Special issue of Philosophical Studies
An International Journal for Philosophy in the Analytic tradition

Guest-edited by

Vincent F. Hendricks

Special issue, Philosophical Studies, March 2006



Contemporary epistemologists are roughly divided into those relying largely on common-sense considerations and focusing on examples and counterexamples for advancing or rejecting various epistemological theses, and those applying a variety of tools and methods from logic, computability theory or probability theory to the theory of knowledge. The two sorts, and the traditions to which they hitherto are taken to belong, have unfortunately proceeded largely in isolation from one another. But on closer examination the approaches have much in common, may be bridged for their mutual benefit and the advancement of epistemology in general. Here are 7 ways of doing it as the invited papers in this special issue of Philosophical Studies demonstrate the fruitful interaction between informal considerations and various formal apparata in order to support, sharpen, undermine, realize, or contribute in some other pertinent way to fundamental epistemological themes.


  • Horacio Arló-Costa (Carnegie Mellon University)

  • Johan van Benthem (University of Amsterdam / Stanford University)

  • Luc Bovens (London School of Economics / University of Colorado at Boulder)

  • Sven Ove Hansson (Royal Institute of Technology, Stockholm)

  • Vincent F. Hendricks (Roskilde University)

  • Stephan Hartmann (London School of Economics)

  • Matthias Hild (Darden Business School of Administration)

  • Robert Stalnaker (Massachuetts Institute of Technology)

  • John Symons (University of Texas, El Paso)

  • Heinrich Wansing (Technical University of Dresden)


  • Horacio Arló-Costa (Carnegie Mellon University) / TBA

Rationality and Value: The Epistemological Role of Indeterminate and Agent-Dependent Values

An important trend in contemporary epistemology centers on elaborating an old idea of pragmatist pedigree: theory selection (and in general the process of changing view and fixing beliefs) presupposes epistemic values. An elaborated theory along these lines can be found in the writings of Isaac Levi. More recently both Hilary Putnam and Bas van Fraassen have also written books defending interesting variants of this model. And decision-theoretical models of belief change are today more popular also in other areas, like Artificial Intelligence. This article focuses on analyzing the case where epistemic values are indeterminate or vague. According to the theory that thus arises epistemic alternatives need not be fully ordered by an underlying notion of information-value.

Independent work by Amartya Sen analyzing game theoretical situations and strategies leads to an articulation of preferences as chooser- and menu-dependent. Sen argues quite persuasively that this articulation is needed in order to have an adequate notion of rationality covering cases of social interaction where social norms are important. The resulting notion of value also violates standard consistency conditions (like
a, t, WARP, etc) and is therefore compatible with a view of incomplete preferences where the process of choice is an important concern. Sen argues that this fine-grained view of preference is more realistic and that it can be accommodated in a maximizing framework once the axiomatic structure is adjusted.

More realistic accounts of the notion of value involved in the process of fixing beliefs as well as more careful analyses of the notion of preference of interactive agents suggests a picture where alternatives need not be fully ordered and where values are both agent- and menu-dependent. Nevertheless neither the resulting indeterminacy nor the introduction of more fine-grained contextual parameters conspires against the fruitful use of values both in epistemology and in interactive epistemology. On the contrary, it leads to the formulation of slightly more realistic theories of rationality both for single agents and for populations of interacting agents.


  • Johan van Benthem (University of Amsterdam / Stanford University)

From Knowing to Learning

Much of epistemology has been concerned with what it means to possess knowledge, as a sort of 24-carat information that is available to us in reliable ways. Sophisticated new accounts of such intuitions keep appearing until this day. By contrast, much recent work in epistemic logic has concentrated on dynamic mechanisms that produce or modify knowledge and belief - such as speech acts, communication, observation, learning, or even more radical belief revision. In that light, the quality of what we *have* resides largely in the quality of what we *do* - individually, or socially in interaction with others. In our paper, we discuss the broader philosophical relevance of current logics of information update and belief revision, comparing their basic notions to ways of defining knowledge.

  • Luc Bovens (London School of Economics / University of Colorado at Boulder) /
    Stephan Hartmann (London School of Economics)

An Impossibility Result for Coherence Rankings

We receive items of information from independent and partially reliable sources (I&PR). What determines our degree of confidence (DoC) that these items are true? E.g. we are trying to determine the locus of a disease on the human genome. Before running tests there are certain loci we consider more and less likely. We run n tests to identify areas where the disease is located with I&PR instruments. The instruments identify possible loci. Let there be some overlap between the reported areas. Prima facie there are three factors that determine our DoC that the tests are providing correct data, i.e. that the locus of the disease is in the overlap:

(i) How expected are the results? Compare two cases. The only difference is that in case (1) the overlapping area is likely whereas in case (2) it is unlikely. Our DoC will be lower that the locus of the disease is in the overlap in (2) than in (1).

(ii) How reliable are the instruments? Compare two cases. The only difference is that in (1) the tests are quite reliable, while in (2) they are quite unreliable. Our DoC will be lower that the locus of the disease is in the overlap in (2) than in (1).

(iii) How coherent is the information? Compare two cases. The only difference is that in (1) the tests point to precisely the same area A, whereas in (2) they make broad sweeps and the overlap coincides with A. Our DoC will be lower that the locus of the disease is in the overlap in (2) than in (1).

We construct a Bayesian model to determine our DoC that information from I&PR sources is true and show that the following set of prima facie reasonable conditions, constitutive of the Bayesian Coherence Theory of Justification (BCTJ), are jointly inconsistent:

(i) Separability. The more coherent the information is, the more justified we are in believing it, ceteris paribus.

(ii) Holism. The relation ‘...is more coherent than...’ is defined over information sets of any size n.

(iii) Ordering. The relation ‘...is more coherent than...’ is an ordering.

(iv) Probabilism. Coherence rankings are determined by a probabilistic measure defined over information sets.

The reason one is tempted to endorse BCTJ is that it does indeed hold true for the case of n = 1, 2. However, BCTJ is an ill-fated conjecture, since it breaks down for all cases n > 2. This is also why attempts to construct a viable probabilistic measure of coherence have been fatal. We discuss some admittedly costly escape routes to salvage BCTJ.

  • Sven Ove Hansson (Royal Institute of Technology, Stockholm)

Epistemic Coherence and its Formalization

The degree to which our beliefs are mutually compatible and/or supportive is an essential component of a comprehensive account of the mechanisms of belief. It is also an aspect that is unusually well suited for formal treatment. However, in most formal accounts, rather simplistic approaches to coherence have been chosen. In probabilistic representations, coherence is typically an all-or-nothing issue. In non-probabilistic belief revision, it has mostly been taken for granted that logically closed belief sets represent a coherentist and belief bases a foundationalist model of belief. In the present contribution it is argued that a more elaborate representation of coherence is needed, and an outline of such a representation is presented.

  • Matthias Hild (Darden Business School of Administration)


  • Robert Stalnaker (Massachuetts Institute of Technology)

Knowledge and Belief, Rational Action and Interaction

Interactive epistemology - the application of epistemic logic and semantics to game theory - throws light both on some patterns of strategic reasoning (such as backward induction reasoning) and also on some general questions about the nature of knowledge and the relation between knowledge and belief. Specifically, the effect of the assumption that the players in a game have common knowledge that they all are rational depends on exactly what is assumed about knowledge. In this paper, I will explore some different assumptions about knowledge, and trace some of their consequences in a game theoretic setting. I will suggest that the application of epistemic logic in a theory of practical strategic reasoning helps to connect formal questions about the logic of knowledge with some classical problems of substantive epistemology.

  • Heinrich Wansing (Technical University of Dresden) / TBA

Doxastic decisions, epistemic justification, and the logic of agency

A prominent issue in mainstream epistemology is the controversy about doxastic obligations and doxastic voluntarism. In the present paper it is argued that this discussion can greatly benefit from forging links with formal epistemology, namely the modal logic of agency, belief, and obligation. We shall suggest a stit-theory-based semantics for deontic doxastic logic and claim that this is helpful and illuminating in dealing with the mentioned intricate and important problems from mainstream epistemology. Moreover, it is argued that this linking is of mutual benefit. Simple observations concerning other-agent nestings of stit operators may help clarifying issues about making belief and responsibility for beliefs of others.

Keywords: doxastic obligations, doxastic voluntarism, doxastic logic, deontic logic, agency, stit-theory