Dreams and Skepticism

The problem of dream skepticism – i.e., the problem of what can justify one’s belief that they are not dreaming – is one of the most famous problems in philosophy. I propose a way of responding to the problem which is available if one subscribes to the theory that the sensory experiences that we have in dreams consist of images (as opposed to false percepts). The response exploits a particular feature of imagination, viz., that it is not possible to simultaneously (...) have two separate imagistic experiences in the same modality. (shrink)

Based on the distinction drawn by James Conant between Cartesian skepticism and Kantian skepticism, I intend to show that Wittgenstein’s remarks on dreaming should not be understood as a direct attack on the former, as commonly held, but as an indirect attack on it, for Wittgenstein approaches Descartes’ dreaming hypothesis by changing the very problematic at stake. Wittgenstein’s attack on skepticism takes one step back from a question about how to distinguish between dreaming that one is experiencing something and actually (...) experiencing it, for this attack focuses on the linguistic conditions of the possibility of something that the Cartesian problematic takes for granted, that is, the very possibility of saying “I am dreaming.” I also intend to show that Wittgenstein’s remarks on dreaming should be read in light of his claim that skepticism is nonsensical put forward in the Tractatus logico-philosophicus as well in his last writings. More specifically, I intend to show that the words “I am dreaming” are nonsensical in the same sense as the alleged proposition “There are physical objects” and the expression of doubt about the existence of physical objects or the external world. (shrink)

Borges’ The Circular Ruins tells the story of a magician who turns out to be a character in a dream. Leibowitz (2021) argues that this scenario undermines the rational indubitability of Descartes’ Cogito. The magician, he argues, is an unreal appearance and therefore does not exist. I argue that Borges drew a distinction between reality and existence and that he was right to do so. There are various senses of reality and the sense in which a dreamt character is unreal (...) poses no threat to their existence or to the indubitability of the Cogito. The magician is unreal because he is a mind-dependent, illusory and fake. Nonetheless, he can be certain that he thinks, therefore he is. (shrink)

In this paper I aim to elucidate Wittgenstein’s claim that the so-called dream argument is senseless. Unlike other interpreters, who understand the sentence “I am dreaming” as contradictory or self-defeating, I intend to elucidate in what sense one should understand it as senseless or, more precisely, as nonsensical. In this sense, I propose to understand the above-mentioned claim in light of Wittgenstein’s criticism of skepticism from the _Tractatus logico-philosophicus_ to his last writings. I intend to show that the words “I (...) am dreaming” are nonsensical in the same sense as the alleged proposition “There are physical objects” or the expression of doubt about the existence of external objects. (shrink)

Jennifer Windt’s Dreaming is an enormously rich and thorough book, developing illuminating connections between dreaming, the methodology of psychology, and various philosophical subfields. I’ll focus on two epistemological threads that run through the book. The first has to do with the status of certain assumptions about dreams. Windt argues that the assumptions that dreams involve experiences, and that dream reports are reliable — are methodologically necessary default assumptions, akin to Wittgensteinian hinge propositions. I’ll suggest that Windt is quietly pre-supposing some (...) sceptical assumptions, and that recent literature in epistemic externalism may bear in important ways on her arguments. The second thread involves the perennial sceptical worry that dreaming threatens ordinary knowledge. I’ll suggest again that Windt makes tacit sceptical assumptions one may wish to resist. (shrink)

A 1% skeptic is someone who has about a 99% credence in non-skeptical realism and about a 1% credence in the disjunction of all radically skeptical scenarios combined. The first half of this essay defends the epistemic rationality of 1% skepticism, appealing to dream skepticism, simulation skepticism, cosmological skepticism, and wildcard skepticism. The second half of the essay explores the practical behavioral consequences of 1% skepticism, arguing that 1% skepticism need not be behaviorally inert.

Putnam’s semantic argument against the BIV hypothesis and Sosa’s argument against dream skepticism based on the imagination model of dreaming share some important structural features. In both cases the skeptical option is supposed to be excluded because preconditions of its intelligibility are not fulfilled (affirmation and belief in the dream scenario, thought and reference in the BIV scenario). Putnam’s reasoning is usually interpreted differently, as a classic case of deception, but this feature is not essential. I propose to interpret BIV’s (...) utterances as cases of reference failure best captured by truth-value gaps. Both anti-skeptical strategies are then vulnerable to the same type of objections (how do we know what state we are in or how do we know what kind of language do we speak). (shrink)

If we hold that perceiving is sufficient for knowing, we can raise a powerful objection to dreaming skepticism: Skeptics assume the implausible KK-principle, because they hold that if we don’t know whether we are dreaming or perceiving p, we don’t know whether p. The rejection of the KK-principle thus suggests an anti-skeptical strategy: We can sacrifice some of our self-knowledge—our second-order knowledge—and thereby save our knowledge of the external world. I call this strategy the Self-Knowledge Gambit. I argue that the (...) Self-Knowledge Gambit is not satisfactory, because the dreaming skeptic can avail herself of a normative counterpart to the KK-principle: When we lack second-order knowledge, we should suspend our first-order beliefs and thereby give up any first-order knowledge we might have had. The skeptical challenge is essentially a normative challenge, and one can raise it even if one rejects the KK-Principle. (shrink)

I argue that Cartesian skepticism about the external world leads to a vicious regress of skeptical attitudes, the only principled and unproblematic response to which requires refraining from taking the very first skeptical step.

Recently, Ernest Sosa (2007) has proposed two novel solutions to the problem of dream skepticism. In the present paper, I argue that Sosa’s first solution falls prey to what I will refer to as the conditionality problem, i.e., the problem of only establishing a conditional—in this case, if x, then I am awake, x being a placeholder for a condition incompatible with dreaming—in a context where it also needs to be established that we can know that the antecedent holds, and (...) as such can infer the consequent, i.e., I am awake. Sosa’s second solution, in terms of so-called reflective knowledge, is shown to land him in the dilemma of either facing yet another conditionality problem, or violating an internalist constraint that he explicitly grants the skeptic with respect to what kind of factors can be legitimately invoked in our account of how we may know the relevant antecedent. For these reasons, I conclude that Sosa has not solved the problem of dream skepticism. (shrink)

'What is real?' has been one of the key questions of philosophy since its beginning in antiquity. But it is not just a question that philosophers ask. This Very Short Introduction discusses what reality is by looking at a variety of arguments, theories, and thought-experiments from philosophy, physics, and cognitive science.

After resolving the dreaming doubt at the end of the Sixth Meditation, Descartes concedes to Hobbes that one could apply the criterion for waking experience in a dream and thus be deceived, but he no longer considers this possibility to have skeptical force. I argue that this is a legitimate response by Descartes since 1) the dreaming doubt in the Sixth Meditation is no longer a global skeptical hypothesis as it is in the First, and 2) the level of certainty (...) that sensory experience must meet in the Sixth Meditation is lower than it must meet in the First. (shrink)

Ernest Sosa has proposed two different ways to respond to dreaming skepticism. In this paper I argue that Sosa's first response —which centers on holding that we have no beliefs in dreams— does not appear to be successful against either the hyperbolic or the realistic dreaming skeptic. I also argue that his second attempt to respond to the dreaming skeptic by arguing that perceptual knowledge indeed counts as what he calls "animal knowledge", may succeed but requires us to perform what (...) appears to be some radical surgery on the concept of knowledge; a radical surgery that, as I show, is probably unnecessary to avoid dreaming skepticism. Finally, I sketch some independent considerations why I think that the hyperbolic skeptic's dreaming argument is not acceptable. Ernesto Sosa propone dos maneras de responder al escéptico del sueño. En este ensayo argumento que su primera propuesta, según la cual no tenemos creencias en los sueños, no parece ser una buena respuesta en contra de ninguno de los escepticismos del sueño, de los cuales distingo dos tipos: el hiperbólico y el realista. También argumento que su segunda propuesta para responder al escéptico del sueño, en la que argumenta que el conocimiento perceptual sí cuenta como conocimiento animal, quizá resulte exitosa; sin embargo, ésta requiere llevar a cabo una cirugía radical en el concepto de conocimiento; una cirugía que, como muestro, es probablemente innecesaria para evitar el escepticismo del sueño. Finalmente bosquejo algunas razones independientes por las cuales considero que el argumento del escéptico hiperbólico del sueño no es aceptable. (shrink)

In my remarks, I discuss Sosa's attempt to deal with the sceptical threat posed by dreaming. Sosa explores two replies to the problem of dreaming scepticism. First, he argues that, on the imagination model of dreaming, dreaming does not threaten the safety of our beliefs. Second, he argues that knowledge does not require safety, but a weaker condition which is not threatened by dreaming skepticism. I raise questions about both elements of his reply.

In my remarks, I discuss Sosa's attempt to deal with the sceptical threat posed by dreaming. Sosa explores two replies to the problem of dreaming scepticism. First, he argues that, on the imagination model of dreaming, dreaming does not threaten the safety of our beliefs. Second, he argues that knowledge does not require safety, but a weaker condition which is not threatened by dreaming skepticism. I raise questions about both elements of his reply.

Abstract: Ernest Sosa has recently articulated an insightful response to skepticism and, in particular, to the dream argument. The response relies on two independent moves. First, Sosa offers the imagination model of dreaming according to which no assertions are ever made in dreams and no beliefs are involved there. As a result, it is possible to distinguish dreaming from being awake, and the dream argument is blocked. Second, Sosa develops a virtue epistemology according to which in appropriately normal conditions our (...) perceptual beliefs will be apt. Hence, in these conditions, we will have at least animal knowledge, and the conclusion of the dream argument is undermined. In this article, I examine various moves that the skeptic can make to resist Sosa's challenge, and I contrast the proposal to a neo-Pyrrhonian stance. In the end, there is surprisingly little disagreement about the status of ordinary perceptual beliefs in the two stances. (shrink)

Various possibilities, that one is dreaming, that one is being deceived by a deceitful demon, that one is a brain in the vat being stimulated to think one has a body and is in a regular world, have been invoked to show that all one's experience-based beliefs might be false. Descartes in Meditation I advises that in order not to lapse into his careless everyday view of things he, or at least his meditator, should pretend that all his experience-based beliefs, (...) indeed all his …. (shrink)

The skeptical Dream argument appeals to the possibility of dreaming. The skeptic holds that states of being awake are subjectively indistinguishable from possible dream states and that this means that we do not know that we are awake. This, the skeptic then claims, means that we have to accept that we do not have external world knowledge.It is natural to assume that there must be a connection between the Dream argument and epistemic internalism, the view that a belief is justified (...) for a given person if and only if the person has cognitive access to all the factors that are needed for the belief to be justified. The problem, the skeptic thinks, is that in order for my belief that I am awake to be justified I have to have cognitive access to something that establishes that I am awake. But according to the skeptic, even if I am awake, this is not something I have cognitive access to. However, the more precise connections between internalism and the skeptical argument are not so clear. (shrink)

Having fascinated some of the greatest philosophers from the earliest times, dreaming figures importantly in the history of philosophy, as in Plato’s Theaetetus, Augustine’s Confessions, and, perhaps most famously, Descartes’s Mediations. By far the greatest philosophical focus on dreaming has been epistemic: Socrates suggests to Theaetetus that since he cannot tell whether he is dreaming, he cannot trust his senses to know contingent facts about the world around him. And a similar worry drives Descartes’s radical doubt in the First Meditation. (...) We might think that dream skepticism is, among the radical Cartesian skeptical scenarios, a particularly worrying one, since dreams, unlike evil demons, are a commonplace of everyday life. (shrink)

The paper deals with Wittgenstein’s treatment of radical skepticism. He holds from his earliest work to his last that skepticism is senseless and therefore no rebuttal, such as G.E. Moore offered, is necessary.

There are two epistemological problems connected with dreaming, which are of different kinds and require different treatment. The internal problem is best seen as a problem of rational consistency, of how we can maintain all of: Dreams are experiences we have during sleep. Dream-experiences are sufficiently similar to waking experiences for the subject to be able to mistake them for waking experiences. We can tell that we are awake. (1)-(3) threaten to violate a requirement on discrimination: that we can only (...) tell Xs from Ys if there is some detectable difference between Xs and Ys. Attempts to solve the problem by Descartes and Williams are considered. It is suggested that if we take account of levels of epistemic risk, we can use Descartes's criterion of lack of coherence, at least with hindsight - which is the time when we need to use it. (shrink)

Ernest Sosa has argued that the solution to dream scepticism lies in an understanding of dreams as imaginative experiences – when we dream, on this suggestion, we do not believe the contents of our dreams, but rather imagine them. Sosa rebuts scepticism thus: dreams don’t cause false beliefs, so my beliefs cannot be false, having been caused by dreams. I argue that, even assuming that Sosa is correct about the nature of dreaming, belief in wakefulness on these grounds is epistemically (...) irresponsible. The proper upshot of the imagination model, I suggest, is to recharacterize the way we think about dream scepticism: the sceptical threat is not, after all, that we have false beliefs. So even though dreams don’t involve false beliefs, they still pose a sceptical threat, which I elaborate. (shrink)

Broadly speaking, there are two different ways in which one might defend skepticism – an a priori wayand an empirical way. My first task in this paper is to defend the view that the preferred way to defendskepticism is empirical. My second task is to explain why this approach actually makes sense. Iaccomplish this latter task by responding to various criticisms one might advance against the possibilityof empirically defending skepticism. In service of this response, I distinguish between two differentkinds of (...) hallucination, ‘metaphysical’ and ‘ordinary’, and seek to clarify the notion of a‘presupposition’. (shrink)

As sources of knowledge, perception and testimony are both vulnerable to sceptical arguments. To both arguments a Moorean response is possible: both can be refuted by reference to particular things known by perception and testimony. However, lies and dreams are different possibilities and they are different in a way that undercuts the plausibility of a Moorean response to a scepticism of testimony. The condition placed on testimonial knowledge cannot be trivially satisfied in the way the Moorean would suggest. This has (...) substantial implications for any non-sceptical epistemological theory of testimony. (shrink)

The reason Descartes cites for invoking the demon argument in addition to the dream argument is that the demon argument is intended to broaden the scope of Descartes’ scepticism, to subsume additional beliefs under it. I present an additional, unfamiliar reason. There is, I argue, an important difference between the two sceptical arguments. It pertains not to their scope, but to their “depth”, to the kind of scepticism they are capable of inducing.

“The Matrix is a computer-generated dreamworld built to keep us under control” Morpheus, early in The Matrix. “ In dreaming, you are not only out of control, you don’t even know it…I was completely duped again and again the minute my pons, my amygdala, my perihippocampal cortex, my anterior cingulate, my visual association and parietal opercular cortices were revved up and my dorsolateral prefrontal cortex was muffled” ” J. Allan Hobson, The Dream Drugstore, p.64 The Matrix is an exercise in (...) ambivalence, and at the very heart of that ambivalence lies the Dream. In our dreams, we are not in control. Real dreaming, unlike many popular philosophers’ fictions, is an altered state, closely related to the states induced by chemical manipulations such as the use of (certain) medical or recreational drugs. The dreaming brain is not like the wakeful brain. Normal sensory input is blocked, attentional capacities are impaired or lost, memory is distorted, reasoning and logic are weakened, narratives run wild, self-reflection is dampened or destroyed, emotion and instinct are hyperstimulated, and forms of ‘top-down’ willed control and decision-making diluted and easily overwhelmed. (shrink)

Descartes' Meditations do not end up sceptical at all. In fact, the sixth meditation displays an intriguing epistemological optimism. Descartes affirms without reservation that knowledge of the external world is possible. The antisceptical argument at the end of the Meditations is often interpreted as a refutation of dream scepticism, with the conclusion that a person in the waking state can also determine that he or she is awake. We examine the logic of the argument in detail and find that this (...) is not the point. Our reconstruction shows that the question of waking or dreaming which seems to be so crucial for Descartes can even be dropped from his argument. (shrink)

That conception is orthodox in today’s common sense and also historically. Presupposed by Plato, Augustine, and Descartes, it underlies familiar skeptical paradoxes. Similar orthodoxy is also found in our developing science of sleep and dreaming.[2] Despite such confluence.

Michael Williams believes that scepticism about the externalworld seems compelling only because the considerations that underpin it are thoughtto be ``mere platitudes'' about e.g., the nature and source of human knowledge, and hence,that if it shown through a ``theoretical diagnosis'' that it does not rest upon suchplatitudes, but contentious theoretical considerations that we are no means bound toaccept, we can simply dismiss the absurd sceptical conclusion. Williams argues thatscepticism does presuppose two extremely contentious doctrines, however, he admits thatif these doctrines (...) are themselves motivated by ``platitudes'' then scepticism follows. Iaddress Williams's arguments for thinking scepticism must presuppose these doctrines,and argue that he overlooks a way that they can be seen as motivated by mere platitudes.Thus, I conclude that William's novel rejection of scepticism fails. (shrink)

Skeptical dream-arguments are intended as general challenges to our epistemic claims concerning the world. They argue that we can never rule out the possibility of merely dreaming what we believe to perceive. In my paper I will scrutinize whether any kind of such argument is sound. On my view, many versions of this argument are defective. They are either too weak to challenge all kinds of our epistemic claims or they rely on implausibly strong epistemic principles. More plausible versions of (...) the argument can be rebutted by the results of recent empirical dream research. As I will argue, there is an introspective criterion for currently being awake. Nevertheless there is one version of the dream-argument, which I will call quasi-dream-argument, that survives all criticism and brings out the structure of a compelling skeptical argument very clearly. (shrink)

Of course, if infallibilism about such knowledge is true, then it is true that one can never know that one is not dreaming. But, of course, if infallibilism is true, then there is also no special difficulty posed for one’s having knowledge in general by one’s not knowing in particular that one is not dreaming: one would know either nothing or next to nothing anyway, regardless of one’s not knowing in particular that one is not dreaming. Yet epistemologists have generally (...) regarded the challenge of knowing that one is not dreaming as being at least somewhat pivotal or special. This suggests that, although they wish not to concede that no one can know that one is not dreaming, they wish to be fallibilists about knowledge. (shrink)

Richard Fumerton’s “Principle of Inferential Justification” holds that, in order to be justified in believing P on the basis of E, one must be justified in believing that E makes P probable. I argue that the plausibility of this principle rests upon two kinds of mistakes: first, a level confusion; and second, a fallacy of misconditionalisation. Furthermore, Fumerton’s principle leads to skepticism about inferential justification, for which reason it should be rejected. Instead, the examples Fumerton uses to motivate his principle (...) can be accounted for using a different principle: in order for S to be justified in believing P on the basis of E, it must be true that E makes P probable. The latter principle can be independently motivated and does not lead to skepticism. (shrink)

In a recent, and influential, article, Crispin Wright maintains that a familiar form of scepticismwhich finds its core expression in Descartes’ dreaming argumentcan be defused (or, to use Wright’s own parlance, “imploded”), by showing how it employs self-defeating reasoning. I offer two fundamental reasons for rejecting Wright’s ‘implosion’ of scepticism. On the one hand, I argue that, even by Wright’s own lights, it is unclear whether there is a sceptical argument to implode in the first place. On the other, I (...) claim that even on the supposition that Wright has indeed succeeded in setting-up such an argument, he nevertheless fails to follow-through with an adequate response. A diagnosis of the failure of Wright’s approach is then given in the context of the wider sceptical debate. (shrink)

Is there a way to tell whether what you remember was something you dreamt or something that really happened without making reference to coherence criteria? I suggest contra Descartes that there is a certain sign ‘by means of which one can distinguish clearly between being awake and being asleep’. This certain sign is the intensive magnitude associated with every sensation.

This dissertation examines a traditional philosophical problem within a novel framework. The so-called "problem of the external world" is a problem about how knowledge, and even reasonable belief, about the world are possible, and it is best characterized as the challenge to show how and why scepticism about the external world---the absurd view that such knowledge is impossible---is incorrect. My framework for the examination of this problem involves two major elements. ;The first element involves a general characterization of the nature (...) of "perennial" philosophical problems, like the problem of the external world, that attempts to isolate the specific features that render them problematic, which, in turn, isolates what is required for their solutions. Applying this characterization to the problem of the external world, the second element of the framework involves distinguishing between two approaches for the solving of the problem, which I label "constructive" and "deflationary," and establishing why the latter approach is preferable. I further distinguish between two general types of deflationary approaches---"therapeutic diagnosis," and "theoretical diagnosis"---and examine in detail what I take to be the major representatives of each strategy. In the process I offer novel critical interpretations of the work of G. E. Moore and Ludwig Wittgenstein, as well as some of the first detailed critical discussions of recent responses to scepticism by Hilary Putnam and Michael Williams. ;My general aim is to assess the strengths and weaknesses of both deflationary approaches as responses to scepticism. I argue that all of these attempts to solve the problem are unsatisfactory, and that the challenge to show why scepticism about the external world is incorrect has not yet been met. However, and this is perhaps the most important contribution of the dissertation, I hope to have shown where we should and should not look to meet the challenge. (shrink)

According to one fairly standard reconstruction Descartes' Dream Argument has two crucial premises. The paper starts by analysing two important failed attempts, discussed by Barry Stroud and Mark Steiner, at justifying one of these premises. On this basis then an alternative is suggested to the line of interpretation assumed by these attempts which easily resolves the problems they face. It is shown that this alternative and its rivals are on a par with respect to the other crucial premise of the (...) Dream Argument and that it is superior to the others in avoiding scepticism or infinite regress. (shrink)

lecture 1. Introduction : intellectual history and conceptual change -- lecture 2. The dawn of the 17th century : Aristotelian scholasticism -- lecture 3. The new vision of Francis Bacon -- lecture 4. The new astronomy and cosmology -- lecture 5. Descartes's dream of perfect knowledge -- lecture 6. The specter of Thomas Hobbes -- lecture 7. Skepticism and Jansenism : Blaise Pascal -- lecture 8. Newton's discovery -- lecture 9. The Newtonian revolution -- lecture 10. John Locke, the revolution (...) in knowledge -- lecture 11. The Lockean moment -- lecture 12. Skepticism and Calvanism : Pierre Bayle -- lecture 13. The moderns, the generation of 1680-1715 -- lecture 14. Introduction to deism -- lecture 15. The conflict between deism and Christianity -- lecture 16. Montesquieu and the problem of relativism -- lecture 17. Voltaire, bringing England to France -- lecture 18. Bishop Joseph Butler and God's providence -- lecture 19. The skeptical challenge to optimism, David Hume -- lecture 20. The assault upon philosophical optimism, Voltaire -- lecture 21. The philosophes : the triumph of the French Enlightenment -- lecture 22. Beccaria and enlightened reform -- lecture 23. Rousseau's dissent -- lecture 24. Materialism and naturalism, the boundaries of the Enlightenment. (shrink)

Dans la première méditation, Descartes a conclu, en regard des songes, « qu'il n'y a point d'indices concluants, ni de marques assez certaines par où l'on puisse distinguer nettement la veille d'avec la sommeil [...] » . À la fin de la sixième méditation, il a conclu qu'il y a de tels indices, mais qu'on a besoin de la garantie de Dieu pour savoir si ces indices sont réellement des indices de la veille. Cottingham a proposé une objection générale contre (...) tels indices de la veille: On peut rêver cet indice. Selon les raisonnements de Cottingham, il s'agit de l'existence de l'indice. Or, chez Leibniz et Descartes il ne s'agit pas de cela, mais il est question de savoir si l'indice est vraiment un indice de la veille. La prétention que l'indice puisse être présent en songe fait une pétition de principe. Notre examen des indices que Leibniz et Berkeley ont proposés révèle cette pétition. (shrink)

Suppose that someone writes an argument on a blackboard which leads to the conclusion that he may, at that time, be dreaming. He goes over it, considers its validity, the truth of its premises, its assumptions and so on, and then to his dismay, he judges that he is compelled to conclude that he may be dreaming. He goes over the argument repeatedly and carefully, but finds the conclusion ‘inescapable’. If reviewing the argument on the blackboard may be taken as (...) an analogue of reviewing thoughts before one's mind, then his condition seems like the condition which Descartes describes at the beginning of the Second Meditation: ‘The meditation of yesterday filled my mind with so many doubts that it is no longer in my power to forget them. And yet I do not see in what manner I can resolve them; and just as if I had all of a sudden fallen into very deep water, I am so disconcerted that I can neither make certain of setting my feet on the bottom, nor can I swim and support myself on the surface.’. (shrink)