Selected papers

When what justifies you in believing a proposition is some evidence you have, you are doxastically justified only if you believe that proposition on the basis of that evidence. According to causal theories of basing, this basing relation must be a causal relation. In this article, we discuss the role that defeaters play in an account of this kind. We first argue that doxastic justification for believing a certain proposition requires, not just basing the belief on evidence that one has and that is sufficient to propositionally justify the belief, but also being sensitive to the absence of sufficiently weighty defeaters. We then argue that causal theories of basing have the right kinds of resources to incorporate this role played by defeaters (and the relevant role played by disqualifiers) in the concept of doxastic justification. Our argument borrows from action theory in that it is inspired by similar arguments on behalf of causalist accounts of action and freedom. We end with a discussion of the bearing of our view on Pryor's dogmatism.

Joanthan Weisberg has presented a puzzle for Bayesian epistemologists (Weisberg, 2009, 2015). The puzzle highlights the inability to model a specific kind of defeasibility of evidence in a Bayesian framework. But the puzzle is of much wider interest: it arises not just for Bayesians, and not just for formal modelers, but for any theory which adopts three very plausible principles: the rigidity, symmetry, and defeasibility of evidence. In this paper I first present Weisberg’s puzzle as originally developed, in the context of Bayesian epistemology. Then I show how the problem arises for normal epistemology as well. I offer a solution for the normal puzzle and then carry over that solution to the formal side. I end up by suggesting that taking the puzzle seriously means facing up to the possibility that we cannot give an informative, general characterization of epistemic justification, and that we should instead rest content with a kind of particularism.

Evidentialism and Reliabilism are two of the main contemporary theories of epistemic justification. Some authors have thought that the theories are not incompatible with each other, and that a hybrid theory which incorporates elements of both should be taken into account. More recently, other authors have argued that the resulting theory is well- placed to deal with fine-grained doxastic attitudes (credences). In this paper I review the reasons for adopting this kind of hybrid theory, paying attention to the case of credences and the notion of probability involved in their treatment. I argue that the notion of probability in question can only be an epistemic (or evidential) kind of probability. I conclude that the resulting theory will be incompatible with Reliabilism in one important respect: it cannot deliver on the reductivist promise of Reliabilism. I also argue that attention to the justification of basic beliefs reveals limitations in the Evidentialist framework as well. The theory that results from the right combination of Evidentialism and Reliabilism, therefore, is neither Evidentialist nor Reliabilist.

The two main theories of perceptual reasons in contemporary epistemology can be called Phenomenalism and Factualism. According to Phenomenalism, perceptual reasons are facts about experiences conceived of as phenomenal states, i.e., states individuated by phenomenal character, by what it’s like to be in them. According to Factualism, perceptual reasons are instead facts about the external objects perceived. The main problem with Factualism is that it struggles with bad cases: cases where perceived objects are not what they appear or where there is no perceived object at all. The main problem with Phenomenalism is that it struggles with good cases: cases where everything is perfectly normal and the external object is correctly perceived, so that one’s perceptual beliefs are knowledge. In this paper we show that there is a theory of perceptual reasons that avoids the problems for Factualism and Phenomenalism. We call this view Propositionalism. We use ‘proposition’ broadly to mean the entities that are contents of beliefs and other doxastic attitudes. The key to finding a middle ground between Phenomenalism and Factualism, we claim, is to allow our reasons to be false in bad cases. Despite being false, they are about the external world, not our phenomenal states.

I argue that normative requirements should be interpreted as the conditional obligations of dyadic deontic logic. Semantically, normative requirements are conditionals understood as restrictors, the prevailing view of conditionals in linguistics. This means that Modus Ponens is invalid, even when the premises are known.

It’s complicated.

We argue that we can have false reasons to believe and act.

Difference-making is thought to play an important role in epistemology. It is quite common to suggest, for example, that for a belief to amount to knowledge the world has to make the relevant kind of difference to what is believed. It is also quite common to suggest that for a belief to be justified on the basis of some evidence the evidence must make the relevant kind of difference to what is believed. In this paper we put forth a novel difference-making constraint on evidence and justification–and therefore, given that knowledge entails justification, a constraint on knowledge as well. We motivate such a constraint by means of a parallel with the suggestion that causation is a difference-making relation. In particular, we argue that a recent account of how causes make a difference to their effects can be adapted to explain how evidence makes a difference to justified beliefs. We also show that the proposed difference-making constraint can shed new light on the problem of “easy knowledge.”

imothy Williamson has fruitfully exploited formal resources to shed considerable light on the nature of knowledge. In the paper under examination, Williamson turns his attention to Gettier cases, showing how they can be motivated formally. At the same time, he disparages the kind of justification he thinks gives rise to these cases. He favors instead his own notion of justification for which Gettier cases cannot arise. We take issue both with his disparagement of the kind of justification that figures in Gettier cases and the specifics of the formal motivation.

I argue for a theory that combines elements of Reliabilism and Evidentialism.