Consider the skeptic about the external world. Let’s straightaway concede to such a skeptic that perception gives us no conclusive or certain knowledge about our surroundings. Our perceptual justification for beliefs about our surroundings is always defeasible—there are always possible improvements in our epistemic state which would no longer support those beliefs. Let’s also concede to the skeptic that it’s metaphysically possible for us to have all the experiences we’re now having while all those experiences are false. Some philosophers dispute (...) this, but I do not. The skeptic I want to consider goes beyond these familiar points to the much more radical conclusion that our perceptual experiences can’t give us any knowledge or even justification for believing that our surroundings are one way rather than another. (shrink)

Something about this argument sounds funny. As we’ll see, though, it takes some care to identify exactly what Moore has done wrong. Iwill assume that Moore knows premise (2) to be true. One could inquire into how he knows it, and whether that knowledge can be defeated; but Iwon’t. I’ll focus instead on what epistemic relations Moore has to premise (1) and to his conclusion (3). It may matter which epistemic relations we choose to consider. Some philosophers will diagnose Moore’s (...) argument using Contextualist machinery. They’ll say. (shrink)

[I]f you could know a priori that you are in a given mental state, and your being in that state conceptually or logically implies the existence of external objects, then you could know a priori that the external world exists. Since you obviously _can.

Psychological externalism is the thesis that the contents of many of a person's propositional mental states are determined in part by relations he bears to his natural and social environment. This thesis has recently been thrust into prominence in the philosophy of mind by a series of thought experiments due to Hilary Putnam and Tyler Burge. Externalism is a metaphysical thesis, but in this work I investigate its implications for the epistemology of the mental. I am primarily concerned with the (...) question whether externalism undermines the idea that a person typically knows the contents of her own thoughts, beliefs, and other propositional attitudes directly and authoritatively. I criticize arguments that have been advanced on behalf of a positive answer to this question, and argue that they rest on a faulty conception of the nature of first person authority, one which likens our access to our own minds to perception. An account of the basis of first person authority is sketched that locates our epistemic right to our self-ascriptions of propositional attitude not in our ability to discriminate among the various thought contents we might be thinking, but rather in our ability to express our thoughts, and to think with them in accordance with the norms of rationality. I consider also the question whether first person authority and externalism jointly make possible a refutation of certain forms of global skepticism, as has been famously argued by Putnam. I argue that Putnam's attempted refutation fails, because the crucial externalist claims that drive it are not knowable a priori. (shrink)

There are obvious benefits to be gained from the study of logic: heightened ability to express ideas clearly and concisely, increased skill in defining one's terms, enlarged capacity to formulate arguments rigorously and to analyze them critically. But the greatest benefit, in my judgment, is the recognition that reason can be applied in every aspect of human affairs.

Moore's proof of an external world is a piece of reasoning whose premises, in context, are true and warranted and whose conclusion is perfectly acceptable, and yet immediately seems flawed. I argue that neither Wright's nor Pryor's readings of the proof can explain this paradox. Rather, one must take the proof as responding to a sceptical challenge to our right to claim to have warrant for our ordinary empirical beliefs, either for any particular empirical belief we might have, or for (...) belief in the existence of an external world itself. I show how Wright's and Pryor's positions are of interest when taken in connection with Humean scepticism, but that it is only linking it with Cartesian scepticism which can explain why the proof strikes us as an obvious failure. (shrink)

I argue that its appearing to you that P does not provide justification for believing that P unless you have independent justification for the denial of skeptical alternatives – hypotheses incompatible with P but such that if they were true, it would still appear to you that P. Thus I challenge the popular view of ‘dogmatism,’ according to which for some contents P, you need only lack reason to suspect that skeptical alternatives are true, in order for an experience as (...) of P to justify belief that P. I pursue three lines of objection to dogmatism, having to do with probabilistic reasoning, considerations of future or hypothetically available justification, and epistemic circularity. I briefly sketch a fall-back position which avoids the problems raised. (shrink)

Hume argued that inductive inferences do not have rational justification. My aim is to reject Hume's argument. The discussion is partly motivated by an analogy with Carroll's Paradox, which concerns deductive inferences. A first radically externalist reply to Hume is that justified inductive inferences do not require the subject to know that nature is uniform, though the uniformity of nature is necessary condition for having the justification. But then the subject does not have reasons for believing what she believes. I (...) defend a moderate externalist account that seeks to partly accommodate that objection to the radical externalist proposal. It is based on an extension of Peacocke's theory of concepts: possession conditions for predicative concepts standing for natural properties include dispositions to project them to new cases in accordance with inductive inferential patterns. (shrink)

In the contemporary expanding literature on transmission failure and its connections with issues such as the Closure principle, the nature of perceptual warrant, Moore’s proof of an external world and the effectiveness of Humean scepticism, it has often been assumed that there is just one kind of it: the one made familiar by the writings of Crispin Wright and Martin Davies. Although it might be thought that one kind of failure is more than enough, Davies has recently challenged this view: (...) apparently, there are more ways in heaven and earth that warrant can fail to transmit across valid inference from one (set of) belief(s) to another, than have been dreamt of in philosophy so far. More specifically, Davies thinks that a second kind of transmission failure has to be countenanced. He connects each kind of failure of transmission of warrant with two different kinds of epistemic project, respectively, and with the exploration of whether the current dispute between conservatives such as Wright, and liberals such as Jim Pryor, on the nature of perceptual warrant, would have a bearing on them. I point out why Davies’s second kind of transmission failure is indeed no such thing. I then move on to canvass another kind of transmission failure, different from the one studied by both Wright and Davies, and dependent on an alternative conception of the structure of empirical warrants, which I dub “moderatism”. I then consider how this alternative notion of transmission failure fares with respect to Moore’s proof, its relationship with Wright’s kind of transmission failure and with the Closure principle. In closing, I defend it from criticisms that can be elicited from Pryor’s recent work. (shrink)

He then argues that (1), (2) and (3) constitute an inconsistent triad as follows (1991, p. 15): Suppose (1) that Oscar knows a priori that he is thinking that water is wet. Then by (2), Oscar can simply deduce E, using premisses that are knowable a priori, including the premiss that he is thinking that water is wet. Since Oscar can deduce E from premisses that are knowable a priori, Oscar can know E itself a priori. But this contradicts (3), (...) the assumption that E cannot be known a priori. Hence (1), (2), and (3) are inconsistent. McKinsey’s conclusion is that ‘anti-individualism is inconsistent with privileged access’ (ibid.). (shrink)

Desarrollo varias hipótesis sobre los propósitos de la argumentación racional, parcialmente inspiradas en el análisis de Jackson sobre el concepto de petitio principii. Destaco como especialmente relevante entre tales propósitos la referencia a los potenciales destinatarios de una argumentación. Ilustro la discusión con un caso concreto: el argumento elaborado por Putnam para demostrar que no somos cerebros en una cubeta. Presento una versión de ese argumento y lo defiendo frente a una posible crítica que lo acusa de prejuzgar la cuestión.I (...) work out some hypothesis on the purposes of rational arguing, partly inspired by Jackson’s analysis of the concept of petitio principii. It is especially relevant among such purposes the reference to the potential intended addressee of an argument. The discussion is illustrated with a concrete example: Putnam’s proofthat we are not brains in a vat. I present a version of Putnam’s proof and defend it from a possible criticism which accuses it of begging the question. (shrink)

In the recent literature on Moore's Proof of an external world, it has emerged that different diagnoses of the argument's failure are prima facie defensible. As a result, there is a sense that the appropriateness of the different verdicts on it may depend on variation in the kinds of context in which the argument is taken to be a move, with different characteristic aims. In this spirit, Martin Davies has recently explored the use of the argument within two different epistemic (...) projects called respectively ‘deciding what to believe’ and ‘settling the question’. Depending on which project is in hand, according to Davies, the diagnoses of its failure—if indeed it fails—will differ. I believe that, by introducing the idea that the effectiveness of a valid argument may be epistemic project-relative, Davies has pointed the way to an important reorientation of the debates about Moore's Proof. But I wish to take issue with much of the detail of his proposals. I argue that Davies's characterization of his two projects is misleading (§1), and his account of their distinction defective (§2). I then canvass some suggestions about how it may be improved upon and about how further relevant kinds of epistemic projects in which Moore's argument may be taken to be a move can be characterized, bringing out how each of these projects impinges differently on the issue of the Proof's failure and of its diagnosis (§§3 and 4). In conclusion (§5) I offer an overview of the resulting terrain. (shrink)

A number of epistemologists have recently concluded that a piece of reasoning may be epistemically permissible even when it is impossible for the reasoning subject to present her reasoning as an argument without begging the question. I agree with these epistemologists, but argue that none has sufficiently divorced the notion of begging the question from epistemic notions. I present a proposal for a characterization of begging the question in purely pragmatic terms.