RRecently, much work has been done on G.E. Moore’s proof of an external world with the aim of diagnosing just where the Proof ‘goes wrong’. In the mainstream literature, the most widely discussed debate on this score stands between those who defend competing accounts of perceptual warrant known as dogmatism and conservativism. Each account implies a different verdict on Moore’s Proof, though both share a commitment to supposing that an examination of premise-conclusion dependence relations will sufficiently reveal what’s wrong with (...) the Proof. Parallel to this debate on Moore stands perhaps an equally interesting debate within which the Proof is critiqued as it stands in the context of the skeptical debate. On this score, Michael Fara and Ernest Sosa have weighed in with a markedly different take on Moore’s anti-skeptical ambitions and on the nature of skeptical challenges more generally. The aim of this paper will be to critically evaluate these two very distinct strands of recent work on Moore’s Proof. Part I of the paper will focus on the mainstream debate, and in Part II of the paper, I’ll focus on the parallel debate about skepticism. My critical discussion will be aimed throughout at showing how the various proposals I’ve taken as representative of these two parallel debates surrounding Moore’s Proof ultimately fall short—each for different reasons—of what a satisfactory diagnosis of the Proof would require. (shrink)

The current standard interpretation of Moore’s proof assumes Moore offers a solution to Kant’s famously posed problem of an external world, which Moore quotes at the start of his 1939 lecture “Proof of an External World.” As a solution to Kant’s problem, Moore’s proof fails utterly. Similarly, a second received interpretation imputes an aim of refuting metaphysical idealism that Moore’s proof does not at all achieve. This study departs from the received interpretations to credit Moore’s stated aim for the proof (...) Moore performed in his 1939 lecture that is to impose a counter-example to an explicitly stated presupposition of Kant’s famously posed problem of an external world. The outcome would therefore subvert Kant’s problem. There is not, however, any rival external world problem that Moore commends in place of Kant’s problem. (shrink)

Duncan Pritchard recently proposed a Wittgensteinian solution to closure-based skepticism. According to Wittgenstein, all epistemic systems assume certain truths. The notions that we are not disembodied brains, that the Earth has existed for a long time and that one’s name is such-and-such all function as “hinge commitments.” Pritchard views a hinge commitment as a positive propositional attitude that is not a belief. Because closure principles concern only knowledge-apt beliefs, they do not apply to hinge commitments. Thus, from the fact that (...) a subject knows that he is sitting in a room, and the fact that the subject’s sitting in a room entails his bodily existence, it does not follow that the subject also knows that he is not an envatted brain. This paper rejects Pritchard’s non-belief reading of hinge commitments. I start by showing that the non-belief reading fails to solve the skeptical paradox because the reasons that Pritchard uses to support the non-belief reading do not exempt hinge propositions from closure principles. I then proceed to argue that the non-belief reading is false as it claims that hinge commitments, unlike ordinary beliefs, are rationally unresponsive—with the help of a scenario in which a subject’s experience is internally chaotic, we can safely conclude that the hinge commitment that one is not systematically mistaken about the world is equally responsive to one’s evidential situations. (shrink)

I defend an account of Moore's conception of Common Sense—as it figures in "A Defence of Common Sense"—according to which it is based in a vision of the community of human beings as bound and unified by a settled common understanding of the meaning of our words and statements. This, for Moore, is our inalienable starting point in philosophy. When Moore invokes Common Sense against idealist (and skeptical) philosophers, he is reminding them that they too are bound by this common (...) understanding, which cannot just be left behind as they confusedly believe. On Moore's conception, Common Sense becomes nothing other than the affirmation that there is such a common understanding—that there is Common Sense—which yields a specific body of Common Sense knowledge. This yields a more principled account of Common Sense than a mere tallying of what contingently happens to be believed (or known) by all. (shrink)

I argue that coherence is truth-conducive in that coherence implies an increase in the probability of truth. Central to my argument is a certain principle for transitivity in probabilistic support. I then address a question concerning the truth-conduciveness of coherence as it relates to (something else I argue for) the truth-conduciveness of consistency, and consider how the truth-conduciveness of coherence bears on coherentist theories of justification.

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that (...) the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s “proof” of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive. (shrink)

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that (...) the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s ‘‘proof’’ of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive. (shrink)

Even if our justified beliefs are closed under known entailment, there may still be instances of transmission failure. Transmission failure occurs when P entails Q, but a subject cannot acquire a justified belief that Q by deducing it from P. Paradigm cases of transmission failure involve inferences from mundane beliefs (e.g., that the wall in front of you is red) to the denials of skeptical hypotheses relative to those beliefs (e.g., that the wall in front of you is not white (...) and lit by red lights). According to the Bayesian explanation, transmission failure occurs when (i) the subject’s belief that P is based on E, and (ii) P(Q|E) P(Q). No modifications of the Bayesian explanation are capable of accommodating such cases, so the explanation must be rejected as inadequate. Alternative explanations employing simple subjunctive conditionals are fully capable of capturing all of the paradigm cases, as well as those missed by the Bayesian explanation. (shrink)

Contemporary debates concerning warrant transmission take for granted this thesis: when warrant transmission fails the argument fails. I challenge this thesis. An argument with conclusion C, addressed to subject S, can be cogent in the sense that recognition that the premises entail (or make highly likely) C can rationally foster in S the belief in C, without the warrant for C necessarily being gained (or reinforced) by such recognition. A key idea is to accept that some arguments should be understood (...) in a way that involves the abandonment of two characteristic idealizations imposed on rational thinkers by Bayesian modelling. (shrink)

A common view about Moore’s Proof of an External World is that the argument fails because anyone who had doubts about its conclusion could not use the argument to rationally overcome those doubts. I agree that Moore’s Proof is—in that sense—dialectically ineffective at convincing an opponent or a doubter, but I defend that the argument (even when individuated taking into consideration the purpose of Moore’s arguing and, consequently, the preferred addressee of the Proof) does not fail. The key to my (...) defence is to conceive the Proof as addressed to subjects with a different epistemic condition. To sustain this view I formulate some hypothesis about the common general purpose of arguing and I defend that it can be fulfilled even when the addressee of an argument is not someone who disbelieves or doubts its conclusion. (shrink)

We develop a reading of Moore’s “Proof of an External World” that emphasizes the connections between this paper and Moore’s earlier concerns and strategies. Our reading has the benefit of explaining why the claims that Moore advances in “Proof of an External World” would have been of interest to him, and avoids attributing to him arguments that are either trivial or wildly unsuccessful. Part of the evidence for our view comes from unpublished drafts which, we believe, contain important clues concerning (...) Moore’s aims and intent. While our approach to PEW may be classified alongside other broadly "metaphysical" readings, we believe that a proper recognition of the continuity in Moore’s philosophical concerns and strategies across his philosophical career shows that the customary distinction between "epistemological" and "metaphysical" interpretative approaches to PEW is at best superficial. (shrink)

In this paper, I present and criticize a number of influential contemporary anti-skeptical strategies inspired by G.E. Moore’s “proof of an external world”. I argue that these accounts cannot represent a valid response to skeptical worries. Furthermore, drawing on Wittgenstein’s criticisms of Moore, I argue that Radical skeptical hypotheses should be considered nonsensical combinations of signs, excluded from our epistemic practices.

Inference to the best explanation—or, IBE—tells us to infer from the available evidence to the hypothesis which would, if correct, best explain that evidence. As Peter Lipton puts it, the core idea driving IBE is that explanatory considerations are a guide to inference. But what is the epistemic status of IBE, itself? One issue of contemporary interest is whether it is possible to provide a justification for IBE itself which is non- objectionably circular. We aim to carve out some new (...) space in this debate. In particular, we suggest that the matter of whether a given rule-circular argument is objectionably circular itself depends crucially on some subtle distinctions which have been made in the recent literature on perceptual warrant. By bringing these debates together, a principled reason emerges for why some kinds of rule-circular justifications for IBE are considerably less objectionable than others. (shrink)

G.E. Moore’s writings on external world skepticism show us, in broad outline, how to dispense with external world skepticism in a way that is satisfying, intellectually responsible, and yet avoids engaging in constructive epistemological theory-building altogether. His work thus reveals something very important about the relation between epistemology and ordinary life, and also about what it would take to reach a satisfying resolution of certain sorts of perennial philosophical problems.