A puzzle about epistemic akrasia

In this paper I will present a puzzle about epistemic akrasia, and I will use that puzzle to motivate accepting some non-standard views about the nature of epistemological judgment. The puzzle is that while it seems obvious that epistemic akrasia must be irrational, the claim that epistemic akrasia is always irrational amounts to the claim that a certain sort of justified false belief—a justified false belief about what one ought to believe—is impossible. But justified false beliefs seem to be possible in any domain, and it’s hard to see why beliefs about what one ought to believe should be an exception. I will argue that when we get clearer about what sort of psychological state epistemic akrasia is, we can resolve the puzzle in favor of the intuitive view that epistemic akrasia is always irrational.     

Bridging learning theory and dynamic epistemic logic

This paper discusses the possibility of modelling inductive inference (Gold 1967) in dynamic epistemic logic (see e.g. van Ditmarsch et al. 2007). The general purpose is to propose a semantic basis for designing a modal logic for learning in the limit. First, we analyze a variety of epistemological notions involved in identification in the limit and match it with traditional epistemic and doxastic logic approaches. Then, we provide a comparison of learning by erasing (Lange et al. 1996) and iterated epistemic update (Baltag and Moss 2004) as analyzed in dynamic epistemic logic. We show that finite identification can be modelled in dynamic epistemic logic, and that the elimination process of learning by erasing can be seen as iterated belief-revision modelled in dynamic doxastic logic. Finally, we propose viewing hypothesis spaces as temporal frames and discuss possible advantages of that perspective.     

Have a Cake and Eat it Too: Identifying a Missing Link in the Skeptical Puzzle

The skeptical puzzle consists of three allegedly incompatible claims: S knows that O, S doesn’t know that ~U, and the claim that knowledge is closed under the known entailment. I consider several famous instances of the puzzle and conclude that in all of those cases the presupposition that O entails ~U is false. I also consider two possible ways for trying to make it true and argue that both strategies ultimate fail. I conclude that this result at least completely discredits any solution that denies the principle of epistemic closure. At most, denying that O entails ~U can itself be seen as a novel solution to the puzzle, preferred to any other solution: it accommodates both non-skeptical and skeptical intuitions but does not require us to give up the principle of closure, embrace contextualism or subject-sensitive invariantism, or deny any commonly accepted principle of epistemology or logic.

     

A puzzle about epistemic value and steps towards a solution

Synthese - This paper exposits and makes steps towards solving a puzzle about epistemic value. The puzzle is that several principles about the epistemic value of true beliefs and epistemic disvalue...     

An Internal Version of Epistemic Logic

Representing an epistemic situation involving several agents obviously depends on the modeling point of view one takes. We start by identifying the types of modeling points of view which are logically possible. We call the one traditionally followed by epistemic logic the perfect external approach, because there the modeler is assumed to be an omniscient and external observer of the epistemic situation. In the rest of the paper we focus on what we call the internal approach, where the modeler is one of the agents involved in the situation. For this approach we propose and axiomatize a logical formalism based on epistemic logic. This leads us to formalize some intuitions about the internal approach and about its connections with the external ones. Finally, we show that our internal logic is decidable and PSPACE-complete.     

A nice surprise? Predictive processing and the active pursuit of novelty

Recent work in cognitive and computational neuroscience depicts human brains as devices that minimize prediction error signals: signals that encode the difference between actual and expected sensory stimulations. This raises a series of puzzles whose common theme concerns a potential misfit between this bedrock informationtheoretic vision and familiar facts about the attractions of the unexpected. We humans often seem to actively seek out surprising events, deliberately harvesting novel and exciting streams of sensory stimulation. Conversely, we often experience some wellexpected sensations as unpleasant and to-be-avoided. In this paper, I explore several core and variant forms of this puzzle, using them to display multiple interacting elements that together deliver a satisfying solution. That solution requires us to go beyond the discussion of simple information-theoretic imperatives (such as 'minimize long-term prediction error') and to recognize the essential role of species-specific prestructuring, epistemic foraging, and cultural practices in shaping the restless, curious, novelty-seeking human mind.     

Comparing Semantics of Logics for Multi-Agent Systems

We draw parallels between several closely related logics that combine — in different proportions — elements of game theory, computation tree logics, and epistemic logics to reason about agents and their abilities. These are: the coalition game logics CL and ECL introduced by Pauly 2000, the alternating-time temporal logic ATL developed by Alur, Henzinger and Kupferman between 1997 and 2002, and the alternating-time temporal epistemic logic ATEL by van der Hoek and Wooldridge (2002). In particular, we establish some subsumption and equivalence results for their semantics, as well as interpretation of the alternating-time temporal epistemic logic into ATL. The focus in this paper is on models: alternating transition systems, multi-player game models (alias concurrent game structures) and coalition effectivity models turn out to be intimately related, while alternating epistemic transition systems share much of their philosophical and formal apparatus. Our approach is constructive: we present ways to transform between different types of models and languages.     

Epistemic closure,assumptions and topics of inquiry

According to the principle of epistemic closure, knowledge is closed under known implication. The principle is intuitive but it is problematic in some cases. Suppose you know you have hands and you know that ‘I have hands’ implies ‘I am not a brain-in-a-vat’. Does it follow that you know you are not a brain-in-a-vat? It seems not; it should not be so easy to refute skepticism. In this and similar cases, we are confronted with a puzzle: epistemic closure is an intuitive principle, but at times, it does not seem that we know by implication. In response to this puzzle, the literature has been mostly polarized between those who are willing to do away with epistemic closure and those who think we cannot live without it. But there is a third way. Here I formulate a restricted version of the principle of epistemic closure. In the standard version, the principle can range over any proposition; in the restricted version, it can only range over those propositions that are within the limits of a given epistemic inquiry and that do not constitute the underlying assumptions of the inquiry. If we adopt the restricted version, I argue, we can preserve the advantages associated with closure, while at the same time avoiding the puzzle I’ve described. My discussion also yields an insight into the nature of knowledge. I argue that knowledge is best understood as a topic-restricted notion, and that such a conception is a natural one given our limited cognitive resources.     

Dogmatism repuzzled

Harman and Lewis credit Kripke with having formulated a puzzle that seems to show that knowledge entails dogmatism. The puzzle is widely regarded as having been solved. In this paper we argue that this standard solution, in its various versions, addresses only a limited aspect of the puzzle and holds no promise of fully resolving it. Analyzing this failure and the proper rendering of the puzzle, it is suggested that it poses a significant challenge for the defense of epistemic closure.     

An intensional epistemic logic

One of the fundamental properties inclassical equational reasoning isLeibniz's principle of substitution. Unfortunately, this propertydoes not hold instandard epistemic logic. Furthermore,Herbrand's lifting theorem which isessential to thecompleteness ofresolution andParamodulation in theclassical first order logic (FOL), turns out to be invalid in standard epistemic logic. In particular, unlike classical logic, there is no skolemization normal form for standard epistemic logic. To solve these problems, we introduce anintensional epistemic logic, based on avariation of Kripke's possible-worlds semantics that need not have a constant domain. We show how a weaker notion of substitution through indexed terms can retain the Herbrand theorem. We prove how the logic can yield a satisfibility preserving skolemization form. In particular, we present an intensional principle for unifing indexed terms. Finally, we describe asound andcomplete inference system for a Horn subset of the logic withequality, based onepistemic SLD-resolution.     

佛教逻辑学的论辩解释与认知解释——陈那、法称与因明

佛教逻辑有别于西方形式逻辑的一项重要特征,在于对论证前提为真的强调,并在此基础上提出了著名的"因三相"理论。论证前提的真,在陈那著作中又被理解为辩论主体将该前提确定为真。这种"确定"体现为文献中对"极成"(prasiddha)、"成"(siddha)、"决定"(ni?cita)、"见"(d???a)、"已知"(vidita)的强调。这些表达辩论者认知状态的词汇,皆可概括为佛教逻辑中的"认知算子"(epistemic operator)。本文通过研究东亚因明与法称两个传统对陈那《正理门论》中"决定同许"的理论设定的不同解释,说明因明传统在陈那奠定的方向上,进一步采取了"论辩解释"(dialectic interpretation),将"确定为真"解释为在辩论的情境中为辩论的双方承认为真(共许、同许)。法称《释量论自注》对陈那"决定同许"的解释,则表明由他开启的传统在陈那的基础上,进一步采取了"认知解释"(epistemic interpretation),将"确定为真"解释为在认识论的意义上得到确定(ni?cita/ni?caya,决定),即为有效认知的手段(量)所证成。这是因明传统与法称传统的一项根本差异。因明传统对辩论术的关注,极有可能反映了法称以前印度学界对陈那思想的诠释路径。     

Aristotle on a Puzzle about Logical Consequence: Necessity of Being vs. Necessity of Saying

In the Posterior Analytics (I 6, 75a18–27) Aristotle discusses a puzzle which endangers the possibility of inferring a non-necessary conclusion. His solution relies on the distinction between the necessity of the conclusion's being the case and the necessity of admitting the conclusion once one has admitted the premisses. The former is a factual necessity, whereas the latter is meant to be a normative or deontic necessity that is independent of the facts stated by the premisses and the conclusion. This paper maintains that Aristotle resorts to this distinction because he thinks that, as long as it is conceived as a factual relation, logical consequence cannot exist independently of the facts expressed by the premisses and the conclusion. As a corollary, the necessity of such a consequence relation always requires the necessity of these facts. Aristotle holds this factual conception of logical consequence responsible for the puzzle, since it cannot account for valid syllogisms with contingent or false premisses. The alternative conception of necessity is then introduced by him in order to make good this deficiency. The distinction between the necessity of being and the necessity of saying was revived by the Oxford logician E. W. B. Joseph, and taken over by Frank Ramsey in his seminal Truth and Probability, but has not received attention from recent interpreters of Aristotle's logic. This paper, however, argues that, in spite of its intrinsic interest, the distinction bore no significant fruit in Aristotle's logical doctrine.     

The weight of facts: A puzzle about perception,reasons and deliberation

How should we understand the epistemic role of perception? According to epistemological disjunctivism (ED), a subject’s perceptual knowledge that p is to be explained in terms of the subject believing that p for a factive and reflectively accessible reason. I argue that ED raises far‐reaching questions for rationality and deliberation; I illustrate those questions by setting up a puzzle about belief‐suspension, and I argue that ED does not have the resources to make sense of the rationality of belief‐suspension in cases in which suspending is clearly rational. The conclusion that I draw from the puzzle is mainly negative: the epistemic contribution of perception cannot be explained in terms of a warrant‐conferring relation between perception and belief. However, toward the end, I sketch a positive picture of the epistemic role of perception in terms of a direct explanatory relation between perception and knowledge.     

The Epistemic Value of Emotions in Politics

In this paper, I consider emotional reactions in response to political facts, and I investigate how they may provide relevant knowledge about those facts. I assess the value of such knowledge, both from an epistemic and a political perspective. Concerning the epistemic part, I argue that, although emotions are not in themselves sufficient to ground evaluative knowledge about political facts, they can do so within a network of further coherent epistemic attitudes about those facts. With regards to the political part, I argue that the contribution of emotions to evaluative knowledge about political facts, is indeed politically valuable. To develop my argument, I show first that an evaluative kind of knowledge is relevant for reaching a sophisticated level of political cognition, and second that emotions contribute distinctively to this kind of knowledge. I conclude that, when emotional experiences towards political events are coupled with an adequate factual knowledge about those events, they can ground a distinctive evaluative knowledge about those events, and such knowledge is relevant both from an epistemic and a political perspective.     

The Puzzle of Factual Praise

It seems that we are not willing to give up the intuitions that (1) works of fiction are free from the constraints of historical truth and (2) historical inaccuracies sometimes count against the artistic value of works of fiction. Christopher Bartel calls this the puzzle of historical criticism. I argue that this puzzle extends beyond historical facts. While it is especially salient that historical accuracy at times appears relevant to the evaluation of fictional works, such relevance appears to be a feature of facts in general. I then propose a partial strategy for resolving the puzzle.     

Some Modifications of Carnap’s Modal Logic

In this paper, Carnap??s modal logic C is reconstructed. It is shown that the Carnapian approach enables us to create some epistemic logics in a relatively straight-forward way. These epistemic modifications of C are axiomatized and one of them is compared with intuitionistic logic. At the end of the paper, some connections between this epistemic logic and Medvedev??s logic of finite problems and inquisitive semantics are shortly discussed.