Against Probabilistic Measures of Coherence

It is shown that the probabilistic theories of coherence proposed up to now produce a number of counter-intuitive results. The last section provides some reasons for believing that no probabilistic measure will ever be able to adequately capture coherence. First, there can be no function whose arguments are nothing but tuples of probabilities, and which assigns different values to pairs of propositions {A, B} and {A, C} if A implies both B and C, or their negations, and if P(B)=P(C). But such sets may indeed differ in their degree of coherence. Second, coherence is sensitive to explanatory relations between the propositions in question. Explanation, however, can hardly be captured solely in terms of probability.     

Problems with Priors in Probabilistic Measures of Coherence

Two of the probabilistic measures of coherence discussed in this paper take probabilistic dependence into account and so depend on prior probabilities in a fundamental way. An example is given which suggests that this prior-dependence can lead to potential problems. Another coherence measure is shown to be independent of prior probabilities in a clearly defined sense and consequently is able to avoid such problems. The issue of prior-dependence is linked to the fact that the first two measures can be understood as measures of coherence as striking agreement, while the third measure represents coherence as agreement. Thus, prior (in)dependence can be used to distinguish different conceptions of coherence.     

A General Framework for Probabilistic Measures of Coherence

Studia Logica - Coherence is a property of propositions hanging together or dovetailing with each other. About two decades ago, formal epistemologists started to engage in the project of...     

Coherence and Conservatism in the Dynamics of Belief

In this paper I discuss the foundations of a formal theory of coherent and conservative belief change that is (a) suitable to be used as a method for constructing iterated changes of belief, (b) sensitive to the history of earlier belief changes, and (c) independent of any form of dispositional coherence. I review various ways to conceive the relationship between the beliefs actually held by an agent and her belief change strategies (that also deal with potential belief sets), show the problems they suffer from, and suggest that belief states should be represented by unary revision functions that take sequences of inputs. Three concepts of coherence implicit in current theories of belief change are distinguished: synchronic, diachronic and dispositional coherence. Diachronic coherence is essentially identified with what is known as conservatism in epistemology. The present paper elaborates on the philosophical motivation of the general framework; formal details and results are provided in a companion paper.     

Disembodied Minds and the Problem of Identification and Individuation

We consider and reject a variety of attempts to provide a ground for identifying and differentiating disembodied minds. Until such a ground is provided, we must withhold inclusion of disembodied minds from our picture of the world.

Coherence in Epistemology and Belief Revision*

A general theory of coherence is proposed, in which systemic and relational coherence are shown to be interdefinable. When this theory is applied to sets of sentences, it turns out that logical closure obscures the distinctions that are needed for a meaningful analysis of coherence. It is concluded that references to “all beliefs” in coherentist phrases such as “all beliefs support each other” have to be modified so that merely derived beliefs are excluded. Therefore, in order to avoid absurd conclusions, coherentists have to accept a weak version of epistemic priority, that sorts out merely derived beliefs. Furthermore, it is shown that in belief revision theory, coherence cannot be adequately represented by logical closure, but has to be represented separately. *Contribution to “Seven Bridges”     

Probabilistic Justification and the Regress Problem

We discuss two objections that foundationalists have raised against infinite chains of probabilistic justification. We demonstrate that neither of the objections can be maintained. Presented by Hannes Leitgeb     

The Frame Problem and Theories of Belief

The frame problem is the problem of how we selectively apply relevant knowledge to particular situations in order to generate practical solutions. Some philosophers have thought that the frame problem can be used to rule out, or argue in favor of, a particular theory of belief states. But this is a mistake. Sentential theories of belief are no better or worse off with respect to the frame problem than are alternative theories of belief, most notably, the “map” theory of belief.     

Moore's Problem with Iterated Belief

G.E. Moore's problem is to explain what is odd about sentences such as 'It is raining but I do not believe it'. This sentence is unbelievable whether read commissively as ' p & B ^{˜/sup> p ', or omissively as ' p} & ^{˜/sup> B p '. However, this symmetry is broken when the belief operator is iterated many times. Whereas the commissive ' p & BBBBBBBBBB˜} p ' preserves the oddity Moore first noted, ' p & ^˜BBBBBBBBBB p ' is believable and assertable. The usual explanations of what is odd about Moore's sentences use recursive rules. Hence they uniformly extend the prediction of oddity when the belief operator is iterated. My project is to show how the asymmetry of the iterated version can be respected.     

Probabilistic Regresses and the Availability Problem for Infinitism

Recent work by Peijnenburg, Atkinson, and Herzberg suggests that infinitists who accept a probabilistic construal of justification can overcome significant challenges to their position by attending to mathematical treatments of infinite probabilistic regresses. In this essay, it is argued that care must be taken when assessing the significance of these formal results. Though valuable lessons can be drawn from these mathematical exercises (many of which are not disputed here), the essay argues that it is entirely unclear that the form of infinitism that results meets a basic requirement: namely, providing an account of infinite chains of propositions qua reasons made available to agents.     

Why There Cannot be a Single Probabilistic Measure of Coherence

Bayesian Coherence Theory of Justification or, for short, Bayesian Coherentism, is characterized by two theses, viz. (i) that our degree of confidence in the content of a set of propositions is positively affected by the coherence of the set, and (ii) that coherence can be characterized in probabilistic terms. There has been a longstanding question of how to construct a measure of coherence. We will show that Bayesian Coherentism cannot rest on a single measure of coherence, but requires a vector whose components exhaustively characterize the coherence properties of the set. Our degree of confidence in the content of the information set is a function of the reliability of the sources and the components of the coherence vector. The components of this coherence vector are weakly but not strongly separable, which blocks the construction of a single coherence measure.     

信仰问题研讨综述--全国社科院系统哲学所长会议侧记

全国社科院系统哲学所长会议于 2 0 0 2年 5月 10 -11日在石家庄河北省社会科学院召开。会议研讨的主题是“信仰和价值观在当代社会中的地位和作用”。与会代表关于信仰问题的讨论比较深入 ,在如下几个方面提出了一些新的观点。一、什么是信仰 ?一种观点认为 ,并非对任何事物的坚信态度都可以被称之为信仰 ,信仰与信念指的是对于某些尚未被实现和证实的客观状态或观念的确信。有的代表提出 ,信仰指的是对某些非实证的事物所固持的坚信不移的态度。希望一切信念都能得到经验和逻辑的支持 ,这是极端理性主义者的一种理想追求 ,实际上更普遍的…     

Probabilistic Logic Under Coherence, Conditional Interpretations, and Default Reasoning

We study a probabilistic logic based on the coherence principle of de Finetti and a related notion of generalized coherence (g-coherence). We examine probabilistic conditional knowledge bases associated with imprecise probability assessments defined on arbitrary families of conditional events. We introduce a notion of conditional interpretation defined directly in terms of precise probability assessments. We also examine a property of strong satisfiability which is related to the notion of toleration well known in default reasoning. In our framework we give more general definitions of the notions of probabilistic consistency and probabilistic entailment of Adams. We also recall a notion of strict p-consistency and some related results. Moreover, we give new proofs of some results obtained in probabilistic default reasoning. Finally, we examine the relationships between conditional probability rankings and the notions of g-coherence and g-coherent entailment.     

理解信仰问题的主要视角

信仰的问题十分复杂,基于不同的立场和视角完全可能对其给予不同的理解。本文即是对这些不同的视角做一个概略地考察,并在此基础上扼要分析考察信仰问题的若干维度。这些视角主要包括:基于宗教哲学的对信仰与理性的区别;基于人类学或社会学的广义的信仰概念;基于高端信仰的狭义信仰概念;基于亚伯拉罕宗教系统的一神信仰概念;基于宗教多元论的多元信仰概念;基于发展角度的考察:信仰可能由高端向低端的回归趋势。     

Low‐Involvement Learning: Repetition and Coherence in Familiarity and Belief

Over thirty years ago Krugman (1965) claimed that learning of advertising messages was much more like an Ebbinghaus nonsense syllable memory task than an exercise in rhetoric. If anything, he seems even more right today in a media environment that continues to become more cluttered. In this article, we investigate the role that memory plays in the development of beliefs within this context and focus on the formation of beliefs that develop with little intention or opportunity to learn. Following on previous work, we investigate the effect of repetition‐induced increases in belief for advertising claims that are hierarchically related: a superordinate general benefit claim (e.g., security of a lock) and multiple subordinate feature claims (e.g., pick resistant and professional installation required). We find that beliefs in feature claims increase monotonically with number of exposures, although at a diminishing marginal rate. We find no evidence of horizontal spillover of repetition‐induced increases in belief from one subordinate feature claim to another. However, we find a substantial amount of vertical spillover of repetition‐induced increases in belief from individual subordinate feature claims to the superordinate general benefit. A dual mediation analysis suggests that the vertical spillover comes from both an increase in familiarity of the general benefit and greater belief in the set of subordinate feature claims.     

Coverage-Reliability, Epistemic Dependence, and the Problem of Rumor-Based Belief

Rumors, for better or worse, are an important element of public discourse. The present paper focuses on rumors as an epistemic phenomenon rather than as a social or political problem. In particular, it investigates the relation between the mode of transmission and the reliability, if any, of rumors as a source of knowledge. It does so by comparing rumor with two forms of epistemic dependence that have recently received attention in the philosophical literature: our dependence on the testimony of others, and our dependence on what has been called the ‘coverage-reliability’ of our social environment (Goldberg 2010). According to the latter, an environment is ‘coverage-reliable’ if, across a wide range of beliefs and given certain conditions, it supports the following conditional: If ~p were true I would have heard about it by now. However, in information-deprived social environments with little coverage-reliability, rumors may transmit information that could not otherwise be had. This suggests that a trade-off exists between levels of trust in the coverage-reliability of official sources and (warranted) trust in rumor as a source of information.