Belief revision,epistemic conditionals and the Ramsey test

Epistemic conditionals have often been thought to satisfy the Ramsey test (RT): If A, then B is acceptable in a belief state G if and only if B should be accepted upon revising G with A. But as Peter Gärdenfors has shown, RT conflicts with the intuitively plausible condition of Preservation on belief revision. We investigate what happens if (a) RT is retained while Preservation is weakened, or (b) vice versa. We also generalize Gärdenfors' approach by treating belief revision as a relation rather than as a function.In our semantic approach, the same relation is used to model belief revision and to give truth-conditions for conditionals. The approach validates a weak version of the Ramsey Test (WRR) — essentially, a restriction of RT to maximally consistent belief states.We prove that alternatives (a) and (b) are both consistent, but argue that (b) is philosophically more promising. Gärdenfors' belief-revision axioms are compatible with WRR together with RT from left to right: the only direction of the test that is defensible on intuitive grounds.An earlier version of this paper was presented at the conference on the dynamics of knowledge and belief at Lund University, 24–26 August 1989. We wish to thank Sven Danielsson, Peter Gärdenfors, Sören Halldén, David Makinson, Hugh Mellor, Michael Morreau, Nils-Eric Sahlin and Brian Skyrms for their very helpful suggestions and remarks. We are also grateful for thought-provoking criticism and comments from two anonymous referees.     

Non‐epistemic perception as technology

Some epistemologists and philosophers of mind hold that the non‐epistemic perceptual relation of which feature‐seeing and object‐seeing are special cases is the foundation of perceptual knowledge. This paper argues that such relations are best understood as having only a technological role in explaining perceptual knowledge. After introducing the opposing view in §1, §2 considers why its defenders deny that some cases in which one has perceptual knowledge without the relevant acquaintance relations are counterexamples, detailing their case for lurking inferential epistemology. §§3–4 suggest that this strategy fails in many other cases. While there is a computational tale that might be deemed ‘inferential’ in these cases, there is no corresponding tale in epistemic structure, not even if one rejects what Siegel (2017) calls the ‘Reckoning Model’ of inference. §5 offers a more fundamental dilemma. §6 concludes that there is only a technological role for non‐epistemic perception in grounding perceptual knowledge, but allows that it might play a more‐than‐technological role elsewhere.     

Chisholm's Internalism and Its Consequences

Abstract: Among the important themes in Roderick Chisholm's epistemology are his commitment to internalism, his defense of the independence of epistemology from empirical science, and his assumption that we do know most of what we initially think we know. In “Roderick Chisholm and the Shaping of American Epistemology” Hilary Kornblith argues that Chisholm's views lead to a radical divorce between the factors that justify beliefs and the factors that cause beliefs, that Chisholm's views have the consequence that there is no connection between justification and truth, and that Chisholm's kind of epistemology is unable to give epistemic advice. I argue that Chisholm's views do not have these consequences.     

Surface perception and the generic view principle

The hypothesis that perceptual experience can be understood in terms of rule-based processing has strongly influenced recent theories of visual surface perception. However, many of the rules that these theories propose apply only in relatively restricted situations. I suggest that more general and robust principles for reducing perceptual ambiguity are available, such as the generic view principle (GVP) described here. According to the GVP, vision assumes that qualitative (e.g. topological) image structure is stable with respect to small changes of viewpoint. Some consequences of the GVP for visual surfaces, including illusory surfaces, are described. I also demonstrate the decisive role of real and illusory background surfaces in specifying the 3-D shape and layout of visual objects and scenes.     

Propositional epistemic luck,epistemic risk,and epistemic justification

If a subject has a true belief, and she has good evidence for it, and there’s no evidence against it, why should it matter if she doesn’t believe on the basis of the good available evidence? After all, properly based beliefs are no likelier to be true than their corresponding improperly based beliefs, as long as the subject possesses the same good evidence in both cases. And yet it clearly does matter. The aim of this paper is to explain why, and in the process delineate a species of epistemic luck that has hitherto gone unnoticed—what we call propositional epistemic luck—but which we claim is crucial to accounting for the importance of proper basing. As we will see, in order to understand why this type of epistemic luck is malignant, we also need to reflect on the relationship between epistemic luck and epistemic risk.     

Scepticism,epistemic luck,and epistemic angst

A commonly expressed worry in the contemporary literature on the problem of epistemological scepticism is that there is something deeply intellectually unsatisfying about the dominant anti-sceptical theories. In this paper I outline the main approaches to scepticism and argue that they each fail to capture what is essential to the sceptical challenge because they fail to fully understand the role that the problem of epistemic luck plays in that challenge. I further argue that scepticism is best thought of not as a quandary directed at our possession of knowledge simpliciter, but rather as concerned with a specific kind of knowledge that is epistemically desirable. On this view, the source of scepticism lies in a peculiarly epistemic form of angst.

It is always by favour of Nature that one knows something.     

Testimony,epistemic egoism,and epistemic credit

It is generally acknowledged that testifiers can play a central role in the production of knowledge and other valuable epistemic states in others. But does such a role warrant any form of epistemic credit and is an agent more successful qua epistemic agent insofar as she is a successful testifier? I here propose an affirmative answer to both questions. The core of the current paper consists in a sustained defense of this proposal against a series of objections. I further argue that the proposal allows us to recognize an important additional epistemic harm that arises in cases of testimonial injustice beyond those described by Miranda Fricker. Finally, I conclude by distinguishing between four kinds of credit—distinctions that allow us to avoid inappropriately attributing epistemic credit in problematic cases. If the current proposal is correct, our understanding of successful epistemic agents needs to be significantly modified in order to take into account their role in producing epistemically valuable states in others.     

A puzzle for epistemic WAMs

Synthese - In recent literature, a very popular position about the normativity of assertion claims that standards for epistemically proper assertion vary with practical context, while standards for...     

Mandarin speech perception by ear and eye follows a universal principle

In this study, the nature of speech perception of native Mandarin Chinese was compared with that of American English speakers, using synthetic visual and auditory continua (from /ba/ to /da/) in an expanded factorial design. In Experiment 1, speakers identified synthetic unimodal and bimodal speech syllables as either /ba/ or /da/. In Experiment 2, Mandarin speakers were given nine possible response alternatives. Syllable identification was influenced by both visual and auditory sources of information for both Mandarin and English speakers. Performance was better described by the fuzzy logical model of perception than by an auditory dominance model or a weighted-averaging model. Overall, the results are consistent with the idea that although there may be differences in information (which reflect differences in phonemic repertoires, phonetic realizations of the syllables, and the phonotactic constraints of languages), the underlying nature of audiovisual speech processing is similar across languages.