Belief Revision and Verisimilitude Based on Preference and Truth Orderings

In this rather technical paper we establish a useful combination of belief revision and verisimilitude according to which better theories provide better predictions, and revising with more verisimilar data results in theories that are closer to the truth. Moreover, this paper presents two alternative definitions of refined verisimilitude, which are more perspicuous than the algebraic version used in previous publications.     

Verisimilitude and Belief Change for Conjunctive Theories

Theory change is a central concern in contemporary epistemology and philosophy of science. In this paper, we investigate the relationships between two ongoing research programs providing formal treatments of theory change: the (post-Popperian) approach to verisimilitude and the AGM theory of belief change. We show that appropriately construed accounts emerging from those two lines of epistemological research do yield convergences relative to a specified kind of theories, here labeled “conjunctive”. In this domain, a set of plausible conditions are identified which demonstrably capture the verisimilitudinarian effectiveness of AGM belief change, i.e., its effectiveness in tracking truth approximation. We conclude by indicating some further developments and open issues arising from our results.     

Symmetry and Belief Revision

This paper continues the recent tradition of investigating iterated AGM revision by reasoning directly about the dynamics for total pre-order (“implausibility ordering”) representations of AGM revision functions. We reorient discussion, however, by proving that symmetry considerations, almost by themselves, suffice to determine a particular, AGM-friendly implausibility ordering dynamics due to Spohn 1988, which we call “J-revision”. After exploring the connections between implausibility ordering dynamics and the social choice theory of Arrow 1963, we provide symmetry arguments in the social choice-theoretic framework for an interesting generalization of J-revision due to Nayak 1994. We conclude by arguing that the symmetry principles that uniquely favor J-revision and its generalizations are importantly expressive of the purely qualitative framework for representing beliefs that distinguishes the AGM program. Our results therefore comprehensively vindicate Spohn's 1988 conjecture that essentially J-revision is the best that can be done by way of a purely qualitative model of belief revision. This revised version was published online in August 2006 with corrections to the Cover Date.     

The Paradox of Belief Instability and a Revision Theory of Belief

The epistemic paradox of 'belief instability' has recently received notable attention from many philosophers. In this paper I offer a new proposal, which I call a 'revision theory of belief'. This theory is in many respects an application of Gupta's and Belnap's revision theory of truth. They argue that the Liar paradox arises because our notion of truth is circular. I offer a similar proposal for handling the paradox of belief instability. In particular, I argue that our notion involved in the paradox of belief instability is circular, and this circularity of belief is the source of the paradox.     

Iterated Belief Revision and Conditional Logic

In this paper we propose a conditional logic called IBC to represent iterated belief revision systems. We propose a set of postulates for iterated revision which are a small variant of Darwiche and Pearl's ones. The conditional logic IBC has a standard semantics in terms of selection function models and provides a natural representation of epistemic states. We establish a correspondence between iterated belief revision systems and IBC-models. Our representation theorem does not entail Gärdenfors' Triviality Result.     

Interrogative Belief Revision Based on Epistemic Strategies

I develop a dynamic logic for reasoning about ??interrogative belief revision??, a new branch of belief revision theory that has been developed in a small number of papers, beginning with E. J. Olsson and D. Westlund??s paper ??On the role of the research agenda in epistemic change?? [12]. In interrogative belief revision, epistemic states are taken to include a research agenda, consisting of questions the agent seeks to answer. I present a logic for revision of such epistemic states based on the notion of an epistemic strategy, a stable plan of action that determines changes in the agent??s research agenda. This idea is a further development of an idea put forward in [6], that changes in the research agenda of an agent should be determined by stable, ??long term?? research interests. I provide complete axioms and a decidability result for the logic.     

逻辑心理主义：一种信念修正的视角

以穆勒为代表的逻辑心理主义与以弗雷格为代表的反心理主义之间的争论由来已久。逻辑心理主义认为,逻辑是心理学的一部分或是其分支,具有描述性;反心理主义则认为,应当把心理的东西从逻辑中剔除,逻辑只是规范性的。信念修正理论虽具有规范性特质,但是当信念状态层级从低层级走向高层级时,其规范性解释力度则会降低,这表明信念状态的改变会受到经验描述的影响,信念修正理论研究有从规范性走向描述性的层级区分。信念修正理论一定程度上能为弱逻辑心理主义在逻辑中的合法性提供支持,并将心理主义与反心理主义聚焦在人即主体上。     

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”     

Bounded Revision: Two-Dimensional Belief Change Between Conservative and Moderate Revision

This paper presents the model of ‘bounded revision’ that is based on two-dimensional revision functions taking as arguments pairs consisting of an input sentence and a reference sentence. The key idea is that the input sentence is accepted as far as (and just a little further than) the reference sentence is ‘cotenable’ with it. Bounded revision satisfies the AGM axioms as well as the Same Beliefs Condition (SBC) saying that the set of beliefs accepted after the revision does not depend on the reference sentence (although the posterior belief state does depend on it). Bounded revision satisfies the Darwiche–Pearl (DP) axioms for iterated belief change. If the reference sentence is fixed to be a tautology or a contradiction, two well-known one-dimensional revision operations result. Bounded revision thus naturally fills the space between conservative revision (also known as natural revision) and moderate revision (also known as lexicographic revision). I compare this approach to the two-dimensional model of ‘revision by comparison’ investigated by Fermé and Rott (Artif Intell 157:5–47, 2004) that satisfies neither the SBC nor the DP axioms. I conclude that two-dimensional revision operations add substantially to the expressive power of qualitative approaches that do not make use of numbers as measures of degrees of belief.     

Data-Driven Belief Revision in Children and Adults

The ability to use numerical evidence to revise beliefs about the physical world is an essential component of scientific reasoning that begins to develop in middle childhood. In 2 studies, we explored how data variability and consistency with participants’ initial beliefs about causal factors associated with pendulums affected their ability to revise those beliefs. Children (9–11 years old) and college-aged adults ran experiments in which they generated, recorded, and interpreted data so as to identify factors that might affect the period of a pendulum. In Study 1, several children and most adults used observed evidence to revise their initial understanding, but participants were more likely to change incorrect noncausal beliefs to causal beliefs than the reverse. In Study 2, we oriented participants toward either an “engineering” goal (to get an effect) or a “science” goal (to discover the causal structure of the domain) and presented them with variable data about potentially causal factors. Science goals produced more belief revision than engineering goals. Numerical data, when presented in context, with appropriate structure, can help children and adults reexamine their beliefs and initiate and support the process of conceptual change and robust scientific thinking.     

Scientific Discovery on Positive Data via Belief Revision

A model of inductive inquiry is defined within a first-order context. Intuitively, the model pictures inquiry as a game between Nature and a scientist. To begin the game, a nonlogical vocabulary is agreed upon by the two players along with a partition of a class of structures for that vocabulary. Next, Nature secretly chooses one structure (the real world) from some cell of the partition. She then presents the scientist with a sequence of atomic facts about the chosen structure. With each new datum the scientist announces a guess about the cell to which the chosen structure belongs. To succeed in his inquiry, the scientist's successive conjectures must be correct all but finitely often, that is, the conjectures must converge in the limit to the correct cell. A special kind of scientist selects his hypotheses on the basis of a belief revision operator. We show that reliance on belief revision allows scientists to solve a wide class of problems.     

Belief Revision,Rational Choice and the Unity of Reason

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. This revised version was published online in August 2006 with corrections to the Cover Date.     

Iterated Belief Revision, Reliability, and Inductive Amnesia

Belief revision theory concerns methods for reformulating an agent's epistemic state when the agent's beliefs are refuted by new information. The usual guiding principle in the design of such methods is to preserve as much of the agent's epistemic state as possible when the state is revised. Learning theoretic research focuses, instead, on a learning method's reliability or ability to converge to true, informative beliefs over a wide range of possible environments. This paper bridges the two perspectives by assessing the reliability of several proposed belief revision operators. Stringent conceptions of minimal change are shown to occasion a limitation called inductive amnesia: they can predict the future only if they cannot remember the past. Avoidance of inductive amnesia can therefore function as a plausible and hitherto unrecognized constraint on the design of belief revision operators.     

The Stability Theory of Knowledge and Belief Revision: Comments on Rott

In this commentary on Rotts paper Stability, Strength and Sensitivity: Converting Belief into Knowledge, I discuss two problems of the stability theory of knowledge which are pointed out by Rott. I conclude that these problems offer no reason for rejecting the stability theory, but might be grounds for deviating from the standard AGM account of belief revision which Rott presupposes.     

Truth in Fiction,Impossible Worlds,and Belief Revision

We present a theory of truth in fiction that improves on Lewis's [1978] ‘Analysis 2’ in two ways. First, we expand Lewis's possible worlds apparatus by adding non-normal or impossible worlds. Second, we model truth in fiction as (make-believed) belief revision via ideas from dynamic epistemic logic. We explain the major objections raised against Lewis's original view and show that our theory overcomes them.     

Belief Change in Branching Time: AGM-consistency and Iterated Revision

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.     

Verisimilitude and the Dynamicsof Scientific Research Programmes

Some peculiarities of the evaluation of theories within scientific research programmes (SRPs) and of the assessing of rival SRPs are described assuming that scientists try to maximise an ‘epistemic utility function’ under economic and institutional constraints. Special attention is given to Lakatos' concepts of ‘empirical progress’ and ‘theoretical progress’. A notion of ‘empirical verisimilitude’ is defended as an appropriate utility function. The neologism ‘methodonomics’ is applied to this kind of studies. This revised version was published online in August 2006 with corrections to the Cover Date.     

Velocity as a Predictor of Performance Satisfaction,Mental Focus,and Goal Revision

In a longitudinal study, the authors examined the role of students' rate of progress, or velocity, in goal‐striving over one semester of a college‐level Introductory Psychology course. At both mid‐course and near end‐of‐course time periods, results demonstrated that velocity uniquely contributed to the prediction of students' performance satisfaction, mental focus, and goal revision, above and beyond the influence of performance‐goal discrepancies and ability. Specifically, velocity demonstrated main effects on performance satisfaction and mental focus. Velocity significantly interacted with goal importance in the prediction of goal revision. The authors call for increased attention to the role of velocity in self‐regulation. Dans une étude longitudinale, les auteurs examinent le rôle du taux de progrès des étudiants ou leur rapiditéà atteindre des buts sur un semestre pour un cours d'introduction à la psychologie en faculté. Deux mesures ont été faites: l'une à la moitié du semestre et l'autre à la fin de ce même semestre. Les résultats montrent que uniquement la rapidité contribue à prédire la satisfaction de la performance des étudiants, la concentration, et la révision de l'objectif quels que soient les écarts entre le but de la performance et les capacités. Plus spécifiquement, la rapidité a des effets importants sur la satisfaction de la performance et la concentration. La rapidité interagit significativement avec l'importance des buts dans le cas où l'on envisage leur révision. Les auteurs soulignent le rôle de la rapidité sur l'auto‐régulation.     

文昌信仰的神谕性训诫研究——以文昌劝善书为中心

劝善书产生于北宋时期,是一种宣传伦理道德、劝诫世人行善去恶并建立道德规范的指导书.文昌信仰是由产生于远古的星宿信仰、晋朝武将张恶子信仰等合流的一种民间信仰.文昌劝善书是以文昌信仰为基础所造做的劝善书,成为明清时期劝善书的主流.本文主要以一些明清时期重要文昌劝善书为例,探讨文昌神谕性的训诫及其对社会的影响.