Brian Weatherson

Recently, Timothy Williamson has argued that considerations about margins of errors can generate a new class of cases where agents have justified true beliefs without knowledge. I think this is a great argument, and it has a number of interesting philosophical conclusions. In this note I’m going to go over the assumptions of Williamson’s argument. I’m going to argue that the assumptions which generate the justification without knowledge are true. I’m then going to go over some of the recent arguments in epistemology that are refuted by Williamson’s work. And I’m going to end with an admittedly inconclusive discussion of what we can know when using an imperfect measuring device.

Many writers have held that in his later work, David Lewis adopted a theory of predicate meaning such that the meaning of a predicate is the most natural property that is (mostly) consistent with the way the predicate is used. That orthodox interpretation is shared by both supporters and critics of Lewis's theory of meaning, but it has recently been strongly criticised by Wolfgang Schwarz. In this paper, I accept many of Schwarze's criticisms of the orthodox interpretation, and add some more. But I also argue that the orthodox interpretation has a grain of truth in it, and seeing that helps us appreciate the strength of Lewis's late theory of meaning.

This paper is about three of the most prominent debates in modern epistemology. The conclusion is that three prima facie appealing positions in these debates cannot be held simultaneously. The first debate is scepticism vs anti-scepticism. My conclusions apply to most kinds of debates between sceptics and their opponents, but I will focus on the inductive sceptic, who claims we cannot come to know what will happen in the future by induction. This is a fairly weak kind of scepticism, and I suspect many philosophers who are generally anti-sceptical are attracted by this kind of scepticism. Still, even this kind of scepticism is quite unintuitive. I’m pretty sure I know (1) on the basis of induction. (1) It will snow in Ithaca next winter. Although I am taking a very strong version of anti-scepticism to be intuitively true here, the points I make will generalise to most other versions of scepticism. (Focussing on the inductive sceptic avoids some potential complications that I will note as they arise.) The second debate is a version of rationalism vs empiricism. The kind of rationalist I have in mind accepts that some deeply contingent propositions can be known a priori, and the empiricist I have in mind denies this. Kripke showed that there are contingent propositions that can be known a priori. One example is Water is the watery stuff of our acquaintance. (‘Watery’ is David Chalmers’s nice term for the properties of water by which folk identify it.) All the examples Kripke gave are of propositions that are, to use Gareth Evans’s term, deeply necessary (Evans, 1979). It is a matter of controversy presently just how to analyse Evans’s concepts of deep necessity and contingency, but most of the controversies are over details that are not important right here. I’ll simply adopt Stephen Yablo’s recent suggestion: a proposition is deeply contingent if it could have turned out to be true, and could have turned out to be false (Yablo, 2002)1. Kripke did not provide examples of any deeply contingent propositions knowable a priori, though nothing he showed rules out their existence..

Gordon Belot has recently developed a novel argument against Bayesianism. He shows that there is an interesting class of problems that, intuitively, no rational belief forming method is likely to get right. But a Bayesian agent’s credence, before the problem starts, that she will get the problem right has to be 1. This is an implausible kind of immodesty on the part of Bayesians. My aim is to show that while this is a good argument against traditional, precise Bayesians, the argument doesn’t neatly extend to imprecise Bayesians. As such, Belot’s argument is a reason to prefer imprecise Bayesianism to precise Bayesianism.

I defend normative externalism from the objection that it cannot account for the wrongfulness of moral recklessness. The defence is fairly simple—there is no wrong of moral recklessness. There is an intuitive argument by analogy that there should be a wrong of moral recklessness, and the bulk of the paper consists of a response to this analogy. A central part of my response is that if people were motivated to avoid moral recklessness, they would have to have an unpleasant sort of motivation, what Michael Smith calls “moral fetishism”.

Orthodox Bayesian decision theory requires an agent’s beliefs representable by a real-valued function, ideally a probability function. Many theorists have argued this is too restrictive; it can be perfectly reasonable to have indeterminate degrees of belief. So doxastic states are ideally representable by a set of probability functions. One consequence of this is that the expected value of a gamble will be imprecise. This paper looks at the attempts to extend Bayesian decision theory to deal with such cases, and concludes that all proposals advanced thus far have been incoherent. A more modest, but coherent, alternative is proposed. Keywords: Imprecise probabilities, Arrow’s theorem.

I consider the problem of how to derive what an agent believes from their credence function and utility function. I argue the best solution of this problem is pragmatic, i.e. it is sensitive to the kinds of choices actually facing the agent. I further argue that this explains why our notion of justified belief appears to be pragmatic, as is argued e.g. by Fantl and McGrath. The notion of epistemic justification is not really a pragmatic notion, but it is being applied to a pragmatically defined concept, i.e. belief.

Data about attitude reports provide some of the most interesting arguments for, and against, various theses of semantic relativism. This paper is a short survey of three such arguments. First, I’ll argue (against recent work by von Fintel and Gillies) that relativists can explain the behaviour of relativistic terms in factive attitude reports. Second, I’ll argue (against Glanzberg) that looking at attitude reports suggests that relativists have a more plausible story to tell than contextualists about the division of labour between semantics and meta-semantics. Finally, I’ll offer a new argument for invariantism (i.e. against both relativism and contextualism) about moral terms. The argument will turn on the observation that the behaviour of normative terms in factive and non-factive attitude reports is quite unlike the behaviour of any other plausibly context-sensitive term. Before that, I’ll start with some taxonomy, just so as it’s clear what the intended conclusions below are supposed to be.

Humeanism is “the thesis that the whole truth about a world like ours supervenes on the spatiotemporal distribution of local qualities.” (Lewis, 1994, 473) Since the whole truth about our world contains truths about causation, causation must be located in the mosaic of local qualities that the Humean says constitute the whole truth about the world. The most natural ways to do this involve causation being in some sense extrinsic. To take the simplest possible Humean analysis, we might say that c causes e iff throughout the mosaic events of the same type as c are usually followed by events of type e. For short, the causal relation is the constant conjunction relation. Whether this obtains is determined by the mosaic, so this is a Humean theory, but it isn’t determined just by c and e themselves, so whether c causes e is extrinsic to the pair. Now this is obviously a bad theory of causation, but the fact that causation is extrinsic is retained even by good Humean theories of causation. John Hawthorne (2004) objects to this feature of Humeanism. I’m going to argue that his arguments don’t work, but first we need to clear up three preliminaries about causation and intrinsicness.

Sameness and Substance Renewed (hereafter, 2001) is, in effect, a second edition of Wiggins’s 1980 book Sameness and Substance (hereafter, 1980), which in turn expanded and corrected some ideas in his 1967 Identity and Spatio-Temporal Continuity (hereafter, 1967). All three books have similar aims. The first is to argue, primarily against Geach, that identity is absolute not relative. The second is to argue that, despite this, whenever an identity claim a = b is true, there is a sortal f such that a is the same f as b. The biggest difference between 1967 and the two later books is that the later books contain much more detail on what a sortal must be if this claim, called D, is to be both correct and philosophically interesting. The third aim is to apply the first two conclusions to the topic of personal identity.

This paper has three aims. First, I’ll argue that there’s no good reason to accept any kind of ‘easy knowledge’ objection to externalist foundationalism. It might be a little surprising that we can come to know that our perception is accurate by using our perception, but any attempt to argue this is impossible seems to rest on either false premises or fallacious reasoning. Second, there is something defective about using our perception to test whether our perception is working. What this reveals is that there are things we aim for in testing other than knowing that the device being tested is working. I’ll suggest that testing aims for sensitive knowledge that the device is working. Testing a device, such as our perceptual system, by using its own outputs may deliver knowledge, but it can’t deliver sensitive knowledge. So it’s a bad way to test the system. The big conclusion here is that sensitivity is an important epistemic virtue, although it is not necessary for knowledge. Third, I’ll argue that the idea that sensitivity is an epistemic virtue can provide a solution to a tricky puzzle about inductive evidence. This provides another reason for thinking that the conclusion of section two is correct: not all epistemic virtues are to do with knowledge

I defend interest-relative invariantism from a number of recent attacks. One common thread to my response is that interest-relative invariantism is a muchweaker thesis than is often acknowledged, and a number of the attacks only challenge very specific, and I think implausible, versions of it. Another is that a number of the attacks fail to acknowledge how many things we have independent reason to believe knowledge is sensitive to. Whether there is a defeater for someone's knowledge can be sensitive to all manner of features of their environment, as the host of examples from the post-Gettier literature shows. Adding in interest-sensitive defeaters is a much less radical move than most critics claim it is.

The traditional generality problem for process reliabilism concerns the difficulty in identifying each belief forming process with a particular kind of process. Thatidentification is necessary since individual belief forming processes are typically of many kinds, and those kinds may vary in reliability. I raise a new kind of generality problem, one which turns on the difficulty of identifying beliefs with processes by which they were formed. This problem arises because individual beliefs may be the culmination of overlapping processes of distinct lengths, and these processes may differ in reliability. I illustrate the force of this problem with a discussion of recent work on the bootstrapping problem.

In a recent article, Adam Elga outlines a strategy for “Defeating Dr Evil with Self-Locating Belief”. The strategy relies on an indifference principle that is not up to the task. In general, there are two things to dislike about indifference principles: adopting one normally means confusing risk for uncertainty, and they tend to lead to incoherent views in some ‘paradoxical’ situations. I argue that both kinds of objection can be levelled against Elga’s indifference principle. There are also some difficulties with the concept of evidence that Elga uses, and these create further difficulties for the principle.

Many epistemologists hold that an agent can come to justifiably believe that p is true by seeing that it appears that p is true, without having any antecedent reason to believe that visual impressions are generally reliable. Certain reliabilists think this, at least if the agent’s vision is generally reliable. And it is a central tenet of dogmatism (as described by Pryor (2000) and Pryor (2004)) that this is possible. Against these positions it has been argued (e.g. by Cohen (2005) and White (2006)) that this violates some principles from probabilistic learning theory. To see the problem, let’s note what the dogmatist thinks we can learn by paying attention to how things appear. (The reliabilist says the same things, but we’ll focus on the dogmatist.) Suppose an agent receives an appearance that p, and comes to believe that p. Letting Ap be the proposition that it appears to the agent that p, and → be the material implication, we can say that the agent learns that p, and hence is in a position to infer Ap → p, once they receive the evidence Ap.1 This is surprising, because we can prove the following.

Thomas Blackson argues that interest-relative epistemologies cannot explain the irrationality of certain choices when the agent has three possible options. I argue that his examples only refute a subclass of interest-relative theories. In particular, they are good objections to theories that say that what an agent knows depends on the stakes involved in the gambles that she faces. But they are not good objections to theories that say that what an agent knows depends on the odds involved in the gambles that she faces. Indeed, the latter class of theories does a better job than interest-invariant epistemologies of explaining the phenomena he describes.