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)

Philosophy and Phenomenological Research, Volume 104, Issue 2, Page 434-453, March 2022.

I argue for the unexceptionality of evidence about what rationality requires. Specifically, I argue that, as for other topics, one’s total evidence can sometimes support false beliefs about this. Despite being prima facie innocuous, a number of philosophers have recently denied this. Some have argued that the facts about what rationality requires are highly dependent on the agent’s situation and change depending on what that situation is like. (Bradley 2019). Others have argued that a particular subset of normative truths, those (...) concerning what epistemic rationality requires, have the special property of being ‘fixed points’—it is impossible to have total evidence that supports false belief about them. (Smithies 2012; Titelbaum 2015). Each of these kinds of exceptionality permits a solution to downstream theoretical problems that arise from the possibility of evidence supporting false belief about requirements of rationality. However, as I argue here, they incur heavy explanatory burdens that we should avoid. (shrink)

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. (shrink)

Epistemologists often appeal to the idea that a normative theory must provide useful, usable, guidance to argue for one normative epistemology over another. I argue that this is a mistake. Guidance considerations have no role to play in theory choice in epistemology. I show how this has implications for debates about the possibility and scope of epistemic dilemmas, the legitimacy of idealisation in Bayesian epistemology, uniqueness versus permissivism, sharp versus mushy credences, and internalism versus externalism.

I develop a new version of the ordinary language response to skepticism. My version is based on premises about the practical functions served by our epistemic words. I end by exploring how my argument against skepticism is interestingly non-circular and philosophically valuable.

In this paper I argue that Cartesian skepticism about the external world is self-defeating. The Cartesian skeptic holds that we are not justified in believing claims about the external world on the grounds that we cannot rule out the possibility of our being in a radical skeptical scenario. My argument against this position builds upon a critique of Wilson in Analysis, 72, 668–673. Wilson argues that the Cartesian’s skeptical reasoning commits him to mental state skepticism and that this undermines his (...) ability to claim that he is truly skeptical about the external world. I show that Wilson’s argument does not succeed. She is correct that the Cartesian is committed to mental state skepticism. However, she is mistaken in thinking that there is anything incoherent about combining the Cartesian position that one ought to doubt external world claims with doubt about whether one is in fact such a skeptic. I propose an alternative explanation as to why mental state skepticism proves to be the Cartesian’s undoing. I suggest that mental state skepticism leads to epistemic skepticism and that this undermines the Cartesian’s position that belief about the external world is unjustified. (shrink)

I argue that certain species of belief, such as mathematical, logical, and normative beliefs, are insulated from a form of Harman-style debunking argument whereas moral beliefs, the primary target of such arguments, are not. Harman-style arguments have been misunderstood as attempts to directly undermine our moral beliefs. They are rather best given as burden-shifting arguments, concluding that we need additional reasons to maintain our moral beliefs. If we understand them this way, then we can see why moral beliefs are vulnerable (...) to such arguments while mathematical, logical, and normative beliefs are not—the very construction of Harman-style skeptical arguments requires the truth of significant fragments of our mathematical, logical, and normative beliefs, but requires no such thing of our moral beliefs. Given this property, Harman-style skeptical arguments against logical, mathematical, and normative beliefs are self-effacing; doubting these beliefs on the basis of such arguments results in the loss of our reasons for doubt. But we can cleanly doubt the truth of morality. (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.