Skeptical Arguments and Deep Disagreement

This paper provides a reinterpretation of some of the most influential skeptical arguments, Agrippa’s trilemma, meta-regress arguments, and Cartesian external world skepticism. These skeptical arguments are reasonably regarded as unsound arguments about the extent of our knowledge. However, reinterpretations of these arguments tell us something significant about the preconditions and limits of persuasive argumentation. These results contribute to the ongoing debates about the nature and resolvability of deep disagreement. The variety of skeptical arguments shows that we must distinguish different types of deep disagreement. Moreover, the reinterpretation of skeptical arguments elucidates that deep disagreement cannot be resolved via argumentation.

Sextus and External World Skepticism

Chapter 14 discusses the scope of Pyrrhonian skepticism and how it compares with the scope of Cartesian skepticism, with a focus on external world skepticism. At least three general views have been held. First, some commentators think that Pyrrhonian skepticism is less extensive than Cartesian skepticism is. Secondly, Descartes denies that there is a difference in the scopes of ancient and Cartesian skepticism. Thirdly, Hegel thinks that ancient skepticism is more extensive than the skepticism from Descartes’s day to his own is. This chapter argues that the Pyrrhonian skeptics and the Cyrenaics countenance external world skepticism in a recognizable sense. Hence, contrary to a familiar view, Descartes is not the first philosopher to expound external world skepticism.

Introduction

This chapter outlines the main themes of the essays that follow. It also occasionally corrects or clarifies them, and sometimes it discusses more recent literature than they do. One central theme is cognitive conditions and their contents. For example, is epistêmê knowledge as it is conceived of nowadays? Are doxa and dogma belief as it is conceived of nowadays? This chapter also asks whether Plato and/or Aristotle countenances some version of a Two Worlds Theory; and whether ancient skeptics countenance subjective states and/or external world skepticism. It also explains some key distinctions used throughout, such as that between concept and conception.

Revisiting Moore’s Anti-Skeptical Argument in “Proof of an External World”

This paper argues that we should reject G. E. Moore’s anti-skeptical argument as it is presented in “Proof of an External World.” However, the reason I offer is different from traditional objections. A proper understanding of Moore’s “proof” requires paying attention to an important distinction between two forms of skepticism. I call these Ontological Skepticism and Epistemic Skepticism. The former is skepticism about the ontological status of fundamental reality, while the latter is skepticism about our empirical knowledge. Philosophers often assume that Moore’s response to “external world skepticism” deals exclusively with the former, not the latter. But this is a mistake. I shall argue that Moore’s anti-skeptical argument targets an ontological form of skepticism. Thus, the conclusion is an ontological claim about fundamental reality, while the premises are epistemic claims. If this is correct, then the conclusion outstrips the scope of its premises and proves too much.

The Appearance of Skepticism: Possibility, Conceivability and Infinite Ascent

The paper articulates a novel strategy against external world skepticism. It shows that a modal assumption of the skeptical argument cannot be justified.

Austin and the Scope of Our Knowledge

In ordinary circumstances in which we know there is a goldfinch on a branch in the garden, do we know that the thing on the branch isn’t stuffed? Austin’s methodology is perfectly compatible with holding both that we do and that we wouldn’t know it’s a goldfinch if we didn’t. Moreover, Austin’s methodology supports the claim that if we had no information whatsoever about whether it is stuffed, we wouldn’t know the thing on the branch is a goldfinch. Finally, Mark Kaplan’s claim that P is part of your evidence if and only if you know that P leaves him with good reason to agree that in ordinary circumstances, you do know that the goldfinch isn’t stuffed. This result suggests a distinctive way of approaching arguments for external world skepticism with the structure of the so-called Argument from Ignorance. And it highlights just how much can be learned from approaching epistemological issues in an Austinian spirit.

A Sellarsian Transcendental Argument against External World Skepticism

This paper investigates the relation between what James Conant has called Kantian and Cartesian varieties of skepticism. It is argued that a solution to the most prominent example of a Kantian variety of skepticism, i.e. Kripkensteinian skepticism about rule-following and meaning, can be found in the works of Wilfrid Sellars. It is then argued that, on the basis of that very same solution to the Kantian problematic of rule-following and meaning, a novel argument against external world skepticism can be formulated. This argument takes the shape of a transcendental argument, which is reminiscent of Hilary Putnam’s infamous argument against the brain-in-a-vat hypothesis, but is, as is argued, superior to it in certain respects.