Online research in philosophy

Evidentialism is the thesis that a person is justified in believing a proposition iff the person's evidence on balance supports that proposition. In discussing epistemological issues associated with disagreements among epistemic peers, some philosophers have endorsed principles that seem to run contrary to evidentialism, specifying how one should revise one's beliefs in light of disagreement. In this paper, I examine the connection between evidentialism and these principles. I argue that the puzzles about disagreement provide no reason to abandon evidentialism and that there are no true general principles about justified responses to disagreement other than the general evidentialist principle. I then argue that the puzzles about disagreement are primarily puzzles about the evidential impact of higher-order evidence – evidence about the significance or existence of ordinary, or first-order, evidence. I conclude by arguing that such higher-order evidence can often have a profound effect on the justification of first-order beliefs.

Theories of epistemically justified belief have long assumed individualism. In its extreme, or Lockean, form individualism rules out justified belief on testimony by insisting that a subject is justified in believing a proposition only if he or she possesses first-hand justification for it. The skeptical consequences of extreme individualism have led many to adopt a milder version, attributable to Hume, on which a subject is justified in believing a proposition only if he or she is justified in believing that there is testimony in favor of the proposition deriving from a reliable source. I argue that this Humean individualism also leads to skepticism in a wide range of cases; it makes it impossible for a layperson to be justified on expert testimony. In addition, I argue that the apparent motivation for the Humean view, an insistence on intellectual autonomy in justification, does not succeed in motivating it. I then explore the contours of a collectivist view of justification on testimony, with special attention to the place of a subject's intellectual autonomy in such justification. I try to bring empirical results of the psychology of persuasion to bear on the epistemological issues.

My topic in this paper is a particular species of epistemic justification – a species that, following Roderick Firth, I call “propositional justification.”1 Propositional justification is a relation between a person and a proposition. I will say that for S to bear the propositional justification relation to p is for S to be “justified in believing” that p. What is propositional justification? What is it for S to be justified in believing that p? Here’s my answer.

I argue that trustworthiness is an epistemic desideratum. It does not reduce to justified or reliable true belief, but figures in the reason why justified or reliable true beliefs are often valuable. Such beliefs can be precarious. If a belief's being justified requires that the evidence be just as we take it to be, then if we are off even by a little, the belief is unwarranted. Similarly for reliability. Although it satisfies the definition of knowledge, such a belief is not trustworthy. We ought not use it as a basis for inference or action and ought not give others to believe it. The trustworthiness of a belief, I urge, depends on its being backed by reasons—considerations that other members of the appropriate epistemic community cannot reasonably reject. Trustworthiness is intersubjective. It both depends on and contributes to the evolving cognitive values of an epistemic community.

According to the deontological view on justification, being justified in believing some proposition is a matter of having done one's epistemic duty with respect to that proposition. The present paper argues that, given a proper articulation of the deontological view, it is defensible that knowledge is justified true belief, pace virtually all epistemologists since Gettier. One important claim to be argued for is that once it is appreciated that it depends on contextual factors whether a person has done her epistemic duty with respect to a given proposition, many so-called Gettier cases, which are supposed to be cases of justified true belief that are not cases of knowledge, will be seen to be not really cases of justified belief after all. A second important claim is that the remaining alleged Gettier cases can be qualified as cases of knowledge. This requires that we countenance a notion of epistemic luck, but the requisite kind of luck is of a quite benign nature.

According to a common view, the activity of justifying is epistemologically irrelevant: being justified in believing as one does never requires the ability to justify one’s belief. This view runs into trouble regarding the epistemic basing relation, the relation between a person’s belief and the reasons for which the person holds it. The view must appeal to basing relations as part of its account of what it is for a person to be justified in believing as she does, but the view prevents basing relations from doing the needed work. In place of the common view, I propose an account of basing relations which links them to the person’s commitments and hence to her justificatory activity. If this proposal is correct, then positive justificatory status, too, will be conceptually linked to the ability to succeed in the activity of justifying.

In 2004, I explained the absurdity of Moore-paradoxical belief via the syllogism (Williams 2004): (1) All circumstances that justify me in believing that p are circumstances that tend to make me believe that p. (2) All circumstances that tend to make me believe that p are circumstances that justify me in believing that I believe that p. (3) All circumstances that justify me in believing that p are circumstances that justify me in believing that I believe that p. I then took (3) to mean (EP) Whatever justifies me in believing that p justifies me in believing that I believe that p.1 Now suppose that I am justified in believing anything of the omissive Mooreparadoxical form: (Om) p and I do not believe that p. Then I am justified in believing the first conjunct. So by (EP) I am justified in believing that I believe that p. But since I am also justified in believing the second conjunct, I am justified in believing that I do not believe that p. I claimed that this is impossible, because anything that justifies me in believing that something is the case renders me unjustified in believing that it is not the case. This syllogism is plausible from an externalist view of justification, according to which circumstances such as seeming to see rain under normal perceptual conditions, justify me in believing that it is raining. In support of (1), if my apparent perceptions of rain are reliably connected with rain, so as to justify me in thinking that it is raining, they also tend to make me believe that it is raining. In support of (2), my apparent perceptions of rain are also reliably connected with my coming to believe that it is raining. However, Anthony Brueckner (2006) argues that (1) and (EP) are both false once justification is thought of evidentially. Against (EP), he claims that my evidence that p is not evidence that I believe that p unless I possess the evidence, in the sense that I believe it and were I to believe that p on its basis.

The following principles may plausibly be included in a wide range of theories of epistemic justification: (1) There are circumstances in which an agent is justified in believing a falsehood, (2) There are circumstances in which an agent is justified in believing a principle of epistemic justification, (3) Beliefs acquired in compliance with a justifiably-believed epistemic principle are justified. I argue that it follows from these three individually plausible claims that an agent's belief may be both justified and unjustified. I consider how theories may avoid this paradox, and conclude that deontological theories of epistemic justification face considerable, perhaps insurmountable, difficulties.

I am justified in believing that my lottery ticket—call it t1—will not win, on statistical grounds. Those grounds apply equally to any other ticket, so I am justified in believing of any other ticket ti (let i take values from 2 to 1000000) that it will not win. I am not, however, justified in believing the giant conjunctive proposition that t1 will not win & t2 will not win & . . . & t1,000,000 will not win. On the contrary, I am justified in believing that some ticket will win, hence that one of those conjuncts is false. Suggested solution: justified belief is not closed under conjunction. It does not follow from the fact that I am justified in believing p and justified in believing q that I am justified in believing p & q.

Epistemologists often offer theories of justification without paying much attention to the variety and diversity of locutions in which the notion of justification appears. For example, consider the following claims which contain some notion of justification: B is a justified belief, S's belief that p is justified, p is justified for S, S is justified in believing that p, S justifiably believes that p, S's believing p is justified, there is justification for S to believe that p, there is justification for S's believing p, and S has a justification for believing that p. In addition to these passive uses of the notion of justification, there are active uses as well: S justified his belief in p, believing e justifies believing p, etc. The syntactic variety involves semantic difference as well. For example, the proposition S has a justification for believing that p does not entail that S believes p, whereas the proposition S justifiably believes that p does entail that S believes p. Our ultimate goal is to show that this diversity is only superficial by arguing that there is a basic kind of justification. On the way, however, we shall argue that there are three central uses of a notion of justifica- tion in the above list: propositional justification (as in p is justified for S), personal justification (as in S is justified in believing that p) and doxastic justification (as in S's believing p is justified). Our preliminary argument will be that the multiplicity above can be explained in terms of these three locutions, and the substance of our argument will be to show that one of these three is the basic kind of justification. Success in this task will thereby justify, at least in part, the practice of contem- porary epistemologists. Our conclusions, however, shall not be of much comfort to contemporary epistemology, for the way in which the apparent diversity in the uses of the notion of justification is eliminated undermines much of recent epistemology.