between history and philosophy of science. Our conclusion is that the historian of science may be a philosopher of science as weIl, but if that philosophy of science is essentially a historical and dogmatic, it either cannot be used for history or it will deprive history of some of its most interesting and useful categories. (shrink)

An account of how a rational agent should revise beliefs in the light of new evidence.

This collection of essays is on the relation between probabilities, especially conditional probabilities, and conditionals. It provides negative results which sharply limit the ways conditionals can be related to conditional probabilities. There are also positive ideas and results which will open up areas of research. The collection is intended to honour Ernest W. Adams, whose seminal work is largely responsible for creating this area of inquiry. As well as describing, evaluating, and applying Adams's work the contributions extend his ideas in (...) directions he may or may not have anticipated, but that he certainly inspired. In addition to a wide range of philosophers of science, the volume should interest computer scientists and linguists. (shrink)

This book represents a major contribution to game theory. It offers this conception of equilibrium in games: strategic equilibrium. This conception arises from a study of expected utility decision principles, which must be revised to take account of the evidence a choice provides concerning its outcome. The argument for these principles distinguishes reasons for action from incentives, and draws on contemporary analyses of counterfactual conditionals. The book also includes a procedure for identifying strategic equilibria in ideal normal-form games. In synthesizing (...) decision theory and game theory in a powerful way this book will be of particular interest to all philosophers concerned with decision theory and game theory as well as economists and other social scientists. (shrink)

RÉSUMÉ: Une «situation de choix paradoxal» est une situation dans laquelle un agent connaîtrait davantage de succès en regard des préférences qu’il a effectivement, si ces préférences étaient différentes de ce qu’elles sont. Supposons que les agents rationnels ne choisissent pas à l’encontre de leurs préférences, que leur choix n’est déterminé que par ces préférences, et que leurs préférences intrinsèques ne changent pas de façon spontanée, automatique et directe sous l’influence de la critique rationnelle. Même dans de telles hypothèses, les (...) agents rationnels peuvent résoudre optimalement un éventail de situations de choix paradoxal au moyen de mécanismes qui les amènent à réviser leurs préférences. Dans cet article, je présente et défends un tel modèle de révision rationnelle des préférences. (shrink)

Like many theorists before him, Paul Weirich has set out to find the Holy Grail of classical game theory: the solution concept that identifies the uniquely rational solution to every non-cooperative game. In this book, he reports an intermediate stage in his quest. He cannot actually identify the unique solution for every game but, he believes, he has found a new concept of equilibrium that is a necessary property of that solution.

Although the AGM theory established a paradigm for the theory of belief revision, which is generally regarded as a kind of standard in the field, it is also frequently criticized as inadequate because it neglects justificational structures. Other theories of belief revision are similarly remiss in this regard. So far, little has been done to address this shortcoming. This paper aims to fill this gap. Following a critical analysis of the AGM theory, a justification operator is introduced as a formal (...) means to incorporate justificational structures into a belief revision theory. An AGM style belief revision theory is proposed that is based on such a justification operator. The theory is presented in an axiomatic form. Representation theorems link the axioms with constructive belief change mechanisms. The proposed theory addresses the problems of the AGM theory and similar approaches that neglect justificational structures. (shrink)

NOTE: this is a substantial revision of a previously uploaded draft. Intuitions are often thought of as inputs to theoretical reasoning. For example, you might form a belief by taking an intuition at face value, or you might take your intuitions as starting points in the method of reflective equilibrium. The aim of this paper is to argue that in addition to these roles intuitions also play action-guiding roles. The argument proceeds by reflection on the transmission of justification through inference. (...) According to inferential internalists, in order to gain justification for believing the conclusion of an argument by inferring it from the premises in that argument one must “see” that the premises support the conclusion. I motivate this view and endorse the idea that one’s “seeing” such a support relation consists of one’s having an intuition. In a number of recent papers, Paul Boghossian has pressed a regress argument against inferential internalism inspired by Lewis Carroll’s dialogue “What the Tortoise Said to Achilles.” I develop a response to Bogossian’s argument according to which intuitions work like mental imperatives and inferences are mental actions performed by obeying them. After developing this response to Boghossian’s argument, I take up the question of what it is in virtue of which intuitions play a guidance role, when they do so. (shrink)

This work contrasts conservative or minimally mutilating revisions of empirical theories as they are identified in the presently dominant AGM model of formal belief revision and the structuralist program for the reconstruction of empirical theories. The aim is to make understandable why both approaches only partly succeed in substantially informing and formally restraining the issue. With respect to the rationality of minimal change, the overall result is negative. Readers with an interest in formal epistemology are provided with application cases (mercury (...) anomaly, revision of early thermo-dynamics, introduction of the neutrino), the historically inclined reader is offered a systematic perspective. The discussion can largely be followed without a background in formal logic. (shrink)

According to an influential view that I call agentialism, our capacity to believe and intend directly on the basis of reasons—our rational agency—has a normative significance that distinguishes it from other kinds of agency (Bilgrami 2006, Boyle 2011, Burge 1996, Korsgaard 1996, Moran 2001). Agentialists maintain that insofar as we exercise rational agency, we bear a special kind of responsibility for our beliefs and intentions; and it is only those attitudes that represent the exercise of rational agency (...) that are truly our own. In this paper I challenge these agentialist claims. My argument centers on a case in which a thinker struggles to align her belief to her reasons, and succeeds only by resorting to non-rational methods. Because she relies on non-rational methods, this revision of her belief does not express her rational agency, in the agentialist sense. I argue that this process nevertheless expresses her capacities for rationality and agency; that she is responsible for the belief shaped through this process; and that the revised belief is truly her own. So rational agency is not distinctive in the ways that agentialists contend. (shrink)

This collection of essays is a Festschrift for Ernest W. Adams, and is based on a symposium that was held in his honor in 1993. As the title suggests, most of the essays focus on probability and the logic of conditionals, and the relationship between them; they draw their inspiration from Adams’s seminal work on the subject. As a computer scientist, I was struck by just how much the topics discussed play a major role in much recent work in computer (...) science, and how relevant much recent work in computer science is to some of the issues discussed here. (shrink)

This collection of essays is a Festschrift for Ernest W. Adams, and is based on a symposium that was held in his honor in 1993. As the title suggests, most of the essays focus on probability and the logic of conditionals, and the relationship between them; they draw their inspiration from Adams’s seminal work on the subject. As a computer scientist, I was struck by just how much the topics discussed play a major role in much recent work in computer (...) science, and how relevant much recent work in computer science is to some of the issues discussed here. (shrink)

We respond to recent comments on our proposal to improve justice in ventilator triage, in which we used as an example New Jersey’s publicly available and legally binding Directive Number 2020-03. We agree with Bernard Lo and Doug White that equity implications of triage frameworks should be continually reassessed, which is why we offered six concrete options for improvement, and called for monitoring the consequences of adopted triage models. We disagree with their assessment that we mis-characterised their Model Guidance, as (...) included in the NJ Directive, in ways that undermine our conclusions. They suggest we erroneously described their model as a two-criterion allocation framework; that recognising other operant criterion reveals it ‘likely mitigate[s] rather than exacerbate[s] racial disparities during triage’, and allege that concerns about inequitable outcomes are ‘without evidence’. We highlight two major studies robustly demonstrating why concerns about disparate outcomes are justified. We also show that White and Lo seek to retrospectively—and counterfactually—correct the version of the Model Guideline included in the NJ Directive. However, as our facsimile reproductions show, neither the alleged four-criteria form, nor other key changes, such as dropping the Sequential Organ Failure Assessment score, are found in the Directive. These points matter because our conclusions hence stand, because the public version of the Model Guidance had not been updated to reduce the risk of inequitable outcomes until June 2021 and NJ’s Directive still does not reflect these revisions, and, hence, represents a less equitable version, as acknowledged by its authors. We comment on broader policy implications and call for ways of ensuring accurate, transparent and timely updates for users of high-stakes guidelines. (shrink)

This is a survey paper. Contents: 1 Introduction -- 2 The representation of belief -- 3 Kinds of belief change -- 4 Coherence constraints for belief revision -- 5 Different modes of belief change -- 6 Two strategies for characterizing rational changes of belief - 6.1 The postulates strategy - 6.2 The constructive strategy -- 7 An abstract view of the elements of belief change -- 8 Iterated changes of belief -- 9 Further developments - 9.1 Variants and extensions (...) of belief revision - 9.2 Updates - 9.3 Default inferences as expectation revision - 9.4 Belief merging -- 10 Concluding remarks. (shrink)

This book represents a major contribution to game theory. It offers this conception of equilibrium in games: strategic equilibrium. This conception arises from a study of expected utility decision principles, which must be revised to take account of the evidence a choice provides concerning its outcome. The argument for these principles distinguishes reasons for action from incentives, and draws on contemporary analyses of counterfactual conditionals. The book also includes a procedure for identifying strategic equilibria in ideal normal-form games. In synthesizing (...) decision theory and game theory in a powerful way this book will be of particular interest to all philosophers concerned with decision theory and game theory as well as economists and other social scientists. (shrink)

The Bayesian maxim for rational learning could be described as conservative change from one probabilistic belief or credence function to another in response to newinformation. Roughly: ‘Hold fixed any credences that are not directly affected by the learning experience.’ This is precisely articulated for the case when we learn that some proposition that we had previously entertained is indeed true (the rule of conditionalisation). But can this conservative-change maxim be extended to revising one’s credences in response to entertaining propositions (...) or concepts of which one was previously unaware? The economists Karni and Vierø (2013, 2015) make a proposal in this spirit. Philosophers have adopted effectively the same rule: revision in response to growing awareness should not affect the relative probabilities of propositions in one’s ‘old’ epistemic state. The rule is compelling, but only under the assumptions that its advocates introduce. It is not a general requirement of rationality, or so we argue. We provide informal counterexamples. And we show that, when awareness grows, the boundary between one’s ‘old’ and ‘new’ epistemic commitments is blurred. Accordingly, there is no general notion of conservative change in this setting. (shrink)

Economic research is often isolated from social and political deliberations. Politicians put distinct results together in ad hoc ways. This state of affairs is explained as a result of equating rationality with coherence, system, and justification; the rationality principle, according to which social facts are to be explained as the result of coherent and/or justified plans of individuals, is singled out as the prime source of the isolation. A revised version is proposed which dispenses with the need for justification and/or (...) coherence for rational action of individuals. Partially rational actions are attempts to solve problems within given institutional contexts; individual rationality is a social activity whose value depends on the quality of social standards which individuals use to guide their thought. This revision removes barriers between economic, social, and political theories, without blocking social scientific explanation. Indeed, it opens up possibilities now blocked. (shrink)

This paper is the product of an interdisciplinary, interreligious dialogue aiming to outline some of the possibilities and rational limits of supernatural religious belief, in the light of a critique of David Hume’s familiar sceptical arguments -- including a rejection of his famous Maxim on miracles -- combined with a range of striking recent empirical research. The Humean nexus leads us to the formulation of a new ”Common-Core/Diversity Dilemma’, which suggests that the contradictions between different religious belief systems, in (...) conjunction with new understandings of the cognitive forces that shape their common features, persuasively challenge the rationality of most kinds of supernatural belief. In support of this conclusion, we survey empirical research concerning intercessory prayer, religious experience, near-death experience, and various cognitive biases. But we then go on to consider evidence that supernaturalism -- even when rationally unwarranted -- has significant beneficial individual and social effects, despite others that are far less desirable. This prompts the formulation of a ”Normal/Objective Dilemma’, identifying important trade-offs to be found in the choice between our humanly evolved ”normal’ outlook on the world, and one that is more rational and ”objective’. Can we retain the pragmatic benefits of supernatural belief while avoiding irrationality and intergroup conflict? It may well seem that rationality is incompatible with any wilful sacrifice of objectivity. But in a situation of uncertainty, an attractive compromise may be available by moving from the competing factions and mutual contradictions of ”first-order’ supernaturalism to a more abstract and tolerant ”second-order’ view, which itself can be given some distinctive intellectual support through the increasingly popular Fine Tuning Argument. We end by proposing a ”Maxim of the Moon’ to express the undogmatic spirit of this second-order religiosity, providing a cautionary metaphor to counter the pervasive bias endemic to the human condition, and offering a more cooperation- and humility-enhancing understanding of religious diversity in a tense and precarious globalised age. (shrink)

Since the early 1980s, logical theories of belief revision have offered formal methods for the transformation of knowledge bases or “corpora” of data and beliefs. Early models have dealt with unconditional acceptance and integration of potentially belief-contravening pieces of information into the existing corpus. More recently, models of “non-prioritized” revision were proposed that allow the agent rationally to refuse to accept the new information. This paper introduces a refined method for changing beliefs by specifying constraints on the relative plausibility of (...) propositions. Like the earlier belief revision models, the method proposed is a qualitative one, in the sense that no numbers are needed in order to specify the posterior plausibility of the new information. We use reference beliefs in order to determine the degree of entrenchment of the newly accepted piece of information. We provide two kinds of semantics for this idea, give a logical characterization of the new model, study its relation with other operations of belief revision and contraction, and discuss its intuitive strengths and weaknesses. (shrink)

The positivists suggest that some truths may be immune from empirical refutation and yet lacking in rational justification. Quine holds that every proposition is in principle empirically refutable so there are no a priori truths. I’ll provide a working characterization of the idea of “rational revisability” and argue it’s impossible for us to take a chain of rational revision and end up revising everything which we now believe. Quine's position on revisability is also in tension (...) with certain theses about epistemic holism. Finally, I discuss a more general context in which rational argument is viewed as one mechanism among many for reliably modifying beliefs. This more biological perspective allows us to formulate Quine's claims about revisability in a new way and to raise some interesting questions about the potential impact of natural selection on our cognitive capacities. (shrink)

While growing empirical evidence suggests a continuity between human and non-human psychology, many philosophers still think that only humans can act and form beliefs rationally. In this paper, we challenge this claim. We first clarify the notion of rationality. We then focus on the rationality of beliefs and argue that, in the relevant sense, humans are not the only rational animals. We do so by first distinguishing between unreflective and reflective responsiveness to epistemic reasons in belief formation and revision. (...) We argue that unreflective responsiveness is clearly within the reach of many animals. We then defend that a key demonstration of reflective responsiveness would be the ability to respond to undermining defeaters. We end by presenting some empirical evidence that suggests that some animal species are capable of processing these defeaters, which would entail that even by the strictest standards, humans are not the only rational animals. (shrink)

The rational status of the Bayesian calculus for revising likelihoods is compromised by the common but still unfamiliar phenomenon of information distortion. This bias is the distortion in the evaluation of a new datum toward favoring the currently preferred option in a decision or judgment. While the Bayesian calculus requires the independent combination of the prior probability and a new datum, information distortion invalidates such independence (because the prior influences the datum). Although widespread, information distortion has not generally been (...) recognized. First, individuals are not aware when they themselves commit this bias. In addition, it is often hidden in more obvious suboptimal phenomena. Finally, the Bayesian calculus is usually explained only with undistortable data like colored balls drawn randomly. Partly because information distortion is unrecognized by the individuals exhibiting it, no way has been devised for eliminating it. Partial reduction is possible in some situation such as presenting all data simultaneously rather than sequentially with revision after each datum. The potential dangers of information distortion are illustrated for three professional revision tasks: forecasting, predicting consumer choices from internet data, and statistical inference from experimental results. The optimality of the Bayesian calculus competes with people’s natural desire that their belief systems remain coherent in the face of new data. Information distortion provides this coherence by biasing those data toward greater agreement with the currently preferred position – but at the cost of Bayesian optimality. (shrink)

Choice revision is a sort of non-prioritized multiple revision, in which the agent partially accepts the new information represented by a set of sentences. We investigate the construction of choice revision based on a new approach to belief change called descriptor revision. We prove that each of two variants of choice revision based on such construction is axiomatically characterized with a set of plausible postulates, assuming that the object language is finite. Furthermore, we introduce an alternative modelling for choice revision, (...) which is based on a type of relation on sets of sentences, named multiple believability relation. We show without assuming a finite language that choice revision constructed from such relations is axiomatically characterized with the same sets of postulates that we proposed for the choice revision based on descriptor revision, whenever the relations satisfy certain rationality conditions. (shrink)