Varieties of Skepticism

The present research aims to examine the different accounts of induction given by Aristotle, Leibniz, Hume, Carnap and De Finetti, trying to support that probability calculus offers a sufficient grounding of inductive logic. The term induction had been contrasted to deduction, by Aristotle. The Neoplatonic philosopher Alcinous suggested that dialectic firstly investigates the substances and then the accidents. There are five kinds of dialectic reasoning: division, definition, analysis, induction and syllogistic. The first three concern with substances, the last two with (...) accidents. Although Leibniz regarded probability theory as a basis of inductive logic, Hume’s skepticism was seminal for the reappraisal of the role of induction in modern philosophy. Enhancing Hume’s criticism, Popper and Wittgenstein completely denied that scientists use induction. Hans Reichenbach, however, attempted to build a theory of justification for the use of induction, based on a factual basis of other successful predictive methods that make induction feasible (Earman & Salmon 1999). Moreover, Buchdall (1969) stressed that we must distinguish the inductive process of the scientist from the inductive conclusion, which comes after the completion of observation and experimentation. (shrink)

In everyday life, people think of skepticism as the position of a stubborn person who rejects what other people believe in. 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. There are two major skeptical arguments. The regress argument purports to show that people 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 people lack reasons to believe that there are things such as chairs, trees, other people, and so on. It supports that conclusion by citing skeptical hypotheses, including the idea that people might be dreaming or the suggestion that people could be brains in a vat connected to a supercomputer that mimics the pattern of neural activity that would be produced if they were perceiving external objects. (shrink)

This paper distinguishes two varieties of skepticism and the varieties of philosophical response those skepticisms have engendered. The aim of the exercise is to furnish a perspicuous overview of some of the dialectical relations that obtain across some of the range of problems that philosophers have called (and continue to call) “skeptical”. I argue that such an overview affords a number of forms of philosophical insight.

The legacy of the Platonic dialogues may well lie, not in any classical idealist “doctrine of forms,” but in an inquisitive stance towards the puzzle behind any such doctrine—how thought can be about anything at all. This Platonic puzzle may, however, yield a different guise of idealism that is recognizably diagnostic: it aims to dispel our worry about thought’s objectivity as a confusion, engendered by a self-alienation of thought. These themes of diagnosis and idealism resurface in Wittgenstein, who in his (...) treatment of rules calls for an understanding of thought’s normativity from within. This is taken up by Cora Diamond, who urges philosophy to attend to thought’s real needs by exorcizing any desire for agreement with something other than itself. I argue that Wittgenstein and Diamond lead us back to Kant’s idealism, which identifies transcendental realism as the deep-seated prejudice at the root of the puzzle. (shrink)

Traditionally, philosophers have been skeptical that the imagination can justify beliefs about the actual world. After all, how could merely imagining something give you any reason to believe that it is true? However, within the past decade or so, a lively debate has emerged over whether the imagination can justify empirical belief and, if so, how. This paper provides a critical overview of the recent literature on the epistemology of imagination and points to avenues for future research.

What should we do when faced with powerful theoretical arguments that support a severe change in our personal beliefs and commitments? For example, what should new parents do when confronted by unanswered anti-natalist arguments, or two lovers vexed by social theory that apparently undermines love? On the one hand, it would be irrational to ignore theory just because it’s theory; good theory is evidence, after all. On the other hand, factoring in theory can be objectifying, or risks unraveling one's life, (...) fracturing one's identity or social relations. Sometimes, then, following the evidence where it apparently leads would mean not merely changing what we think but who we are. Some might say that there’s something right about the thought that theory can bear on what we ought to believe, it’s just that when we work with full beliefs, only then do we seriously risk having to substantially alter our doxastic economy when pressed by exceptional theoretical arguments. When we work with partial beliefs, however, this risk is greatly diminished. Others will say that we can advocate or champion revisionary positions whilst rationally retaining our pre-theoretical personal convictions. Still others will argue that we should adopt a Moorean posture towards the revisionary arguments. I argue that each response is inadequate, and argue instead that we are permitted to bracket certain kinds of theoretical evidence against our beliefs because of the personal and ethical risks born out of giving them serious consideration. In turn, some of philosophy's doxastic influence is constrained by its attendant ethical risks: the personal enjoys a partial insulation from the theoretical. I close by addressing what this means for practicing philosophers. (shrink)

Remarks in Wittgenstein’s On Certainty present a view according to which all knowledge rests on commitments to things we do not know. In his usual manner, Wittgenstein does not present a clearly defined set of premises designed to support this view. Instead, the reasons emerge along with the view through a series of often cryptic remarks. But this does not prevent us from critically assessing the position (or positions) one finds in the work. This paper attempts to do that in (...) the form of a philosophical dialogue. The challenges to Wittgenstein’s view raised here center on: the extent to which hinge commitments can plausibly be regarded as rules of a language-game rather than rationally assessable propositions, mutual support versus bottom up notions of justification, the subject and context relativity of hinge commitments, the difference between justification and persuasion, whether propositions of the form p is hinge are themselves hinge, and the general viability of Wittgenstein’s view as an alternative to epistemological skepticism and Moorean anti-skepticism. (shrink)

This is a draft translation of the first letter of G.E. Schulze's Aenesidemus. Comments and corrections welcome.

Free will sceptics claim that we lack free will, i.e. the command or control of our conduct that is required for moral responsibility. There are different conceptions of free will: it is sometimes understood as having the ability to choose between real options or alternatives; and sometimes as being the original or true source of our own conduct. Whether conceived in the first or in the second way, free will is subject to strong sceptical arguments. However, free will sceptics face (...) a difficulty: doubting the existence of free will might itself be problematic, whether free will exists or not. Three main considerations are offered in support of this claim. Firstly, it is said that free will sceptics confuse contexts: even if they are right to doubt the existence of free will in the philosophy classroom, they are wrong to do so in other contexts, such as day-to-day interactions or a court of law. Secondly, it is said that free will scepticism is incompatible with inescapable and indispensable human practices such as practical deliberation or moral criticism and evaluation. For, to deliberate about what to do, we must presume that we have true options or alternatives. And to judge that some human practices are wrong, we need to assume the existence of moral responsibility. Thirdly, free will scepticism is sometimes said to be self-defeating, on the grounds that it cannot be rational to believe free will scepticism, because free will is required for rationality. This thesis critically assesses these arguments. None takes free will scepticism down, but all are instructive about how not to be a sceptic. They trace the ‘contours’ of free will scepticism by discrediting some conceptions of free will and some arguments for free will scepticism. (shrink)

Kirja-arvio: Malin Grahn-Wilder : Skeptisismi: Epäilyn ja etsimisen filosofia. Gaudeamus, Helsinki 2016. 453 sivua. Mitä on tieto ja kellä sitä on? Voimmeko tietää miten asiat todella ovat? Voimmeko ylipäätään tietää mitään? Malin Grahn-Wilderin toimittama teos Skeptisismi on kattava läpileikkaus skeptisismin historiasta antiikin juuriltaan aina nykyajan keskusteluihin saakka. Samalla se sisältää ensimmäistä kertaa suomeksi käännettynä useammankin filosofian historialle ehdottoman olennaisen kirjoituksen.

Sensitivity account of knowledge states that if one knows that _p_ (via method M), then were _p_ false, one would not believe that _p_ via M. This account has been highly controversial. However, even its critics tend to agree that the account enjoys an important advantage of solving the Gettier problem—that is, it explains why Gettierized beliefs are not knowledge. In this paper, I argue that this purported advantage of sensitivity is merely illusory. The account cannot, in principle, solve the (...) Gettier problem. Moreover, another formulation of sensitivity—which is fully in line with Nozick’s original account—is not unscathed either. (shrink)

Philosophical skepticism about the external world seeks to call into question our knowledge of the external world. Some kinds of philosophical skepticism employ skeptical hypotheses to prove that we cannot know anything about the external world. Putnam tried to refute this kind of skepticism by adopting semantic externalism; but, as is now generally accepted, Putnam’s argument is epistemically circular. Brueckner proposes some new, “simple” arguments that in his view are not circular. In this paper we evaluate Brueckner’s simple arguments for (...) refuting skepticism about the external world, and seek to demonstrate that they fail to prove that we can have knowledge about the external world. However, by appeal to the principle of privileged access, one of the Brueckner’s arguments does indeed succeed in showing that we can have justified beliefs about the external world. (shrink)

Outside the philosophy classroom, global skeptics – skeptics about all (purported) knowledge of the external world – are rare. But there are people who describe themselves as “skeptics” about various more specific domains, including self-professed “skeptics” about the reality of anthropogenic climate change. There is little to no philosophical literature that juxtaposes the climate change skeptic with the external world skeptic. While many “traditional” epistemologists assume that the external world skeptic poses a serious philosophical challenge in a way that the (...) climate change skeptic doesn’t, many “applied” or “social” epistemologists assume that there isn’t much to be learned from debates about the external world skeptic, finding her challenge to be distant from both common sense and real-world concerns. I try to show that both of these views are mistaken. The external world skeptic raises deep questions that are important for our everyday deliberation about what to believe, and there are significant structural parallels between the arguments for external world skepticism and those for at least a form of climate change skepticism that is idealized – but not too idealized! – from the views of flesh-and-blood climate change skeptics. As such, we have strong reasons to think in parallel about how to reply to both skeptics’ challenges. I thus finish by (briefly) considering how different widespread responses to the external world skeptic might or might not generalize happily to the climate change skeptic’s challenge. (shrink)

What do Philosophers do? Skepticism and the Practice of Philosophy. By Maddy Penelope.

Hawthorne discusses (without endorsing) the following instance of our (T1) , “One knows that one is seeing a desk by taking for granted, but without knowing, that one is not a brain in a vat” (510). We believe that this is a commonsensical way of describing an ordinary situation. Intuitively, one knows one is seeing a desk. Intuitively one is normally justified in taking it for granted that one is not a brain in a vat, but one does not know (...) one isn’t a brain in a vat. (shrink)

Cartesian skepticism requires scenarios of massive deception to make its case. The inability to rule out such possibilities in which our beliefs about the external world are massively mistaken motivates the conclusion that we lack everyday knowledge. Some authors have emphasized that such scenarios are implausible. Others have instead claimed that scenarios are irrelevant to skepticism. If skepticism can make its case, they argue that scenarios of massive deception are not the way to do it. This thesis possesses a distinct (...) anti-sceptical weight. Deprived of its scenario, epistemological skepticism must find a different reason for it to be taken seriously, which might be a tall order. This paper defends the idea that scenarios do not constitute the essential element of the skeptical threat. However, it takes this result in the opposite direction. We aim to show that skepticism without scenarios constitutes a bigger and more legitimate philosophical problem than otherwise. Additionally, it also offers the possibility of achieving a unified understanding of skepticism that is so far lacking in contemporary epistemology, allowing us to better understand what can constitute a satisfactory anti-skeptical strategy. (shrink)

This paper challenges Sosa’s account of the epistemic propriety of suspension of judgment. We take the reader on a test drive through some common problem cases in epistemology, to see how the account of suspension deals with them. Section 1 outlines Sosa’s account of accurate and apt suspension. Sections 2 and 3 focus on the skeptical scenario to argue that Sosa makes it too easy for suspension to be accurate and apt. Section 4 applies Sosa’s account of accurate and apt (...) suspension to BonJour’s case of Norman the clairvoyant. The upshot is that Sosa makes accurate and apt suspension not only too easy but also too hard. (shrink)

This article gives a Bayesian argument showing that, even if your total empirical evidence confirms that you have zillions of duplicate Boltzmann Brains, that evidence does not confirm that you are a Boltzmann Brain. The article also attempts to explain what goes wrong with several of the sources of the temptation for thinking that such evidence does have skeptical implications.

According to the simulation hypothesis, the world we live in is a computer simulation. According to longtermism, we should aim to bring about the best possible future. In this paper, I argue that there is a tension between the two: insofar as we have reason to think we are living in a computer simulation, we have reason to think the longtermist project will fail (or has already failed). I make my case by developing a novel version of the problem of (...) evil. It says that there exist certain forms of evil in our world that longtermist philosophers have argued we should try to eradicate. But then, the existence of those evils give us reason to think our world is not a computer simulation run by a being aligned with longtermist values. In short, the more that longtermists think we could make the world a better place in the future, the more troubling they should find it that the world is not already a better place, given the assumption that we are living in a computer simulation. (shrink)

One interesting and potentially attractive feature of the sensitivity account of knowledge is that it not only preserves knowledge of ordinary propositions, but also concedes the skeptic's intuition that we do not know skeptical hypotheses do not obtain. This paper challenges the sensitivity‐based reply to the skeptic, advocated by Robert Nozick, among others. Sensitivity generates an implausibly bizarre result that although we do not know we are not brains in vats (because a belief to this effect is insensitive), a real (...) BIV who is in a much worse epistemic situation can sensitively believe that it is not in the good case. This result reveals a fundamental problem with the sensitivity conditional: its antecedent is not suitable for picking out possibilities that are relevant for our epistemic evaluation. I then offer a systematic explanation of why it is the safety account—the main competitor of sensitivity—that picks out a more suitable set of possibilities. A consequence of this comparison is that the safety account delivers an overall more satisfying reply to the skeptic than sensitivity does. (shrink)

The philosophy of superdeterminism is based on a single scientific fact about the universe, namely that cause and effect in physics are not real. In 2020, accomplished Swedish theoretical physicist, Dr. Johan Hansson published a physics proof using Albert Einstein’s Theory of Special Relativity that our universe is superdeterministic meaning a predetermined static block universe without cause and effect in physics. A prominent theory in cosmology is that our universe originated from a random quantum fluctuation. However, some object that such (...) a large universe creating quantum fluctuation is much less likely to occur than Boltzmann Brains or even a small universe creating quantum fluctuation. But, any quantum event can be predetermined to occur at any time by the Creator of our universe. Consequently, a large universe creating quantum fluctuation occurring at the beginning of time can be predetermined to occur before any appearance of Boltzmann Brains or small universe creating quantum fluctuations. The philosophy of superdeterminism regards our universe from quantum fluctuation to be a predetermined miraculous quantum event by a Creator God. (shrink)

In everyday life, we often understand skepticism as a position that one may set aside because of its absurdity or incoherence. In Greek philosophy, skepticism was rather an inquiring attitude that led to the suspension of judgment and, as a result, the freedom from distress. In Modern philosophy, many philosophers viewed skepticism as a phase of thought that had to be overcome before laying firm foundations for the sciences. These pictures differ from the outlook that dominates current analytic epistemology, where (...) skepticism has normally been understood as a series of paradoxes that arise when we reflect on the workings of ordinary epistemic concepts like KNOWLEDGE and EPISTEMIC JUSTIFICATION. A skeptical paradox emerges when we identify a condition that seems to be necessary to have knowledge or epistemic justification, while it also seems that that condition cannot be met. This chapter explains why the picture of skepticism as a series of paradoxes is central to contemporary analytic epistemology and identifies some of the main features of skeptical paradoxes about the external world. After identifying two types of replies, it presents two influential paradoxes based on the closure and underdetermination principles, identifies some relevant differences between the two paradoxes, and critically examines some attempts at solving them. (shrink)

Many philosophers have been attracted to a restricted version of the principle of indifference in the case of self‐locating belief. Roughly speaking, this principle states that, within any given possible world, one should be indifferent between different hypotheses concerning who one is within that possible world, so long as those hypotheses are compatible with one's evidence. My first goal is to defend a more precise version of this principle. After responding to several existing criticisms of such a principle, I argue (...) that existing formulations of the principle are crucially ambiguous, and I go on to defend a particular disambiguation of the principle. According to the disambiguation I defend, how we should apply this restricted principle of indifference sensitively depends on our background metaphysical beliefs. My second goal is to apply this disambiguated principle to classical skeptical problems in epistemology. In particular, I argue that Eternalism threatens to lead us to external world skepticism, and Modal Realism threatens to lead us to inductive skepticism. (shrink)

Verschwörungstheorien (VTn) sind in der erkenntnistheoretischen Literatur wiederholt mit skeptischen Hypothesen verglichen worden: Beide entzögen sich der empirischen Überprüfung, indem sie sich gegen Gegenbelege immunisierten. Im Falle von VTn bestehe die Immunisierung darin, dass vermeintliche Gegenbelege ungeprüft auf Vertuschungs- oder Täuschungshandlungen der Verschwörer zurückgeführt würden. Eine genauere Rekonstruktion der Täuschungsthese und ein genauerer Blick auf die Immunisierungsthese fördern aber eine Reihe von Disanalogien zutage: Im Unterschied zu skeptischen Hypothesen behaupten VTn das eigene Szenario als real und schreiben die Täuschung nur (...) der Fremdgruppe zu. Damit besteht bei VTn auch nicht die für skeptische Hypothesen typische Symmetrie der Beleglage: Keine Partei diagnostiziert ein Patt, jede weist vielmehr die angeführten Belege der Gegenseite zurück. VTn entziehen die Täuschungsthese auch nicht jeder möglichen Überprüfung, wie es das Szenario des bösen Dämons tut, sondern kommen in unterschiedlichen Graden der Selbstimmunisierung vor. Die epistemischen Defizite von VTn und die Untugenden ihrer Verfechter treten deutlicher hervor, wenn man den Fokus von der Verschwörungsthese auf die Dynamik ihrer Verteidigung und ihre Ähnlichkeiten zu degenerierenden Forschungsprogrammen verschiebt. -/- In the epistemological literature, conspiracy theories (CTs) are often compared with skeptical hypotheses: Both are said to resist empirical refutation by immunising themselves against counterevidence. In the case of CTs, the trick is to explain away alleged counterevidence by cover-ups or deceptive acts on the part of the conspirators. However, a more precise reconstruction of the deception thesis and a closer look at the immunization thesis reveal a number of disanalogies: Unlike skeptical hypotheses, CTs claim their own scenario to be real, while attributing deception only to the outgroup. Correspondingly, CTs do not exhibit the balance of evidence typical of skeptical hypotheses: Neither party considers the evidence to be symmetrical, each rejects the evidence adduced by the opposing party. Unlike the evil demon scenario, the deception thesis in CTs is not entirely uncheckable. Rather, different CTs exhibit varying degrees of self-immunisation. The epistemic deficiencies of CTs and the epistemic vices of their proponents can be better brought out by shifting the focus from a CT’s claim to the dynamics of defending it and the similarities to degenerating research programmes. (shrink)

This collection of papers joins a growing body of work addressing what are arguably some of the most important questions faced in the 21st century; what does it mean to be human and what do we understand by humanity?

According to veridicalism, your beliefs about the existence of ordinary objects are typically true, and can constitute knowledge, even if you are in some global sceptical scenario. Even if you are a victim of Descartes’ demon, you can still know that there are tables, for example. Accordingly, even if you don’t know whether you are in some such scenario, you still know that there are tables. This refutes the standard sceptical argument. But does it solve the sceptical problem posed by (...) that argument? I argue that it does not, because we do not know substantively more about the external world according to veridicalism than we do according to the sceptical argument. Rather, veridicalism merely reformulates what little knowledge we have. I then draw some general conclusions about the nature of the sceptical problem, the formulation of the standard argument, and the significance of this for some other, non-veridicalist strategies. (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)

Many epistemologists believe that the distinction between the genesis and the validity of a belief is a fundamental presupposition of adequate epistemological reflection. In this article it will be argued that the arguments for this majority conviction are not convincing. As an alternative it is suggested that the distin- ction between epistemic and non-epistemic procedures should be regarded as fundamental for epistemology.

This book, the first of its kind, puts forward a novel, unified cognitive account of skeptical doubt. Historically, most philosophers have tried to tackle this difficult topic by directly arguing that skeptical doubt is false. But N. Ángel Pinillos does something different. He begins by trying to uncover the hidden mental rule which, for better or worse, motivates our skeptical inclinations. He then gives an account of the broader cognitive purpose of having and applying this rule. Based on these ideas, (...) he shows how we can give a new response to the traditional problem of global skepticism. He also argues that philosophical skepticism is not just something that comes up during philosophical reflection, as David Hume, Charles Sanders Peirce and other philosophers have urged. Instead, it is of great practical significance. The rule which produces skepticism may itself be operative in certain pathologies such as obsessive-compulsive disorder, in creative endeavors, and in conspiratorial thinking. The rule can also explain some of our reluctance to trust statistical evidence, especially in legal settings. More broadly, this volume aims to breathe new life into a classic problem in philosophy by tackling it from a new perspective and exploring new areas of application. The book will be of interest to philosophers, psychologists and anyone interested in the human capacity to doubt and to question our beliefs. (shrink)

In this Précis, I provide an overview of my Monograph Knowing and Checking: An Epistemological Investigation (Melchior 2019), which is subject to a book symposium organized by the University of Maribor. This volume in Acta Analytica contains contributions by Peter Baumann, Kelly Becker, Marian David, Nenad Miščević, Robert Weston Siscoe, and Danilo Šuster along with my replies.

This article develops a logical (or semantic) response to scepticism about the existence of an external world. Specifically, it is argued that any doubt about the existence of an external world can be proved to be false, but whatever appears to be doubt about the existence of an external world that _cannot_ be proved to be false is nonsense, insofar as it must rely on the assertion of something that is logically impossible. The article further suggests that both G. E. (...) Moore and Ludwig Wittgenstein worked towards the same solution but left their work unfinished. (shrink)

This is a critical notice of Christos Kyriacou and Kevin Wallbridge (eds.), Skeptical Invariantism Reconsidered. New York and London: Routledge, 2021. Pp. x + 324. ISBN 978-0-367-37018-3. It discusses in some detail contributions by Nevin Climenhaga, Christos Kyriacou, Michael Hannon, Kevin Wallbridge, Annalisa Coliva, and Genia Schönbaumsfeld.

Both sensitivity and safety theorists concur that their accounts should be relativized to the same method that one employs in the actual world. However, properly individuating methods has proven to be a tricky matter. In this regard, Nozick (Philosophical Explanations, Harvard University Press, Cambridge, 1981) proposes a Same-Experience-Same-Method Principle: if the experiences associated with two method tokens are the same, they are of the same type of method. This principle, however, has been widely rejected by recent safety and sensitivity theorists. (...) In this paper, I raise an argument in favor of Nozick: not endorsing the principle leads to some rather implausible consequences when certain skeptical scenarios are considered—i.e., scenarios in which skeptical possibilities are ‘close’. Additionally, this argument reveals some important lessons about skepticism in general and the place of modal accounts of knowledge in the internalism/externalism debate. (shrink)

The Cartesian arguments for external world skepticism are usually considered to be significant for at least two reasons: they seem to present genuine paradoxes and that providing an adequate response to these arguments would reveal something epistemically important about knowledge, justification, and/or our epistemic position to the world. Using only premises and reasoning the skeptic accepts, I will show that the most common Cartesian argument for external world skepticism leads to a previously unrecognized self-undermining dilemma: it either leads to a (...) reductio ad absurdum, or to avoid this reductio the skeptic must accept that this argument is epistemically idle—it does not provide any support for external world skepticism. Either way, this Cartesian argument cannot legitimately threaten or even call into question our beliefs about the external world. And thus, either way, this Cartesian argument for external world skepticism is not epistemically significant—it is not a genuine paradox and adequately responding to it need not reveal anything epistemically important. (shrink)

Various theorists contend that we may live in a computer simulation. David Chalmers in turn argues that the simulation hypothesis is a metaphysical hypothesis about the nature of our reality, rather than a sceptical scenario. We use recent work on consciousness to motivate new doubts about both sets of arguments. First, we argue that if either panpsychism or panqualityism is true, then the only way to live in a simulation may be as brains-in-vats, in which case it is unlikely that (...) we live in a simulation. We then argue that if panpsychism or panqualityism is true, then viable simulation hypotheses are substantially sceptical scenarios. We conclude that the nature of consciousness has wide-ranging implications for simulation arguments. (shrink)

Crispin Wright hat die bislang beste Rekonstruktion von Putnams Beweis gegen die skeptische Hypothese vom Gehirn im Tank vorgelegt. Aber selbst in Wrights Fassung hat der Beweis einen Mangel: Er wird mithilfe eines Prädikates wie z.B. "Tiger" geführt und funktioniert nur, wenn man sich darauf verlassen kann, dass es Tiger wirklich gibt. Aber die Skeptikerin bestreitet, über die Existenz von Tigern bescheid zu wissen. Das Problem lässt sich dadurch beheben, dass man den Beweis – statt mit dem extensionalen Begriff der (...) Referenz (wie bei Wright) – mit Intensionen führt. Zudem sollte der Beweis transzendental laufen, also einzig und allein auf den sprachlichen Voraussetzungen beruhen, die auch die Skeptikerin zur Formulierung ihrer Tank-Hypothese benötigt. (shrink)

In this paper, I argue that the ecological approach to perception provides resources to overcome the causal argument against disjunctivism. According to the causal argument, since the brain states that proximally cause the perceptual experience and the corresponding hallucinatory one can be of the same type, there would be no good reason to reject that the perceptual experience and the corresponding hallucinatory experience have fundamentally the same nature. Disjunctivism concerning the nature of the experience would then be false. I identify (...) three assumptions that support the causal argument: the indistinguishability assumption, the linearity assumption, and the duplication assumption. According to the ecological approach to disjunctivism, these assumptions should be rejected, opening up room for a version of disjunctivism that I call 'Ecological Disjunctivism'. Perceptual episodes are extended over time and are supervenient to the organism-environment system. They can be distinguished from the 'corresponding' hallucinations because the former results from a controlled process of attunement to the environment, whereas hallucinations are passive and insensible to the exploratory activities of the perceptual system. Finally, ecological disjunctivism, since it is immune to the causal argument, is more advantageous than negative and positive disjunctivism. (shrink)

In this paper, I offer reasons for thinking that two prominent sceptical arguments in the literature – the underdetermination-based sceptical argument and the closure-based sceptical argument – are less philosophically interesting than is commonly supposed. The underdetermination-based argument begs the question against a non-sceptic and can be dismissed with little fanfare. The closure-based argument, though perhaps not question-begging per se, does rest upon contentious assumptions that a non-sceptic is under no pressure to accept.

According to the idealist, facts about phenomenal experience determine facts about the physical world. Any such view must account for illusions: cases where there is a discrepancy between the physical world and our experiences of it. In this paper, I critique some recent idealist treatments of illusions before presenting my own preferred account. I then argue that, initial impressions notwithstanding, it is actually the realist who has difficulties properly accounting for illusions.

A certain brand of skeptical argument appeals to the thought that our inability to subjectively discriminate between competing hypotheses means that we are unwarranted in believing in either. Externalists respond by pointing out that such arguments depend on an internalist conception of warrant that we would do well to reject. This strategy has been criticised by Crispin Wright who argues that if we pursue the implications of externalism sufficiently far we find that it is ultimately unstable or incoherent. I first (...) rehearse the simple externalist anti-skeptical position. I then present Wright’s argument for the externalist instability, offering a clearer way of understanding its central claim. Finally, I show that the instability in fact arises due to hidden internalist assumptions about evidence and that rid of these assumptions the externalist position is stable after all. (shrink)

The Illusion of Doubt shows that radical scepticism is an illusion generated by a Cartesian picture of our evidential situation—the view that my epistemic grounds in both the ‘good’ and the ‘bad’ cases must be the same. It is this picture which issues both a standing invitation to radical scepticism and ensures that there is no way of getting out of it while agreeing to the sceptic’s terms. The sceptical problem cannot, therefore, be answered ‘directly’. Rather, the assumptions that give (...) rise to it, need to be undermined. These include the notion that radical scepticism can be motivated by the ‘closure’ principle for knowledge, that the ‘Indistinguishability Argument’ renders the Cartesian conception compulsory, that the ‘New Evil Genius Thesis’ is coherent, and the demand for a ‘global validation’ of our epistemic practices makes sense. Once these dogmas are undermined, the path is clear for a ‘realism without empiricism’ that allows us to re-establish unmediated contact with the objects and persons in our environment which an illusion of doubt had threatened to put forever beyond our cognitive grasp. (shrink)

The paper defends Cartesian skepticism by an argument relying on internalism and infallibilism. It argues that this sort of skepticism gives the best explanation of our intuitions and ordinary epistemic practices.

The history of scepticism is assumed by many to be the history of failed responses to a problem first raised by Descartes. While the thought of the ancient sceptics is acknowledged, their principle concern with how to live a good life is regarded as bearing little, if any, relation to the work of contemporary epistemologists. In "Scepticism" Neil Gascoigne engages with the work of canonical philosophers from Descartes, Hume and Kant through to Moore, Austin, and Wittgenstein to show how themes (...) that first emerged in the Hellenistic period are inextricably bound up with the historical development of scepticism. Foremost amongst these is the view that scepticism relates not to the possibility of empirical knowledge but to the possibility of epistemological theory. This challenge to epistemology itself is explored and two contemporary trends are considered: the turn against foundationalist epistemology and towards more naturalistic conceptions of inquiry, and the resistance to this on the part of non-naturalistically inclined philosophers. In contextualizing the debate in this way Gascoigne equips students with a better appreciation of the methodological importance of sceptical reasoning, an analytic understanding of the structure of sceptical arguments, and an awareness of the significance of scepticism to the nature of philosophical inquiry. (shrink)

An orthodox sceptical hypothesis claims that one’s belief that “I am not a brain-in-a-vat (BIV)” (or any other ordinary anti-sceptical belief) is insensitive. A form of sensitivity-based scepticism, can thus be constructed by combining this orthodox hypothesis with the sensitivity principle and the closure principle. Unlike traditional solutions to the sensitivity-based sceptical problem, this paper will propose a new solution—one which does not reject either closure or sensitivity. Instead, I argue that sceptics’ assumption that one’s ordinary anti-sceptical beliefs are insensitive (...) will give rise to self-contradiction. The orthodox sceptical hypothesis is thus revealed to be incoherent and arbitrary. Given that there is no coherent reason to presuppose our ordinary anti-sceptical beliefs to be insensitive, the argument for sensitivity-based scepticism can thus be blocked at a lower epistemological cost. (shrink)

Die klassische bikategoriale Ontologie von Substanzen und Akzidentien ist für die Festlegung der Strukturen menschlichen und tierischen Verhaltens nicht hinreichend, da die Umwelten dieses Verhaltens sich nicht in dieses klassische System einfügen. Wir bieten dementsprechend den Grundriß einer Theorie der besonderen Gebilde, die die Alltagswelten menschlicher und tierischer Verhalten konstituieren. Die Ausgangsüberlegung ist die folgende, Wir sind alle (Schau)spieler, und diese brauchen eine Bühne. Unsere Bühne ist die jeweilige Umwelt, in der wir leben und handeln. Der Terminus ‘Umwelt’ wird hierbei (...) in Analogie zu Husserls Begriff der Lebenswelt verwendet. Er bezeichnet dementsprechend einen strukturierten Teil der Welt, in den sich ein Lebewesen, z.B. ein Mensch, einpaßt. Die Umwelt ist, wenn man so will, demnach die Bühne, auf welcher sich unser Verhalten abspielt. Der Versuch, das Wesen solcher Umwelten ontologisch festzulegen, bringt allerdings ein schwieriges Problem mit sich - ein Problem so alt wie Platons Höhlengleichnis und so neu wie gegenwärtige Reflexionen amerikanischer Philosophen zur Metaphysik der virtuellen Realität und zum Gedankenexperiment des Gehirns im Tank. Es gibt nämlich in manchen Fällen grobe Inkonsistenzen zwischen (1) der Umwelt, wie wir sie uns gerade vorstellen, und (2) der Umwelt als Bestandteil der wirklichen Welt. Das Problem, zwischen diesen beiden Umweltklassen einen Ausgleich zu finden, wird im letzten Teil des Aufsatzes behandelt. (shrink)

There are brains in vats (BIVs) in the actual world. These “cerebral organoids” are roughly comparable to the brains of three-month-old foetuses, and conscious cerebral organoids seem only a matter of time. Philosophical interest in conscious cerebral organoids has thus far been limited to bioethics, and the purpose of this paper is to discuss cerebral organoids in an epistemological context. In doing so, I will argue that it is now clear that there are close possible worlds in which we are (...) BIVs. Not only does this solidify our intuitive judgement that we cannot know that we are not BIVs, but it poses a fundamental problem for both the neo-Moorean (i.e. safety-based) antisceptical strategy, which purports to allow us to know that we aren’t BIVs, and the safety condition on knowledge itself. Accordingly, this case is especially instructive in illustrating just how epistemologically relevant empirical developments can be. (shrink)