This paper evaluates Putnam’s argument in the first chapter of Reason, Truth and History, for the claim that we can know that we are not brains in a vat (of a certain sort). A widespread response to Putnam’s argument has been that if it were successful not only the world but the meanings of our words (and consequently our thoughts) would be beyond the pale of knowledge, because a causal theory of reference is not compatible with our having knowledge of (...) the meanings of our words. I argue that this is not so. I argue also, however, that given how Putnam argues (here) for the causal theory of reference, he cannot after all escape this consequence. (shrink)

Recently we proposed "quantum language" (or, the linguistic Copenhagen interpretation of quantum mechanics"), which was not only characterized as the metaphysical and linguistic turn of quantum mechanics but also the linguistic turn of Descartes=Kant epistemology. We believe that quantum language is the language to describe science, which is the final goal of dualistic idealism. Hence there is a reason to want to clarify, from the quantum linguistic point of view, the following problems: "brain in a vat argument", "the Cogito (...) proposition", "five-minute hypothesis", "only the present exists", "Copernican revolution", "McTaggart's paradox", and so on. In this paper, these will be discussed and clarified in quantum language. That is, these are not in quantum language. Also we emphasize that Leibniz's relationalism in Leibniz-Clarke correspondence is regarded as one of the most important parts of the linguistic Copenhagen interpretation of quantum mechanics. This paper is the revised version of the paper: Open Journal of Philosophy, 2018 Vol.8, No.5, 466-480). (shrink)

Let’s consider the skeptical example of the brain in a vat. It has been pointed out by Crispin Wright (1994) that Putnam's argument does not affect certain cases such as my brain being removed from my skull by a mad scientist and hooked up to a computer. Since Putnam's argument falls flat at least in cases where the brain is first removed from a human body and then hooked up to a computer, I consider the skeptical aspects (...) of the brain-in-a-vat thought experiment below. Let’s consider the following hypotheses: C “I’m a brain in a vat” EC “I’m not a brain in a vat”. It is argued by skeptics that it cannot be proven that we are not brains in a vat. If we assume the skeptical thesis according to which it is impossible to prove that we are not brains in a vat, i.e. there is the impossibility of falsifying C, then the truthfulness of EC implies that both C and EC can not be falsified. On the other hand, the truthfulness of C does not imply the unfalsifiability of EC: for example, the mad scientist mentioned above could decide (perhaps for a sadistic pleasure) to inform us and prove to us that we are brains in a vat; in the latter case the EC hypothesis would be falsified. The truthfulness of EC implies the unfalsifiability of both EC and C. By contrast, the truthfulness of C does not imply the unfalsifiability of EC. The current evidence is that both C and EC are not falsified: the hypothesis EC necessarily implies that both EC and C result not falsified; the hypothesis C does not necessarily imply that both C and EC result not falsified And so, it is more rational to bet on EC rather than on C. (shrink)

Skeptical hypotheses such as the brain-in-a-vat hypothesis provide extremely poor explanations for our sensory experiences. Because these scenarios accommodate virtually any possible set of evidence, the probability of any given set of evidence on the skeptical scenario is near zero; hence, on Bayesian grounds, the scenario is not well supported by the evidence. By contrast, serious theories make reasonably specific predictions about the evidence and are then well supported when these predictions are satisfied.

David Chalmers has recently developed a novel strategy of refuting external world skepticism, one he dubs the structuralist solution. In this paper, I make three primary claims: First, structuralism does not vindicate knowledge of other minds, even if it is combined with a functionalist approach to the metaphysics of minds. Second, because structuralism does not vindicate knowledge of other minds, the structuralist solution vindicates far less worldly knowledge than we would hope for from a solution to skepticism. Third, these results (...) suggest that the problem of external world skepticism should perhaps be construed as two different problems, since the problem might turn out to require two substantively different solutions, one for knowledge of the kind that is not dependent on other minds and one for knowledge that is. (shrink)

Contemporary discussions of epistemological skepticism - the view that we do not and cannot know anything about the world around us - focus very much on a certain kind of skeptical argument involving a skeptical scenario (a situation familiar from Descartes’ First Meditation). According to the argument, knowing some ordinary proposition about the world (one we usually take ourselves to know) requires knowing we are not in some such skeptical scenario SK; however, since we cannot know that we are not (...) in SK we also cannot know any ordinary proposition. One of the most prominent skeptical scenarios is the brain-in-the-vat-scenario: An evil scientist has operated on an unsuspecting subject, removed the subject’s brain and put it in a vat where it is kept functioning and is connected to some computer which feeds the brain the illusion that everything is “normal”. This paper looks at one aspect of this scenario after another – envatment, disembodiment, weird cognitive processes, lack of the right kind of epistemic standing, and systematic deception. The conclusion is that none of these aspects (in isolation or in combination) is of any relevance for a would-be skeptical argument; the brain-in-the-vat-scenario is irrelevant to and useless for skeptical purposes. Given that related scenarios (e.g., involving evil demons) share the defects of the brain-in-the-vat-scenario, the skeptic should not put any hopes on Cartesian topoi. (shrink)

In this chapter, Pautz raises a puzzle about spatial experience for phenomenal internalists like Ned Block. If an accidental, lifelong brain-in-the-void (BIV) should have all the same experiences as you, it would have an experience as of items having various shapes, and be able to acquire concepts of those shapes, despite being cut off from real things with the shapes. Internalists cannot explain this by saying that BIV is presented with Peacocke-style visual field regions having various shapes, because these (...) would have to be non-physical sense data. They might instead explain this by saying that BIV “phenomenally represents” various shape properties. But since BIV lacks any interesting physical relations to shapes, this would imply that phenomenally representation is an irreducible relation. (shrink)

Hilary Putnam’s BIV argument first occurred to him when ‘thinking about a theorem in modern logic, the “Skolem–Löwenheim Theorem”’ (Putnam 1981: 7). One of my aims in this paper is to explore the connection between the argument and the Theorem. But I also want to draw some further connections. In particular, I think that Putnam’s BIV argument provides us with an impressively versatile template for dealing with sceptical challenges. Indeed, this template allows us to unify some of Putnam’s most enduring (...) contributions to the realism/antirealism debate: his discussions of brains-in-vats, of Skolem’s Paradox, and of permutations. In all three cases, we have an argument which does not merely defeat the sceptic; it also shows us that we must reject some prima facie plausible philosophical picture. (shrink)

According to epistemic internalism, the only facts that determine the justificational status of a belief are facts about the subject’s own mental states, like beliefs and experiences. Externalists instead hold that certain external facts, such as facts about the world or the reliability of a belief-producing mechanism, affect a belief’s justificational status. Some internalists argue that considerations about evil demon victims and brains in vats provide excellent reason to reject externalism: because these subjects are placed in epistemically unfavorable settings, externalism (...) seems unable to account for the strong intuition that these subjects’ beliefs are nonetheless justified. I think these considerations do not at all help the internalist cause. I argue that by appealing to the anti-individualistic nature of perception, it can be shown that skeptical scenarios provide no reason to prefer internalism to externalism. (shrink)

Intuitively, we can conceive of the existence of a conscious state as a pure activity that does not necessarily require a body (or even a brain). This idea has found new support in certain recent theories that present the possibility of a totally disconnected and disembodied consciousness. Against this hypothesis, I argue that human experience is intrinsically embodied and embedded, though in a specific way. Using Sartre’s phenomenology of the body, I first analyze the concept of consciousness as intentionality (...) and a world-disclosing activity, thus explaining how conscious activity can only be expressed through a body that is spatiotemporally related to the world. Then, I argue that bodily consciousness does not necessarily imply the actual presence of an anatomical body but, rather, a process of spatialization and temporalization (hodological space and temporal synthesis) through the “spatiotemporal body”. Finally, I test my thesis by critiquing some cases of apparent disembodied/disconnected consciousness, i.e., dreams, out-of-body experiences, and the brain-in-a-vat scenario. (shrink)

The “brain in a vat” thought experiment is presented and refuted by appeal to the intuitiveness of what the author informally calls “the eye for an eye principle”, namely: Conscious mental states typically involved in sensory processes can conceivably successfully be brought about by direct stimulation of the brain, and in all such cases the utilized stimulus field will be in the relevant sense equivalent to the actual PNS or part of it thereof. In the second section, four (...) classic problems of Functionalism are given novel solutions based on the inclusion of peripheral nervous processes as constituents of mental states: The mad pain problem, the problem of pseudo-normal vision, the China-brain problem, and the triviality problem. (shrink)

Hilary Putnam has famously argued that “we are brains in a vat” is necessarily false. The argument assumes content externalism (also known as semantic externalism and anti-individualism), that is, the view that the individuation conditions of mental content depend, in part, on external or relational properties of the subject’s environment. Recently content externalism has given rise to the hypothesis of the extended mind, whereby mental states are not only externally individuated but also externally located states. This chapter argues that when (...) content externalism is combined with the extended mind hypothesis it is robbed of its anti-skeptical power. Given the extended mind hypothesis, the supercomputer and the envatted brain can be regarded as aspects of the extended mind of the evil scientist. On this view, the thought contents of the coupled brain–computer–scientist system do not differ from those of a normal human. But without a difference in thought contents Putnam’s anti-skeptical argument crumbles. (shrink)

Articolo divulgativo pubblicato su l'Indiscreto il 23 ottobre 2024. Rappresenta il secondo capitolo di un testo che cercherà di fare una rapida panoramica su otto settori della filosofia analitica. Si presentano le teorie epistemiciste e si analizzano le più celebri argomentazioni connesse: il paradosso di Fitch, la Terra Gemella, il Brain in a Vat, il Model-Theoretic Argument Against Realism. Infine, si accenna rapidamente al deflazionismo e ad un possibile modello pluralista.

Can we conceive of a mind without body? Does, for example, the idea of the soul's immortality make sense? Certain versions of materialism deny such questions; I shall try to prove that these versions of materialism cannot be right. They fail because they cannot account for the mental vocabulary from the language of brains in the vat. Envatted expressions such as "I think", "I believe", etc., do not have to be reinterpreted when we translate them to our language; they are (...) semantically stable. By contrast, physical expressions from the vat language are semantically instable; due to Putnam's externalism they cannot be transported to our language without change. This contrast opens the way to a new understanding of what the immortality of the soul might be like: A brain in a vat (and its mental life) might survive what the brain calls "my physical body's death". (shrink)

This essay is concerned with solipsism, understood as the extreme sceptical view that I have no knowledge except of my subjective state. A less rough formulation of the view is mooted, inspired by a Quinean combination of naturalism and empiricism. An objection to the resultant position is then considered, based on Putnam’s argument that we are not brains in vats. This objection is first outlined, then pitted against a series of counter-objections. Eventually it is endorsed, but only at the price (...) of exposing the formulation of solipsism in question as not, after all, a satisfactory formulation. This leads to further speculation about the status of solipsism itself. Two of the possibilities that are considered are, firstly, that it is incoherent and, secondly, that it is inexpressible. (shrink)

In this paper we will explore how the action of signs underlying all human experience precludes the possibility that we are being systematically deceived in our perception of reality. The simulation hypothesis, as well as similarly motivated skeptical scenarios, such as the brain-in-a-vat hypothesis and Descartes’ evil demon thought experiment, wrongly presuppose a modern, dualistic theory of knowledge, as well as a neuroreductionist model of sensation. However, we will see how the action of signs in human cognition presupposes the (...) existence of a relational mode of being, namely, esse intentionale (“intentional being”), which is immaterial and incapable of subjection to technological manipulation. Furthermore, sensation, the origin of all human knowledge, and ens primum cognitum (“being as first known”), the condition of all human knowledge, both defy materialistic explanations. The doctrine of signs, as masterfully articulated by John Poinsot (John of St. Thomas), recognizes the triadic nature of relations underlying the full range of human experience. A proper understanding of the relationship between mind and world, as well as a recognition of the mistaken presuppositions underlying much of modern philosophy, will help to disillusion those who are convinced by the simulation hypothesis and other similarly motivated skeptical scenarios. (shrink)

Based on the brain in a vat thought experiment, skeptics argue that we cannot have certain knowledge. At the same time, we do have the intuition that we know some things with certainty. A way to justify this intuition is given by semantic contextualists who argue that the word “knows” is context sensitive. However, many have objected to the intelligibility of this claim. In response, another approach called “moderate pragmatic contextualism” was invoked, which claims that “knows” itself is not (...) context sensitive, but knowledge assertions are. I show, however, that to refute skepticism, moderate pragmatic contextualism rests on unjustified and implausible assumptions as well. Since no form of contextualism works as a response to skepticism, I argue that we should simply accept skepticism. However, I argue that skepticism is not a problem because skeptic pragmatic contextualism can offer a plausible explanation of why we have the intuition that our ordinary knowledge claims are true, even though they are not. I conclude that skeptic pragmatic contextualism offers the most plausible response to the brain in a vat thought experiment. (shrink)

If it works, I can use Putnam’s vat argument to show that I have not always been a brain-in-a-vat. It is widely thought that the vat argument is of no use against closure scepticism – that is, scepticism motivated by arguments that appeal to a closure principle. This is because, even if I can use the vat argument to show that I have not always been a BIV, I cannot use it to show that I was not recently envatted, (...) and it is thought that the claim that I am not justified in thinking that I was not recently envatted is all that the closure sceptic requires. In this paper I first argue that scenarios in which I have been recently envatted are inadequate for the sceptic’s purposes, and so the standard argument that the vat argument is of no use against closure scepticism fails. I then argue that it is not possible to revise the standard argument to meet my objection. I conclude that, if it works, I can use the vat argument as a defence against closure scepticism. (shrink)

Nick Bostrom’s recently patched ‘‘simulation argument’’ (Bostrom in Philos Q 53:243–255, 2003; Bos- trom and Kulczycki in Analysis 71:54–61, 2011) purports to demonstrate the probability that we ‘‘live’’ now in an ‘‘ancestor simulation’’—that is as a simulation of a period prior to that in which a civilization more advanced than our own—‘‘post-human’’—becomes able to simulate such a state of affairs as ours. As such simulations under consid- eration resemble ‘‘brains in vats’’ (BIVs) and may appear open to similar objections, the (...) paper begins by reviewing objections to BIV-type proposals, specifically those due a presumed mad envatter. In counter example, we explore the motivating rationale behind current work in the development of psychologically realistic social simula- tions. Further concerns about rendering human cognition in a computational medium are confronted through review of current dynamic systems models of cognitive agency. In these models, aspects of the human condition are repro- duced that may in other forms be considered incomputable, i.e., political voice, predictive planning, and consciousness. The paper then argues that simulations afford a unique potential to secure a post-human future, and may be nec- essary for a pre-post-human civilization like our own to achieve and to maintain a post-human situation. Long-s- tanding philosophical interest in tools of this nature for Aristotle’s ‘‘statesman’’ and more recently for E.O. Wilson in the 1990s is observed. Self-extinction-level threats from State and individual levels of organization are compared, and a likely dependence on large-scale psychologically realistic simulations to get past self-extinction-level threats is projected. In the end, Bostrom’s basic argument for the conviction that we exist now in a simulation is reaffirmed. (shrink)

A naturalistic theory of intentionality is proposed that differs from previous evolutionary and tracking theories. Full-blown intentionality is constructed through a series of evolvable refinements. A first, minimal version of intentionality originates from a conjectured internal process that estimates an organism’s own fitness and that continually modifies the organism. This process produces the directedness of intentionality. The internal estimator can be parsed into intentional components that point to components of the process that produces fitness. It is argued that such intentional (...) components can point to mistaken or non-existing entities. Different Fregian senses of the same reference correspond to different components that have different roles in the estimator. Intentional components that point to intentional components in other organisms produce directedness towards semi-abstract entities. Finally, adding a general, population-wide means of communication enables intentional components that point to fully abstract entities. Intentionality thus naturalized has all of its expected properties: being directed; potentially making errors; possibly pointing to non-existent, abstract, or rigid entities; capable of pointing many-to-one and one-to-many; distinguishing sense and reference; having perspective and grain; and having determinate content. Several examples, such as ‘swampman’ and ‘brain-in-a-vat’, illustrate how the theory can be applied. (shrink)

Putnam’s vat argument is intended to show that I am not a permanently envatted brain. The argument holds promise as a response to vat scepticism, which depends on the claim that I do not know that I am not a permanently envatted brain. However, there is a widespread idea that the vat argument cannot fulfil this promise, because to employ the argument as a response to vat scepticism I would have to make assumptions about the content of the (...) premises and/or conclusion of the argument that beg the question against the sceptic. In this paper, I show that this idea is mistaken. (shrink)

Most people will agree that if my brain were made to have within it precisely the same pattern of activity that is in it now but through artificial means, as in its being fed all its stimulation through electrodes as it sits in a vat, an experience would result for me that would be subjectively indistinguishable from that I am now having. In ‘The Story of a Brain’ I ask whether the same subjective experience would be maintained in (...) variations like these: The hemispheres are in different vats but interacting with each other through radio transmission. Smaller chunks - and eventually the individual neurons - are interacting in this way. The hemispheres or the smaller chunks undergo internally the same pattern of activity but without interacting with each other. (shrink)

Imagine two urns, each with a thousand beads - in one all the beads are blue while in the other only one of the thousand is blue. If one of these urns is pushed forward (based on the toss of a fair coin) and the single bead then randomly drawn from it is blue, we must infer that it is a thousand times more probable that the urn pushed forward is the purely blue one. The hypothesis that this was instead (...) the urn with only one blue bead would require that the occurrence of the evidence, the blue bead being drawn, was something improbable - and it is improbable that something improbable is what has occurred. Next consider an example of only one urn with no prior description. By the same reasoning as above, if all the first beads randomly drawn are blue, it is becoming more and more probable that the beads in the urn are generally blue. (Otherwise something improbable would be happening in another colour not appearing; and what’s improbable is improbable.) It is therefore probable also that the next bead drawn will be blue. This is induction. As Hume would have said, we could not know a priori, given this evidence, that the next bead will be blue. But, as he overlooked, we can know a priori, given this evidence, that it is probable that the next bead will be blue. In neither urn example has the belief regarding the beads been formed as a Humean habit of expectation after many observations of beads. (In the first case there is only one observation. The second could be modified to have all the beads drawn out at once.) Rather the belief is a product of a priori reasoning about probability. Next imagine that a coin has been tossed a thousand times and landed heads every time. There was a fair and a loaded coin. According to the same reasoning, it is overwhelmingly more probable that the coin used was the loaded one. For that the fair coin had so landed is most improbable. The hypothesis that there is no external world makes the orderliness in my current experience improbable - much like getting all heads with a fair coin. (Uncaused sensation would most probably be chaotic.) The most probable hypothesis is that of things like those we believe in causing this orderliness - as the coin’s being loaded would have caused all heads. The hypothesis that my experience has been made to take this pattern by a Cartesian malicious demon or by scientists controlling my brain in a vat can only falsely seem to make the character of the experience probable by sneaking in an inherently improbable ad hoc specification that this sort of pattern of experience was that which they were aiming at producing - like an ad hoc specification that the fair coin was one that by chance landed heads all thousand times. We may thus reject such hypotheses as improbable. So this is the problem of induction solved and scepticism answered through a priori reasoning. (shrink)

Let us imagine an ideal ethical agent, i.e., an agent who (i) holds a certain ethical theory, (ii) has all factual knowledge needed for determining which action among those open to her is right and which is wrong, according to her theory, and who (iii) is ideally motivated to really do whatever her ethical theory demands her to do. If we grant that the notions of omniscience and ideal motivation both make sense, we may ask: Could there possibly be an (...) ideal utilitarian, that is, an ideal ethical agent whose ethical theory says that our only moral obligation consists in maximizing utility? I claim that an ideal agent cannot be utilitarian. My reasoning against ideal utilitarianism will parallel Putnam's famous argument against the brains in a vat. Putnam argues that an envatted brain cannot describe its own situation because its words do not refer to brains and vats; I argue that an ideal utilitarian cannot entertain or communicate the beliefs necessary to being a utilitarian. (shrink)

I’m going to argue for a set of restricted skeptical results: roughly put, we don’t know that fire engines are red, we don’t know that we sometimes have pains in our lower backs, we don’t know that John Rawls was kind, and we don’t even know that we believe any of those truths. However, people unfamiliar with philosophy and cognitive science do know all those things. The skeptical argument is traditional in form: here’s a skeptical hypothesis; you can’t epistemically neutralize (...) it, you have to be able to neutralize it to know P; so you don’t know P. But the skeptical hypotheses I plug into it are “real, live” scientific-philosophical hypotheses often thought to be actually true, unlike any of the outrageous traditional skeptical hypotheses (e.g., ‘You’re a brain in a vat’). So I call the resulting skepticism Live Skepticism. Notably, the Live Skeptic’s argument goes through even if we adopt the clever anti-skeptical fixes thought up in recent years such as reliabilism, relevant alternatives theory, contextualism, and the rejection of epistemic closure. Furthermore, the scope of Live Skepticism is bizarre: although we don’t know the simple facts noted above, many of us do know that there are black holes and other amazing facts. (shrink)

Wittgenstein once wrote, “a wheel that can be turned though nothing else moves with it, is not part of the mechanism,” and Nyberg’s explanation as to why Hilary Putnam’s answer to the question of whether we might intelligibly suppose ourselves to be “brains in a vat” is wrong takes us, by way of Wittgenstein’s statement, to the intersection of metaphysics and epistemology, i.e., to the very cornerstone of western philosophy, where we find, waiting for us, the absolute I of solipsism. (...) Yet, it is the solipsistic I which in its articulation most obviously violates the private language argument’s stricture against criterionless reference, though the solipsist has available a reply of sorts – the reply of silence, a complete silence which shrouds equally the blank slates of absolute solipsism and pure realism. Through silence, the I of solipsism becomes the eye of realism and, no longer visible even to itself, vanishes from the realm of analytic discourse, only to be reborn at the correspondent point of each successive incarnation of the paradigm. Other methods of philosophy must, thus, be adopted if we are ever to escape the analytic paradigm’s cyclic limits. It is here, at the point where analysis alone can carry us no further, that “Zen” transitions from an unusually-structured but still traditional philosophic essay into something else entirely, with the incorporation into its closing pages of 15 poetic pieces, each drawn from Nyberg’s 100, a longer text of philosophical poetry which takes up where “Zen” leaves off. [email protected] Iowa City, Iowa/Palo Alto, California/New York, New York/Los Angeles, California/Rapid City, South Dakota June 1982-January 2020 . (shrink)

In recent work, Sosa proposes a comprehensive account of epistemic value based on an axiology for attempts. According to this axiology, an attempt is better if it succeeds, better still if it is apt (i.e., succeeds through competence), and best if it is fully apt, (i.e., guided to aptness by apt beliefs that it would be apt). Beliefs are understood as attempts aiming at the truth. Thus, a belief is better if true, better still if apt, and best if fully (...) apt. I raise a Kantian obstacle for Sosa’s account, arguing that the quality or worth of an attempt is independent of whether it succeeds. In particular, an attempt can be fully worthy despite being a failure. I then consider whether Sosa’s competence-theoretic framework provides the resources for an axiology of attempts that does not place so much weight on success. I discuss the most promising candidate, an axiology grounded in the competence of attempts, or what Sosa calls adroitness. An adroit attempt may fail. I raise doubts about whether an adroitness-based axiology can provide a plausible explanation of the worthiness of subjects’ beliefs in epistemically unfortunate situations, such as the beliefs of the brain in a vat. I conclude by speculating that the notion of a belief’s fit with what the subject has to go on, a notion missing from Sosa’s competence-theoretic framework, is crucial to explaining epistemic worth. (shrink)

The skeptic argues that we cannot have any external world knowledge because we cannot know that we are not brains in a vat. The intuitive appeal of this skeptical argument is essentially based on the comprehensibility of the process of skeptical doubting, where we focus our attention on our experiences and experience-based beliefs and raise questions about the sources of these experiences. I propose that skeptical doubting is an instance of a mental attitude that contemporary psychology characterizes as mindfulness. I (...) suggest that mindful self-reflection is not a single phenomenon but rather a cluster of related phenomena that are characterized by an epistemic gap of one kind or the other. I conclude that the persuasiveness of the skeptical argument is based on undergoing the mental process of mindful self-reflection. The undesired skeptical results are gained by overemphasizing the epistemic force of this mental attitude. (shrink)

Hillary Putnam has famously argued that we can know that we are not brains in a vat because the hypothesis that we are is self-refuting. While Putnam's argument has generated interest primarily as a novel response to skepticism, his original use of the brain in a vat scenario was meant to illustrate a point about the "mind/world relationship." In particular, he intended it to be part of an argument against the coherence of metaphysical realism, and thus to be part (...) of a defense of his conception of truth as idealized rational acceptability. Putnam's conclusions about the scenario are, however, actually out of line with central and plausible aspects of his own account of the relationship between our minds and the world. Reflections on semantics give us no compelling reason to suppose that claims like "I am a brain in a vat" could not turn out to be true. (shrink)

Are we perhaps in the "matrix", or anyway, victims of perfect and permanent computer simulation? No. The most convincing—and shortest—version of Putnam's argument against the possibility of our eternal envattment is due to Crispin Wright (1994). It avoids most of the misunderstandings that have been elicited by Putnam's original presentation of the argument in "Reason, Truth and History" (1981). But it is still open to the charge of question-begging. True enough, the premisses of the argument (disquotation and externalism) can be (...) formulated and defended without presupposing external objects whose existence appears doubtful in the light of the very skeptical scenario which Putnam wants to repudiate. However, the argument is only valid if we add an extra premiss as to the existence of some external objects. In order to avoid circularity, we should run the argument with external objects which must exist even if we are brains in a vat, e.g. with computers rather than with trees. As long as the skeptic is engaged in a discussion of the brain-in-a-vat scenario, she should neither deny the existence of computers nor the existence of causal relations; for if she does, she is in fact denying that we are brains in a vat. (shrink)

The Neo-Moorean Deduction (I have a hand, so I am not a brain-in-a-vat) and the Zebra Deduction (the creature is a zebra, so isn’t a cleverly disguised mule) are notorious. Crispin Wright, Martin Davies, Fred Dretske, and Brian McLaughlin, among others, argue that these deductions are instances of transmission failure. That is, they argue that these deductions cannot transmit justification to their conclusions. I contend, however, that the notoriety of these deductions is undeserved. My strategy is to clarify, attack, (...) defend, and apply. I clarify what transmission and transmission failure really are, thereby exposing two questionable but quotidian assumptions. I attack existing views of transmission failure, especially those of Crispin Wright. I defend a permissive view of transmission failure, one which holds that deductions of a certain kind fail to transmit only because of premise circularity. Finally, I apply this account to the Neo-Moorean and Zebra Deductions and show that, given my permissive view, these deductions transmit in an intuitively acceptable way—at least if either a certain type of circularity is benign or a certain view of perceptual justification is false. (shrink)

It is a very curious thing that proponents of Idealism have considered it to be a satisfactory counter to ‘scepticism’, ‘nihilism’, and the like. On the contrary, it seems to me that Idealism is a very close cousin to ‘brain-in-a-vat’ scepticism and other anti-naturalistic fantasies. Moreover, it seems to me that Idealism is inferior to Naturalism for much the same kinds of reasons that ‘brain-in-a-vat’ scepticism and other anti-naturalistic fantasies are inferior to Naturalism: a proper weighing of theoretical (...) virtues discloses that Naturalism is the most virtuous worldview. (shrink)

Safety principles in epistemology are often hailed as providing us with an explanation of why we fail to have knowledge in Gettier cases and lottery examples, while at the same time allowing for the fact that we know the negations of sceptical hypotheses. In a recent paper, Sinhababu and Williams have produced an example—the Backward Clock—that is meant to spell trouble for safety accounts of knowledge. I argue that the Backward Clock case is, in fact, unproblematic for the more sophisticated (...) formulations of safety in the literature. However, I then proceed to construct two novel examples that turn out problematic for those formulations—one that provides us with a lottery-style case of safe ignorance and one that is a straightforward case of unsafe knowledge. If these examples succeed, then safety as it is usually conceived in the current debate cannot account for ignorance in all Gettier and lottery-style cases, and neither is it a necessary condition for knowledge. I conclude from these troublesome examples that modal epistemologists ought to embrace a much more simple and non-reductive version of safety, according to which the notion of similarity between possible worlds that determines in which worlds the subject must believe truly is an epistemic notion that cannot be defined or reduced to notions independent of knowledge. The resulting view is shown to also lead to desirable results with respect to lottery cases, certain quantum phenomena, and a puzzling case involving a cautious brain-in-a-vat. (shrink)

Many philosophers claim that interesting forms of epistemic evaluation are insensitive to truth in a very specific way. Suppose that two possible agents believe the same proposition based on the same evidence. Either both are justified or neither is; either both have good evidence for holding the belief or neither does. This does not change if, on this particular occasion, it turns out that only one of the two agents has a true belief. Epitomizing this line of thought are thought (...) experiments about radically deceived “brains in vats.” It is widely and uncritically assumed that such a brain is equally justified as its normally embodied human “twin.” This “parity” intuition is the heart of truth-insensitive theories of core epistemological properties such as justification and rationality. Rejecting the parity intuition is considered radical and revisionist. In this paper, I show that exactly the opposite is true. The parity intuition is idiosyncratic and widely rejected. A brain in a vat is not justified and has worse evidence than its normally embodied counterpart. On nearly every ordinary way of evaluating beliefs, a false belief is significantly inferior to a true belief. Of all the evaluations studied here, only blamelessness is truth-insensitive. (shrink)

I can be wrong about things I seem to perceive; the conditions might lead me to be mistaken about them. Since I can't rule out the possibility that the conditions are misleading, I can't be sure that I am perceiving this thing in my hand correctly. But suppose that I am able to examine it actively—handling it, looking closer, shining a light on it, and so on. Then, my level of uncertainty goes down; in the limit it is eliminated entirely. (...) Of course, I might be mistaken because I am a brain in a vat, or because some other sceptical scenario obtains. But sceptical scenarios apply not just to this thing in my hand, but to everything all at once. Define "empirical certainty" as the absence of the kind of doubt that spreads to all empirical states of affairs. Sensory exploration, or active examination, can in principle lead to empirical certainty. (shrink)

I will argue that cases of massive deception, such as New Evil Demon cases, as well as one-off cases of local deception present challenges to views according to which epistemic reasons, epistemic warrant, epistemic rationality or epistemic norms are factive. In doing so, I will argue is that proponents of a factive turn in epistemology should observe important distinctions between what are often simply referred to as ‘bad cases.’ Recognizing epistemologically significant differences between deception cases raises serious challenges for those (...) who deny a central role for non-factive aspects of epistemology. (shrink)

It is received wisdom that the skeptic has a devastating line of argument in the following. You probably think, he says, that you know that you have hands. But if you knew that you had hands, then you would also know that you were not a brain in a vat, a brain suspended in fluid with electrodes feeding you perfectly coordinated impressions that are generated by a supercomputer, of a world that looks and moves just like this one. (...) You would know you weren’t in this state if you knew you had hands, since having hands implies you are no brain in a vat. You obviously don’t know you’re not a brain in a vat, though—you have no evidence that would distinguish that state from the normal one you think you’re in. Therefore, by modus tollens, you don’t know you have hands. At least, the skeptic has a devastating argument, it is thought, if we grant him closure of knowledge under known implication, which many of us are inclined to do: roughly, if you know p, and you know that p implies q, then you know q. (shrink)

In everyday life, we think of skepticism as the position of a stubborn person who has higher epistemic standards than others. Hence, the skeptic is someone who defends extravagant ideas. Some skeptics may deny that climate change is real, while others claim that the first moon landing did not take place. Contemporary philosophers think of skepticism in a different way. In their view, skepticism is the conclusion of a paradoxical argument about epistemic statuses like knowledge and reasons. A paradoxical argument (...) is a logically valid argument that, starting from seemingly plausible premises, reaches an absurd conclusion. We introduce two skeptical arguments. The regress argument purports to show that we lack reasons to believe any claim whatsoever because the search for those reasons inevitably leads to an infinite regress. The underdetermination argument seeks to prove that we lack reasons to believe that there are chairs, trees, other people, and so on; it supports that conclusion by citing skeptical hypotheses, including the idea that we might be dreaming (Descartes 1641) or the suggestion that we could be brains in a vat connected to a supercomputer that mimics the pattern of neural activity that would be produced if we were perceiving external objects (Putnam 1981). (shrink)

Those of us who take skepticism seriously typically have two relevant beliefs: (a) it’s plausible (even if false) that in order to know that I have hands I have to be able to epistemically neutralize, to some significant degree, some skeptical hypotheses, such as the brain-in-a-vat (BIV) one; and (b) it’s also plausible (even if false) that I can’t so neutralize those hypotheses. There is no reason for us to also think (c) that the BIV hypothesis, for instance, is (...) plausible or probably true. In order to take skepticism seriously it’s sufficient to hold (a) and (b); one need not hold (c). Indeed, philosophers who accept (a) and (b) never endorse (c). Show me a philosopher who suspects that he is a brain in a vat and I’ll show you someone who is deranged! That’s one thing that bothers undergraduates in philosophy. They object: why on earth do some philosophers take the BIV hypothesis to pose any threat at all to our beliefs given that those very same philosophers think that there’s no real chance that the BIV hypothesis is true? Sure, the BIV hypothesis is formally inconsistent with my belief that I have hands, so if the former is true then my belief is false. But so what? Why should that bare inconsistency matter so much? Is this strange attitude amongst philosophers the result of some logic fetish infecting the philosophical community? It is sometimes said that the skeptical hypotheses are not only inconsistent with our beliefs but are explanatory of our experiences, which is supposed to make them more of a threat. But students aren’t fooled: although the skeptical hypotheses may attempt to explain why our experience is as it is, it’s the kind of attempt appropriate for science fiction movies that are all special effects and virtually no plot. No one with any sense of reality will take the evil demon hypothesis to be even tenuously explanatory. (shrink)

According to MODERATISM, perceptual justification requires that one independently takes for granted propositional hinges like <There is an external world>, <I am not a brain in a vat (BIV)>, and so on. This view faces the truth problem: to offer an account of truth for hinges that is not threatened by skepticism. Annalisa Coliva has tried to solve the truth problem by combining the claim that external world propositions have a substantive truth property like correspondence with the claim that (...) hinges have a deflationary truth property. I argue that the resulting view cannot offer a coherent characterization of ‘skeptical switch scenarios’ while providing an effective anti-skeptical strategy. In a more positive vein, I defend an approach that combines a correspondence conception of truth with epistemological disjunctivism. (shrink)

According to the principle of epistemic closure, knowledge is closed under known implication. The principle is intuitive but it is problematic in some cases. Suppose you know you have hands and you know that ‘I have hands’ implies ‘I am not a brain-in-a-vat’. Does it follow that you know you are not a brain-in-a-vat? It seems not; it should not be so easy to refute skepticism. In this and similar cases, we are confronted with a puzzle: epistemic closure (...) is an intuitive principle, but at times, it does not seem that we know by implication. In response to this puzzle, the literature has been mostly polarized between those who are willing to do away with epistemic closure and those who think we cannot live without it. But there is a third way. Here I formulate a restricted version of the principle of epistemic closure. In the standard version, the principle can range over any proposition; in the restricted version, it can only range over those propositions that are within the limits of a given epistemic inquiry and that do not constitute the underlying assumptions of the inquiry. If we adopt the restricted version, I argue, we can preserve the advantages associated with closure, while at the same time avoiding the puzzle I’ve described. My discussion also yields an insight into the nature of knowledge. I argue that knowledge is best understood as a topic-restricted notion, and that such a conception is a natural one given our limited cognitive resources. (shrink)

Failure to recognize the "realistic" motivations for Putnam's commitment to internal realism has led to a widely shared misunderstanding of Putnam's arguments against metaphysical realism. Realist critics of these arguments frequently offer rebuttals that fail to confront his arguments. Simply put, Putnam's arguments --the brains in a vat argument as well as the model-theoretic argument -- are "reductios" that are intended to show that "metaphysical realism itself is not sufficiently realistic". If that claim can be substantiated then Putnam can go (...) on to argue that his own view is, by comparison, more realistic than metaphysical realism. (shrink)

Reliability theories of epistemic justification face three main objections: the generality problem, the demon-world (or brain-in-a-vat) counterexample, and the clairvoyant-powers counterexample. In Perception and Basic Beliefs(Oxford 2009), Jack Lyons defends reliabilism at length against the clairvoyant powers case. He argues that the problem arises due to a laxity about the category of basic beliefs, and the difference between inferential and non-inferential justification. Lyons argues reliabilists must pay more attention to architecture. I argue this isn’t necessarily so. What really matters (...) for understanding and solving the case involves paying closer attention to the origins of our belief forming capacities, both inferential and non-inferential. Reliabilists should make origins matter more. (shrink)

This paper focuses on a combination of the antiskeptical strategies offered by semantic externalism and the inference to the best explanation. I argue that the most difficult problems of the two strategies can be solved, if the strategies are combined: The strategy offered by semantic externalism is successful against standard skeptical brain-in-a-vat arguments. But the strategy is ineffective, if the skeptical argument is referring to the recent-envatment scenario. However, by focusing on the scenario of recent envatment the most difficult (...) problems of the antiskeptical strategy posed by the inference to the best explanation can be solved. The most difficult problems with this strategy are: Why is an explanation of our experience offered by the skeptical hypothesis more complex than our standard explanation? Why is the more complex explanation less likely to be true? By focussing on the recent envatment hypothesis both questions can be answered satisfactorily. Therefore, the combination of semantic externalism and the inference to the best explanation yields a powerful antiskeptical argument. (shrink)

On Fred Dretske’s account of knowledge, the Epistemic Closure Principle for knowledge is not valid. Dretske takes this to be a virtue since the account is thus able to saves ordinary knowledge from skepticism. On it, you may know that you have hands, although you do not know that you are not a handless brain in a vat. As a correlate, the account also has to countenance the existence of what has come to be known as ‘abominable conjunctions’ – (...) conjunctions of the form ‘I know I have hands but I do not know that I am not a handless brain in a vat’. These conjunctions are abominable in that they look false or in some way incoherent. Dretske suggests that the abomination is merely pragmatic and can be explain in terms of conversational features, more precisely, in terms of the Gricean Conversation Principles and its associated Maxims of Conversation. I argue that no such Gricean explanation is forthcoming, and that the abomination cannot be thought of as a merely pragmatic or conversational phenomenon. As I show, the abomination goes deeper, into the semantics. (shrink)

Tim Button explores the relationship between words and world; between semantics and scepticism. -/- A certain kind of philosopher – the external realist – worries that appearances might be radically deceptive. For example, she allows that we might all be brains in vats, stimulated by an infernal machine. But anyone who entertains the possibility of radical deception must also entertain a further worry: that all of our thoughts are totally contentless. That worry is just incoherent. -/- We cannot, then, be (...) external realists, who worry about the possibility of radical deception. Equally, however, we cannot be internal realists, who reject all possibility of deception. We must position ourselves somewhere between internal realism and external realism, but we cannot hope to say exactly where. We must be realists, for what that is worth, and realists within limits. -/- In establishing these claims, The Limits of Realism critically explores and develops several themes from Hilary Putnam’s work: the model-theoretic arguments; the connection between truth and justification; the brain-in-vat argument; semantic externalism; and conceptual relativity. The book establishes the continued significance of these topics for all philosophers interested in mind, logic, language, or the possibility of metaphysics. (shrink)

Mario Villalobos and Pablo Razeto-Barry argue that enactivists should understand living beings not as autopoietic systems, but as autopoietic bodies. In doing so, they surrender the principle of multiple realizability of the spatial location of living beings. By way of counterexample, I argue that more motivation is required before this principle is surrendered.

I have developed transcendental arguments to refute several versions of Nick Bostrom’s simulation hypothesis. I called some of these arguments the SIM-style argument. In this paper, I have four main aims. First, I employ the SIM-style argument to remedy a defect in Hilary Putnam’s Brain-in-vat argument. Second, I show that the most radical skepticism, which Tim Button called the nightmarish Cartesian skepticism, can be refuted by the SIM-style argument or by another transcendental argument I develop here. Third, I compare (...) my approach to radical skepticisms with Donald Davidson’s, as it is often regarded as an exemplar of transcendental arguments. Fourth, I explain how the prominent objections, mainly developed by Barry Stroud, to transcendental arguments can incur two undesirable results: psychologism and Kantian skepticism. (shrink)

This paper defends the legitimacy of semantical responses to certain skeptical challenges, with a particular focus on Putnam’s treatment of a particular version of Brain-in-Vat skepticism. It argues that while Putnam’s argument does not provide a general reply to Brain-in-Vat skepticism, the general approach it exemplifies is actually crucial in replying to other skeptical challenges that are otherwise hard to rebut.

The simulation hypothesis is a view of the nature of reality, suggesting that our world is likely a computer simulation created by an advanced civilization. In contrast, illusionism is a theory about the nature of phenomenal consciousness, arguing that phenomenal consciousness is an illusion and can be fully explained in physical terms. I argue that if our world is a simulated construct, illusionism could be incorrect. Specifically, even if our phenomenal experiences can be explained as illusionism suggests, advanced civilizations could (...) still create subjectively indistinguishable experiences by constructing a psychological system external to our world. Since we cannot determine which scenario we belong to, the illusionist explanation is not universally valid. Furthermore, I argue that even if the simulation hypothesis is impossible, illusionism remains flawed. Consequently, while the simulation hypothesis may function as a mere assumption, it exposes the inherent limitations of both illusionism and physicalism. (shrink)