According to a traditional Cartesian epistemology of perception, perception does not provide one with direct knowledge of the external world. Instead, your immediate perceptual evidence is limited to facts about your own visual experience, from which conclusions about the external world must be inferred. Cartesianism faces well-known skeptical challenges. But this chapter argues that any anti-Cartesian view strong enough to avoid these challenges must license a way of updating one’s beliefs in response to anticipated experiences that seems diachronically irrational. To (...) avoid this result, the anti-Cartesian must either license an unacceptable epistemic chauvinism, or else claim that merely reflecting on one’s experiences defeats perceptual justification. This leaves us with a puzzle: Although Cartesianism faces problems, avoiding them brings a new set of problems. (shrink)

This paper criticizes phenomenal conservatism––the influential view according to which a subject S’s seeming that P provides S with defeasible justification for believing P. I argue that phenomenal conservatism, if true at all, has a significant limitation: seeming-based justification is elusive because S can easily lose it by just reflecting on her seemings and speculating about their causes––I call this the problem of reflective awareness. Because of this limitation, phenomenal conservatism doesn’t have all the epistemic merits attributed to it by (...) its advocates. If true, phenomenal conservatism would constitute a unified theory of epistemic justification capable of giving everyday epistemic practices a rationale, but it wouldn’t afford us the means of an effective response to the sceptic. Furthermore, phenomenal conservatism couldn’t form the general basis for foundationalism. (shrink)

_ Source: _Volume 94, Issue 4, pp 552 - 576 Two major arguments have been advanced for the claim that there is a transmission failure in G.E. Moore’s famous proof of an external world. The first argument, due to Crispin Wright, is based on an epistemological doctrine now known as ‘conservatism’. Proponents of the second argument, like Nicholas Silins, invoke probabilistic considerations, most important among them Bayes’ theorem. The aim of this essay is to defend Moore’s proof against these two (...) arguments. It is shown, first, that Wright’s argument founders because one of its premises, viz., conservatism, invites scepticism and must therefore be rejected. Then the probabilistic argument is challenged, not because its formal part is dubious, but rather on the grounds that it incorporates an unconvincing philosophical claim as an implicit premise. Finally, the two most promising objections to dogmatism—the negation of conservatism—are repudiated. (shrink)

This document presents a Gentzen-style deductive calculus and proves that it is complete with respect to a 3-valued semantics for a language with quantifiers. The semantics resembles the strong Kleene semantics with respect to conjunction, disjunction and negation. The completeness proof for the sentential fragment fills in the details of a proof sketched in Arnon Avron (2003). The extension to quantifiers is original but uses standard techniques.

I review recent work on Phenomenal Conservatism, the position introduced by Michael Huemer according to which if it seems that P to a subject S, in the absence of defeaters S has thereby some degree of justification for believing P.

Crispin Wright maintains that the architecture of perceptual justification is such that we can acquire justification for our perceptual beliefs only if we have antecedent justification for ruling out any sceptical alternative. Wright contends that this principle doesn’t elicit scepticism, for we are non-evidentially entitled to accept the negation of any sceptical alternative. Sebastiano Moruzzi has challenged Wright’s contention by arguing that since our non-evidential entitlements don’t remove the epistemic risk of our perceptual beliefs, they don’t actually enable us to (...) acquire justification for these beliefs. In this paper I show that Wright’s responses to Moruzzi are ineffective and that Moruzzi’s argument is validated by probabilistic reasoning. I also suggest that Wright cannot answer Moruzzi’s challenge without weakening the support available for his conception of the architecture of perceptual justification. (shrink)

ABSTRACTRational agents have consistent beliefs. Bayesianism is a theory of consistency for partial belief states. Rational agents also respond appropriately to experience. Dogmatism is a theory of how to respond appropriately to experience. Hence, Dogmatism and Bayesianism are theories of two very different aspects of rationality. It's surprising, then, that in recent years it has become common to claim that Dogmatism and Bayesianism are jointly inconsistent: how can two independently consistent theories with distinct subject matter be jointly inconsistent? In this (...) essay I argue that Bayesianism and Dogmatism are inconsistent only with the addition of a specific hypothesis about how the appropriate responses to perceptual experience are to be incorporated into the formal models of the Bayesian. That hypothesis isn't essential either to Bayesianism or to Dogmatism, and so Bayesianism and Dogmatism are jointly consistent. That leaves the matter of how experiences and credences are related, a... (shrink)

Perceptual experiences justify beliefs. A perceptual experience of a dog justifies the belief that there is a dog present. But there is much evidence that perceptual states can occur without being conscious, as in experiments involving masked priming. Do unconscious perceptual states provide justification as well? The answer depends on one’s theory of justification. While most varieties of externalism seem compatible with unconscious perceptual justification, several theories have recently afforded to consciousness a special role in perceptual justification. We argue that (...) such views face a dilemma: either consciousness should be understood in functionalist terms, in which case our best current theories of consciousness do not seem to imbue consciousness with any special epistemic features, or it should not, in which case it is mysterious why only conscious states are justificatory. We conclude that unconscious perceptual justification is quite plausible. (shrink)

I focus on a key argument for global external world scepticism resting on the underdetermination thesis: the argument according to which we cannot know any proposition about our physical environment because sense evidence for it equally justifies some sceptical alternative (e.g. the Cartesian demon conjecture). I contend that the underdetermination argument can go through only if the controversial thesis that conceivability is per se a source of evidence for metaphysical possibility is true. I also suggest a reason to doubt that (...) conceivability is per se a source of evidence for metaphysical possibility, and thus to doubt the underdetermination argument. (shrink)

Why should we believe that perceptions justify beliefs? One argument starts with the premise that sentences of the form “a looks F” may be used to justify conclusions of the form “a is F”. I will argue that this argument for the claim that perceptions justify beliefs founders on the following dilemma: Either “a looks F” does not report the content of a perception or, if it does, then it does not justify the conclusion “a is F”.

Internalists face the following challenge: what is it about an agent's internal states that explains why only these states can play whatever role the internalist thinks these states are playing? Internalists have frequently appealed to a special kind of epistemic access that we have to these states. But such claims have been challenged on both empirical and philosophical grounds. I will argue that internalists needn't appeal to any kind of privileged access claims. Rather, internalist conditions are important because of the (...) way in which we expect them to act as causal mediators between states of the world, on the one hand, and our beliefs and actions on the other. (shrink)

In previous work, I have suggested a doxastic account of perceptual experience according to which experiences form a kind of belief: Beliefs with what I have called “phenomenal” or “looks-content”. I have argued that this account can not only accommodate the intuitive reason providing role of experience, but also its justificatory role. I have also argued that, in general, construing experience and perceptual beliefs, i.e. the beliefs most directly based on experience, as having different contents best accounts for the defeasibility (...) of experiential reasons. In this paper, I shall have a closer look at the evidential or inferential relation between looks-propositions and the contents of perceptual beliefs and argue for a form of what I shall call “Pollockianism” about experiential reasons: such reasons are good unless defeated. Questions to be investigated include: Does the resulting picture of perceptual justification contain an externalist element? Is it compatible with Bayesianism? And how does it do with respect to problems that have been raised for other forms of Pollockianism such as dogmatism or phenomenal conservatism? (shrink)

Dogmatists claim that having a perceptual experience as of p can provide one with immediate and defeasible warrant to believe that p. A persistent complaint against this position is that it sanctions an intuitively illicit form of reasoning: bootstrapping. I argue that dogmatism has no such commitments. Dogmatism is compatible with a principle that disallows the final non-deductive inference in the bootstrapping procedure. However, some authors have maintained that such strategy is doomed to failure because earlier stages of in the (...) bootstrapping inference are already problematic. I argue that insofar as these inferences appear problematic, the dogmatist is not committed to sanctioning them. I conclude that the bootstrapping argument presents no significant objection to the claim that perceptual experiences can provide immediate and defeasible warrant to believe their contents. (shrink)

Roger White objects to interval-valued credence theories because they produce a counterintuitive “dilation” effect in a story he calls the Coin Game. We respond that results in the Coin Game were bound to be counterintuitive anyway, because the story involves an agent who learns a biconditional. Biconditional updates produce surprising results whether the credences involved are ranged or precise, so White's story is no counterexample to ranged credence theories.