I explore the prospects for modelling epistemic rationality (in the probabilist setting) via an epistemic decision theory, in a consequentialist spirit. Previous work has focused on cases in which the truth-values of the propositions in which the agent is selecting credences do not depend, either causally or merely evidentially, on the agent’s choice of credences. Relaxing that restriction leads to a proliferation of puzzle cases and theories to deal with them, including epistemic analogues of evidential and causal decision theory, and (...) of the Newcomb Problem and ‘Psychopath Button’ Problem. A variant of causal epistemic decision theory deals well with most cases. However, there is a recalcitrant class of problem cases for which no epistemic decision theory seems able to match our intuitive judgements of epistemic rationality. This lends both precision and credence to the view that there is a fundamental mismatch between epistemic consequentialism and the intuitive notion of epistemic rationality; the implications for understanding the latter are briefly discussed. (shrink)

Few concepts have been considered as essential to the theory of knowledge and rational belief as that of evidence. The simplest theory which accounts for this is evidentialism, the view that epistemic justification for belief--the kind of justification typically taken to be required for knowledge--is determined solely by considerations pertaining to one's evidence. In this ground-breaking book, leading epistemologists from across the spectrum challenge and refine evidentialism, sometimes suggesting that it needs to be expanded in quite surprising directions. Following this, (...) the twin pillars of contemporary evidentialism--Earl Conee and Richard Feldman--respond to each essay. This engaging debate covers a vast number of issues, and will illuminate and inform. (shrink)

In his “A new argument for evidentialism” (Shah, Philos Q 56(225): 481–498, 2006 ), Nishi Shah argues that the best explanation of a feature of deliberation whether to believe that p which he calls transparency entails that only evidence can be reason to believe that p. I show that his argument fails because a crucial lemma that his argument appeals to cannot be supported without assuming evidentialism to be true in the first place.

Evidentialists maintain that epistemic justification is strictly a function of the evidence one has at the moment of belief. I argue here, on the basis of two kinds of cases, that the possession of good evidence is an insuflicient basis for justification. I go on to propose a modification of evidentialism according to which justification sometimes requires intellectually virtuous agency. The discussion thereby underscores an important point of contact between evidentialism and the more recent enterprise of virtue epistemology.

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)

When we deliberate whether to believe some proposition, we feel immediately compelled to look for evidence of its truth. Philosophers have labelled this feature of doxastic deliberation 'transparency'. I argue that resolving the disagreement in the ethics of belief between evidentialists and pragmatists turns on the correct explanation of transparency. My hypothesis is that it reflects a conceptual truth about belief: a belief that p is correct if and only if p. This normative truth entails that only evidence can be (...) a reason for belief. Although evidentialism does not follow directly from the mere psychological truth that we cannot believe for non-evidential reasons, it does follow directly from the normative conceptual truth about belief which explains why we cannot do so. (shrink)

The pragmatic character of the Dutch book argument makes it unsuitable as an "epistemic" justification for the fundamental probabilist dogma that rational partial beliefs must conform to the axioms of probability. To secure an appropriately epistemic justification for this conclusion, one must explain what it means for a system of partial beliefs to accurately represent the state of the world, and then show that partial beliefs that violate the laws of probability are invariably less accurate than they could be otherwise. (...) The first task can be accomplished once we realize that the accuracy of systems of partial beliefs can be measured on a gradational scale that satisfies a small set of formal constraints, each of which has a sound epistemic motivation. When accuracy is measured in this way it can be shown that any system of degrees of belief that violates the axioms of probability can be replaced by an alternative system that obeys the axioms and yet is more accurate in every possible world. Since epistemically rational agents must strive to hold accurate beliefs, this establishes conformity with the axioms of probability as a norm of epistemic rationality whatever its prudential merits or defects might be. (shrink)

From Descartes to Popper, philosophers have criticized and tried to improve the strategies of reasoning invoked in science and in everyday life. In recent years leading cognitive psychologists have painted a detailed, controversial, and highly critical portrait of common sense reasoning. Stephen Stich begins with a spirited defense of this work and a critique of those writers who argue that widespread irrationality is a biological or conceptual impossibility.Stich then explores the nature of rationality and irrationality: What is it that distinguishes (...) good reasoning from bad? He rejects the most widely accepted approaches to this question approaches which unpack rationality by appeal to truth, to reflective equilibrium or conceptual analysis. The alternative he defends grows out of the pragmatic tradition in which reasoning is viewed as a cognitive tool. Stich's version of pragmatism leads to a radical epistemic relativism and he argues that the widespread abhorrence of relativism is ill founded. (shrink)

Suppose you decide or promise to do something that you have evidence is difficult to do. Should you believe that you will do it? On the one hand, if you believe that you will do it, your belief goes against the evidence—since having evidence that it’s difficult to do it constitutes evidence that it is likely that you won’t do it. On the other hand, if you don’t believe that you will do it but instead believe, as your evidence suggests, (...) that it is likely that you will fail, your decision is not serious and your promise is not sincere. This problem—I call it the Epistemological Problem of Difficult Action—is a pressing philosophical problem that each of us faces. In this paper I consider several possible responses to it. I conclude that the right response is to say that we should believe against the evidence. Cases in which we decide or promise to do something that we have evidence is difficult to do are the best counterexamples to evidentialism. (shrink)

The internalism-externalism debate is one of the oldest debates in epistemology. Internalists assert that the justification of our beliefs can only depend on facts internal to us, while externalists insist that justification can depend on additional, for example environmental, factors. Clayton Littlejohn proposes and defends a new strategy for resolving this debate. Focussing on the connections between practical and theoretical reason, he explores the question of whether the priority of the good to the right might be used to defend an (...) epistemological version of consequentialism, and proceeds to formulate a new 'deontological externalist' view. On this view, the justificatory status of a belief depends upon whether it is fit for the purposes of practical reasoning. Only beliefs that meet externalist standards are fit for such a purpose. If we want to understand how a wide range of norms (e.g., moral norms) apply to rational agents regardless of what their evidence or outlook is like, we have to embrace an externalist account of the justification. (shrink)

Evidentialism is a popular theory of epistemic justification, yet, as early proponents of the theory Earl Conee and Richard Feldman admit, there are many elements that must be developed before Evidentialism can provide a full account of epistemic justification, or well-founded belief. It is the aim of this book to provide the details that are lacking; here McCain moves past Evidentialism as a mere schema by putting forward and defending a full-fledged theory of epistemic justification. In this book McCain offers (...) novel approaches to several elements of well-founded belief. Key among these are an original account of what it takes to have information as evidence, an account of epistemic support in terms of explanation, and a causal account of the basing relation that is far superior to previous accounts. The result is a fully developed Evidentialist account of well-founded belief. (shrink)

Richard Pettigrew offers an extended investigation into a particular way of justifying the rational principles that govern our credences. The main principles that he justifies are the central tenets of Bayesian epistemology, though many other related principles are discussed along the way. Pettigrew looks to decision theory in order to ground his argument. He treats an agent's credences as if they were a choice she makes between different options, gives an account of the purely epistemic utility enjoyed by different sets (...) of credences, and then appeals to the principles of decision theory to show that, when epistemic utility is measured in this way, the credences that violate the principles listed above are ruled out as irrational. The account of epistemic utility set out here is the veritist's: the sole fundamental source of epistemic utility for credences is their accuracy. Thus, Pettigrew conducts an investigation in the version of epistemic utility theory known as accuracy-first epistemology. (shrink)

We argue that David Lewis’s principal principle implies a version of the principle of indifference. The same is true for similar principles that need to appeal to the concept of admissibility. Such principles are thus in accord with objective Bayesianism, but in tension with subjective Bayesianism. 1 The Argument2 Some Objections Met.

This paper defends a principle I call Equal Treatment, according to which the rationality of a belief is determined in precisely the same way as the rationality of any other state. For example, if wearing a raincoat is rational just in case doing so maximizes expected value, then believing some proposition P is rational just in case doing so maximizes expected value. This contrasts with the popular view that the rationality of belief is determined by evidential support. It also contrasts (...) with the common idea that in the case of belief, there are two different incommensurable senses of rationality, one of which is distinctively epistemic. I present considerations that favor Equal Treatment over these two alternatives, reply to objections, and criticize some arguments for Evidentialism. I also show how Equal Treatment opens the door to a distinctive kind of response to skepticism. (shrink)

In Bayesian epistemology, the problem of the priors is this: How should we set our credences (or degrees of belief) in the absence of evidence? That is, how should we set our prior or initial credences, the credences with which we begin our credal life? David Lewis liked to call an agent at the beginning of her credal journey a superbaby. The problem of the priors asks for the norms that govern these superbabies. -/- The Principle of Indifference gives a (...) very restrictive answer. It demands that such an agent divide her credences equally over all possibilities. That is, according to the Principle of Indifference, only one initial credence function is permissible, namely, the uniform distribution. In this paper, we offer a novel argument for the Principle of Indifference. I call it the Argument from Accuracy. (shrink)

This paper shows that strict evidentialism about normative reasons for belief is inconsistent with taking truth to be the source of normative reasons for belief. It does so by showing that there are circumstances in which one can know what truth requires one to believe, yet still lack evidence for the contents of that belief.

One of the fundamental problems of epistemology is to say when the evidence in an agent’s possession justifies the beliefs she holds. In this paper and its prequel, we defend the Bayesian solution to this problem by appealing to the following fundamental norm: Accuracy An epistemic agent ought to minimize the inaccuracy of her partial beliefs. In the prequel, we made this norm mathematically precise; in this paper, we derive its consequences. We show that the two core tenets of Bayesianism (...) follow from the norm, while the characteristic claim of the Objectivist Bayesian follows from the norm along with an extra assumption. Finally, we consider Richard Jeffrey’s proposed generalization of conditionalization. We show not only that his rule cannot be derived from the norm, unless the requirement of Rigidity is imposed from the start, but further that the norm reveals it to be illegitimate. We end by deriving an alternative updating rule for those cases in which Jeffrey’s is usually supposed to apply. (shrink)

One of the fundamental problems of epistemology is to say when the evidence in an agent’s possession justifies the beliefs she holds. In this paper and its sequel, we defend the Bayesian solution to this problem by appealing to the following fundamental norm: Accuracy An epistemic agent ought to minimize the inaccuracy of her partial beliefs. In this paper, we make this norm mathematically precise in various ways. We describe three epistemic dilemmas that an agent might face if she attempts (...) to follow Accuracy, and we show that the only inaccuracy measures that do not give rise to such dilemmas are the quadratic inaccuracy measures. In the sequel, we derive the main tenets of Bayesianism from the relevant mathematical versions of Accuracy to which this characterization of the legitimate inaccuracy measures gives rise, but we also show that Jeffrey conditionalization has to be replaced by a different method of update in order for Accuracy to be satisfied. (shrink)

fits our evidence.[1] I will propose some potential counter-examples to test this evidentialist thesis. My main intention in presenting the “counter-examples” is to better understand Feldman’s evidentialism, and evidentialism in general. How are we to understand what our evidence is, how it works, and how are we to understand the phrase “epistemically ought to believe” such that evidentialism might make sense as a plausible thesis in light of the examples? Of course, we may decide that there’s no such way to (...) understand evidentialism -- that it just isn’t a plausible thesis. I must admit that my suspicions lean in that direction. But the potential counter-examples are put forward, not in a refutational spirit (though I have nothing against good refutations in philosophy), but as an invitation to evidentialists and potential evidentialists to refine and/or explain their thesis in light of the at least apparent problems that the examples highlight. (shrink)

A normative Bayesian theory of deliberation and judgement requires a procedure for merging the evidence of a collection of agents. In order to provide such a procedure, one needs to ask what the evidence is that grounds Bayesian probabilities. After finding fault with several views on the nature of evidence (the views that evidence is knowledge; that evidence is whatever is fully believed; that evidence is observationally set credence; that evidence is information), it is argued that evidence is whatever is (...) rationally taken for granted. This view is shown to have consequences for an account of merging evidence, and it is argued that standard axioms for merging need to be altered somewhat. (shrink)

Objective Bayesian epistemology invokes three norms: the strengths of our beliefs should be probabilities, they should be calibrated to our evidence of physical probabilities, and they should otherwise equivocate sufficiently between the basic propositions that we can express. The three norms are sometimes explicated by appealing to the maximum entropy principle, which says that a belief function should be a probability function, from all those that are calibrated to evidence, that has maximum entropy. However, the three norms of objective Bayesianism (...) are usually justified in different ways. In this paper we show that the three norms can all be subsumed under a single justification in terms of minimising worst-case expected loss. This, in turn, is equivalent to maximising a generalised notion of entropy. We suggest that requiring language invariance, in addition to minimising worst-case expected loss, motivates maximisation of standard entropy as opposed to maximisation of other instances of generalised entropy. Our argument also provides a qualified justification for updating degrees of belief by Bayesian conditionalisation. However, conditional probabilities play a less central part in the objective Bayesian account than they do under the subjective view of Bayesianism, leading to a reduced role for Bayes’ Theorem. (shrink)

To the extent that we have reasons to avoid these “bad B -properties”, these arguments provide reasons not to have an incoherent credence function b — and perhaps even reasons to have a coherent one. But, note that these two traditional arguments for probabilism involve what might be called “pragmatic” reasons (not) to be (in)coherent. In the case of the Dutch Book argument, the “bad” property is pragmatically bad (to the extent that one values money). But, it is not clear (...) whether the DBA pinpoints any epistemic defect of incoherent agents. The same can be said for Representation Theorem arguments, since they involve the structure of an agent’s preferences. (shrink)

Logic is a field studied mainly by researchers and students of philosophy, mathematics and computing. Inductive logic seeks to determine the extent to which the premises of an argument entail its conclusion, aiming to provide a theory of how one should reason in the face of uncertainty. It has applications to decision making and artificial intelligence, as well as how scientists should reason when not in possession of the full facts. In this work, Jon Williamson embarks on a quest to (...) find a general, reasonable, applicable inductive logic (GRAIL), all the while examining why pioneers such as Ludwig Wittgenstein and Rudolf Carnap did not entirely succeed in this task. (shrink)

This paper presents a new argument for the Principle of Indifference. This argument can be thought of in two ways: as a pragmatic argument, justifying the principle as needing to hold if one is to minimise worst-case expected loss, or as an epistemic argument, justifying the principle as needing to hold in order to minimise worst-case expected inaccuracy. The question arises as to which interpretation is preferable. I show that the epistemic argument contradicts Evidentialism and suggest that the relative plausibility (...) of Evidentialism provides grounds to prefer the pragmatic interpretation. If this is right, it extends to a general preference for pragmatic arguments for the Principle of Indifference, and also to a general preference for pragmatic arguments for other norms of Bayesian epistemology. (shrink)

Evidentialism as Earl Conee and Richard Feldman present it is a philosophy with distinct aspects or sides: Evidentialism as a conceptual analysis of epistemic justification, and as a prescriptive ethics of belief. I argue that Conee and Feldman's ethics of belief has 'weak roots and sour fruits.' It has "weak roots" because it is premised on their account of epistemic justification qua synchronic rationality, and this is neither necessary nor sufficient for knowledge. Also, Conee and Feldman's thesis O2 (An agent (...) ought to always have just exactly that attitude towards a proposition supported by his / her evidence at that particular moment) is not support by in their “Ethics of Belief” article by V3 (Being synchronically rational at every moment is uniformly what it is to constitute epistemic success and to maximize epistemic value). That austere ethics of belief has "sour fruits" because the austere evidentialist ethic of belief is unable to support reasonable disagreement, and conflates psychographic contrareity epistemic fault or irrationality. The "hard line" and universal agnostic suspension it takes as the only rational stances of disagreement are really caricatures of different extreme responses to contrareity found among dogmatists and skeptics, respectively. I contrast this with John Rawls' understanding of "reasonable pluralism" and of the many sources of faultless disagreement over what Rawls termed comprehensive conceptions of the good. (shrink)

A study of the possibility of casting plausible matheamtical inference in Bayesian terms.

A number of philosophers have claimed that non-evidential considerations cannot play a role in doxastic deliberation as motivating reasons to believe a proposition. This claim, interesting in its own right, naturally lends itself to use in a range of arguments for a wide array of substantive philosophical theses. I argue, by way of a counterexample, that the claim to which all these arguments appeal is false. I then consider, and reply to, seven objections to my counterexample. Finally, as a way (...) of softening the blow, I show how the counterexample itself suggests a plausible diagnosis of why this claim has seemed so plausible to so many. (shrink)

Objective Bayesianism is a methodological theory that is currently applied in statistics, philosophy, artificial intelligence, physics and other sciences. This book develops the formal and philosophical foundations of the theory, at a level accessible to a graduate student with some familiarity with mathematical notation.

Nishi Shah has recently argued that transparency in doxastic deliberation supports a strict version of evidentialism about epistemic reasons. I argue that Shah's argument relies on a principle that is incompatible with the strict version of evidentialism Shah wishes to advocate.