Two skeptical arguments or only one?

The first step in responding to the challenge of external world skepticism is to get clear on the structure of the skeptic’s argument. The most prominent varieties of skeptical arguments either rely on closure principles or underdetermination principles. The relationship between these two sorts of arguments is contentious. Some argue that these arguments can independently motivate skepticism. Others argue that they are really equivalent. I argue that although these two arguments are distinct, their independence is not as obvious as some have thought. The fact that these arguments are not equivalent is important because skeptical arguments that appeal to underdetermination principles cannot be refuted by simply denying closure. So, the strategy for responding to skepticism offered by Nozick/Dretske does not seem an adequate solution.     

The theoretical diagnosis of skepticism

Radical skepticism about the external implies that no belief about the external is even prima facie justified. A theoretical reply to skepticism has four stages. First, show which theories of epistemic justification support skeptical doubts (show which theories, given other reasonable assumptions, entail skepticism). Second, show which theories undermine skeptical doubts (show which theories, given other reasonable assumptions, do not support the skeptic’s conclusion). Third, show which of the latter theories (which non-skeptical theory) is correct, and in so doing show that all of the rival theories of justification, skeptical and non-skeptical alike, are mistaken. Fourth, explain why skeptical doubts are sometimes (or sometimes merely seem) intuitive, and thereby accommodate skeptical doubts without capitulation. Michael Williams has pioneered the very idea of a theoretical reply. A theoretical diagnosis consists in just the first two stages. An adequate reply, which is correct at each stage, would rebut the skeptic entirely. Williams’ own reply, I argue, is inadequate. I offer in its place an exhaustive and accurate diagnosis of skepticism. I distinguish four kinds of skepticism and five theories of justification. I then show which theories do, and which theories do not, support which kinds of skepticism.     

‘That’-Clauses and Non-nominal Quantification

This paper argues that ‘that’-clauses are not singular terms (without denying that their semantical values are propositions). In its first part, three arguments are presented to support the thesis, two of which are defended against recent criticism. The two good arguments are based on the observation that substitution of ‘the proposition that p’ for ‘that p’ may result in ungrammaticality. The second part of the paper is devoted to a refutation of the main argument for the claim that ‘that’-clauses are singular terms, namely that this claim is needed in order to account for the possibility of quantification into ‘that’-clause position. It is shown that not all quantification in natural languages is quantification into the position of singular terms, but that there is also so-called ‘non-nominal quantification’. A formal analysis of non-nominal quantification is given, and it is argued that quantification into ‘that’-clause position can be treated as another kind non-nominal quantification.     

Darwin’s solution to the species problem

Biologists and philosophers that debate the existence of the species category fall into two camps. Some believe that the species category does not exist and the term ‘species’ should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the species category exists. This paper offers a different approach to the species problem. We should be skeptical of the species category, but not skeptical of the existence of those taxa biologists call ‘species.’ And despite skepticism over the species category, there are pragmatic reasons for keeping the word ‘species.’ This approach to the species problem is not new. Darwin employed a similar strategy to the species problem 150 years ago.     

Knowledge and deductive closure

The question whether epistemological concepts are closed under deduction is an important one since many skeptical arguments depend on closure. Such skepticism can be avoided if closure is not true of knowledge (or justification). This response to skepticism is rejected by Peter Klein and others. Klein argues that closure is true, and that far from providing the skeptic with a powerful weapon for undermining our knowledge, it provides a tool for attacking the skeptic directly. This paper examines various arguments in favor of closure and Klein's attempted use of closure to refute skepticism. Such a refutation of skepticism is mistaken. But the closure principle is in any case false, so the skepticism that depends on it is undermined. The appeal of the closure principle derives from a failure to recognize an important feature of our epistemological concepts, namely, their context relativity.     

Skeptical Appeal: The Source‐Content Bias

Radical skepticism is the view that we know nothing or at least next to nothing. Nearly no one actually believes that skepticism is true. Yet it has remained a serious topic of discussion for millennia and it looms large in popular culture. What explains its persistent and widespread appeal? How does the skeptic get us to doubt what we ordinarily take ourselves to know? I present evidence from two experiments that classic skeptical arguments gain potency from an interaction between two factors. First, people evaluate inferential belief more harshly than perceptual belief. Second, people evaluate inferential belief more harshly when its content is negative (i.e., that something is not the case) than when it is positive (i.e., that something is the case). It just so happens that potent skeptical arguments tend to focus our attention on negative inferential beliefs, and we are especially prone to doubt that such beliefs count as knowledge. That is, our cognitive evaluations are biased against this specific combination of source and content. The skeptic sows seeds of doubt by exploiting this feature of our psychology.     

A Butterfly Dream in a Brain in a Vat

Zhuangzi’s Butterfly Dream story can be read as a skeptical response to the Cartesian Cogito, ergo sum solution, for it presents I exist as fundamentally unprovable, on the grounds that the notion about “I” that it is guaranteed to refer to something existing, which Descartes seems to assume, is unwarranted. The modern anti-skepticism of Hilary Putnam employs a different strategy, which seeks to derive the existence of the world not from some “indubitable” truth such as the existence of myself, but from the meaning of some particular assertion I make. In this paper, I argue, however, that Putnam’s argument fails to deliver on the promise of showing the self-refuting nature of the skeptical hypothesis, as it relies on a double use of “I”, a fallacy of equivocation, reflecting an unsolved tension between the argument’s general premise, which is rather Zhuangzian in spirit, and his unwitting adoption of that unwarranted notion about “I”. I try to show further that the skepticism in Zhuangzi’s Butterfly Dream not only can be used to refute the proofs of the existence of the empirical I, but also is effective against accounts concerning the existence of the transcendental I.     

Intensional Specifications of Truth-Conditions: ‘Because’, ‘In Virtue of’, and ‘Made True By…’

Although a number of truth theorists have claimed that a deflationary theory of ‘is true’ needs nothing more than the uniform implication of instances of the theorem ‘the proposition that p is true if and only if p’, reflection shows that this is inadequate. If deflationists can’t support the instances when replacing the biconditional with ‘because’, then their view is in peril. Deflationists sometimes acknowledge this by addressing, occasionally attempting to deflate, ‘because’ and ‘in virtue of’ formulas and their close relatives. I examine what I take to be the most promising deflationist moves in this direction and argue that they fail.     

Paying the cost of skeptical theism

In this paper I show that two arguments for the inconsistency of skeptical theism fail. After setting up the debate in “Introduction” section, I show in “The initial debate” section why Mylan Engel’s argument (Engel 2004) against skeptical theism does not succeed. In “COST” section I strengthen the argument so that it both avoids my reply to Engel and parallels Jon Laraudogoitia’s argument against skeptical theism (Laraudogoitia 2000). In “COST*” section, I provide three replies—one by an evidentialist theist, one by a closure-denying theist, and one by a necessitarian theist, and argue that the necessitarian’s reply successfully rebuts the inconsistency charge. I conclude that skeptical theism which accepts God’s necessary existence is immune to both kinds of arguments for its inconsistency.     

Skeptical Theism and God’s Commands

According to Michael Almeida and Graham Oppy, adherents of skeptical theism will find their sense of moral obligation undermined in a potentially ‘appalling’ way. Michael Bergmann and Michael Rea disagree, claiming that God’s commands provide skeptical theists with a source of moral obligation that withstands the skepticism in skeptical theism. I argue that Bergmann and Rea are mistaken: skeptical theists cannot consistently rely on what they take to be God’s commands.

Skeptical Parasitism and the Continuity Argument

Abstract: Recent literature on skepticism has raised a nearly univocal voice in condemning skeptical argumentation on the grounds that such argumentation necessarily involves our adopting some nonordinary or unnatural perspective. Were this really so, then skeptical conclusions would not speak to us in the way in which skeptics think they do; we would be “insulated” from any such conclusions. I argue that skeptical argumentation need not rely on any nonordinary or unnatural standards. Rather, the skeptic's procedure is to offer a critique from within. Having given my argument for this claim (which I call the Continuity Argument), I consider and respond to two important objections. I conclude that the skeptic has a powerful meta‐argument to be deployed in defending the legitimacy of his skeptical conclusions against the slings and arrows of (those I call) the half‐true theorists.     

Causation as a Philosophical Relation in Hume

By giving the proper emphasis to both radical skepticism and naturalism as two independent standpoints in Hume, I wish to propose a more satisfactory account of some of the more puzzling Humean claims on causation. I place these claims alternatively in either the philosophical standpoint of the radical skeptic or in the standpoint of everyday and scientific beliefs. I characterize Hume's radical skeptical standpoint in relation to Hume's perceptual model of the traditional theory of ideas, and I argue that Hume's radical skeptical argument concerning our causal inferences is inextricably linked to his skeptical argument concerning our idea of a necessary connection between cause and effect. I discuss Hume's naturalistic account of the origin of our idea of necessity and offer a new reading of Hume's two "definitions" of cause. I argue along the way against central aspects of two opposing styles of interpretation—Norman Kemp Smith's and Annette Baier's, on the one hand, and Robert Fogelin's, on the other—that in my view do not appreciate the mutual autonomy of radical skepticism and naturalism in Hume.     

Defeating the self-defeat argument for phenomenal conservativism

Michael Huemer has argued for the justification principle known as phenomenal conservativism by employing a transcendental argument that claims all attempts to reject phenomenal conservativism ultimately are doomed to self-defeat. My contribution presents two independent arguments against the self-defeat argument for phenomenal conservativism after briefly presenting Huemer’s account of phenomenal conservativism and the justification for the self-defeat argument. My first argument suggests some ways that philosophers may reject Huemer’s premise that all justified beliefs are formed on the basis of seemings. In the second argument I contend that phenomenal conservativism is not a well-motivated account of internal justification, which is a further reason to reject the self-defeat argument. Consequently, the self-defeat argument fails to show that rejecting phenomenal conservativism inevitably leads one to a self-defeating position.     

Modal skepticism and counterfactual knowledge

Timothy Williamson has recently proposed to undermine modal skepticism by appealing to the reducibility of modal to counterfactual logic (Reducibility). Central to Williamson’s strategy is the claim that use of the same non-deductive mode of inference (counterfactual development, or CD) whereby we typically arrive at knowledge of counterfactuals suffices for arriving at knowledge of metaphysical necessity via Reducibility. Granting Reducibility, I ask whether the use of CD plays any essential role in a Reducibility-based reply to two kinds of modal skepticism. I argue that its use is entirely dispensable, and that Reducibility makes available replies to modal skeptics which show certain propositions to be metaphysically necessary by deductive arguments from premises the modal skeptic accepts can be known.     

Epistemic closure, skepticism and defeasibility

Those of us who have followed Fred Dretske??s lead with regard to epistemic closure and its impact on skepticism have been half-wrong for the last four decades. But those who have opposed our Dretskean stance, contextualists in particular, have been just wrong. We have been half-right. Dretske rightly claimed that epistemic status is not closed under logical implication. Unlike the Dretskean cases, the new counterexamples to closure offered here render every form of contextualist pro-closure maneuvering useless. But there is a way of going wrong under Dretske??s lead. As the paper argues, Cartesian skepticism thrives on closure failure in a way that is yet to be acknowledged in the literature. The skeptic can make do with principles which are weaker than the familiar closure principles. But I will further claim that this is only a momentary reprieve for the skeptic. As it turns out, one of the weaker principles on which a skeptical modus tollens must rest can be shown false.     

Bundling Hume with Kripkenstein

It is argued that the intuition driving Kripke’s famous version of Wittgenstein’s meaning skepticism is precisely the one that prompted Hume to despair of his bundle theory of the self: there are no necessary connections between distinct mental states. This interpretation is shown to throw light on Wittgenstein’s notorious idea that all proofs “create concepts.”

Wittgenstein has invented a new form of skepticism. Personally I am inclined to regard it as the most radical and original skeptical problem that philosophy has seen to date[.] – Saul Kripke

     

Evidentialism and skeptical arguments

Cartesian skepticism about epistemic justification (??skepticism??) is the view that many of our beliefs about the external world??e.g., my current belief that I have hands??aren??t justified. I examine the two most influential arguments for skepticism??the Closure Argument and the Underdetermination Argument??from an evidentialist perspective. For both arguments it??s clear which premise the anti-skeptic must deny. The Closure Argument, I argue, is the better argument in that its key premise is weaker than the Underdetermination Argument??s key premise. Next I examine ways of motivating each argument??s key premise. I argue that attempts to motivate them which appeal to one??s having the same evidence in skeptical scenarios, to skeptical hypotheses?? alleged ability to explain our evidence just as well as real world hypotheses, or to the fact that if skeptical scenarios were true everything would appear just as it does all fail to provide any motivation for the premises or for skepticism. But I close by considering a different argument for the key premises and skepticism that lacks the central defect of these other arguments. Future work on skepticism should focus on this final argument at the expense of the others.     

Skepticism Between Excessiveness and Idleness

Abstract: Skepticism seems to have excessive consequences: the impossibility of successful enquiry and differentiated judgment. Yet if skepticism could avoid these consequences, it would seem idle. I offer an account of moderate skepticism that avoids both problems. Moderate skepticism avoids excessiveness because skeptical reflection and ordinary enquiry are immune from one another: a skeptical hypothesis is out of place when raised with in an ordinary enquiry. Conversely, the result of an ordinary enquiry cannot be used to disprove skepticism. This 'immunity' can be explained by theories such as contextualism, or sensitive invariantism. Moderate skepticism avoids idleness, because it can eliminate dogmatic elements from our commitments. An analogy is used to illustrate this: Consider someone who is rootless—someone who doesn't have a home. She won't take this conclusion to undermine her judgment that she is flying home for the holidays—even if she is sleeping in the guest bedroom. Similarly, a skeptic won't take the skeptical conclusion to undermine ordinary claims to know. Yet concluding that one is rootless is significant: it can shape one's commitments; for instance it can check one's nationalism. Similarly, accepting the skeptical conclusion is significant; it can undermine dogmatic commitments and ultimately bring about intellectual catharsis.     

Practical knowledge and the subjectivity of truth in Kant and Kierkegaard: The cover of skepticism

Kant developed a distinctive method of philosophical argumentation, the method of transcendental argumentation, which continues to have contemporary philosophical promise. Yet there is considerable disagreement among Kant's interpreters concerning the aim of transcendental arguments. On ambitious interpretations, transcendental arguments aim to establish certain necessary features of the world from the conditions of our thinking about or experiencing the world; they are world‐directed. On modest interpretations, transcendental arguments aim to show that certain beliefs have a special status that renders them invulnerable to skeptical doubts; they are belief‐directed. This paper brings Kierkegaard's thesis of the “subjectivity of truth” to bear on these questions concerning the aim of transcendental arguments. I focus on Kant's argument for the postulate of God's existence in his Critique of Practical Reason and show that Kierkegaard's thesis of the subjectivity of truth can help us construe the argument as both belief and world directed. Yet I also argue that Kierkegaard's thesis of the subjectivity of truth can help us understand the source of our dissatisfaction with Kant's transcendental arguments: It can help us understand that dissatisfaction as an expression of what Stanley Cavell calls the “cover of skepticism,” the conversion of metaphysical finitude into intellectual lack.