I focus on a key argument for global external world scepticism resting on the underdetermination thesis: the argument according to which we cannot know any proposition about our physical environment because sense evidence for it equally justifies some sceptical alternative (e.g. the Cartesian demon conjecture). I contend that the underdetermination argument can go through only if the controversial thesis that conceivability is per se a source of evidence for metaphysical possibility is true. I also suggest a reason to doubt that (...) conceivability is per se a source of evidence for metaphysical possibility, and thus to doubt the underdetermination argument. (shrink)

Epistemologists understand radical skepticism as arising from two principles: Closure and Underdetermination. Both possess intuitive prima facie support for their endorsement. Understanding how they engender skepticism is crucial for any reasonable anti-skeptical attempt. The contemporary discussion has focused on elucidating the relationship between them to ascertain whether they establish distinct skeptical questions and which of the two constitutes the ultimately fundamental threat. Major contributions to this debate are due to Brueckner, Cohen, and Pritchard. This contribution aims at defending Brueckner’s contention (...) that underdetermination expresses the fundamental skeptical threat and that the closure-based argument can ultimately be reduced to it, at least concerning skeptical contexts. This will be achieved by undermining Cohen’s objections to Brueckner on both counts. Cohen’s argument endorses a picture of evidential underdetermination, which, while apt for non-skeptical contexts, cannot be applied to radical skepticism. A comparison with a case of scientific underdetermination is developed to argue for this idea. Our argument is then applied to the principle equivalence issue and to objections against it. It is then shown how this analysis possesses a distinctive effect on our understanding of the skeptical threat and the assessment of successful anti-skeptical strategies. (shrink)

According to epistemological disjunctivism (ED), in paradigmatic cases of perceptual knowledge, a subject, S, has perceptual knowledge that p in virtue of being in possession of reasons for her belief that p which are both factive and reflectively accessible to S. It has been argued that ED is better placed than both knowledge internalism and knowledge externalism to undercut underdetermination-based skepticism. I identify several principles that must be true if ED is to be uniquely placed to attain this goal. After (...) that, I use those principles to formulate a diachronic skeptical argument. This argument yields the counterintuitive conclusion that understanding a global skeptical hypothesis is all it takes for a rational subject to lose all her perceptual knowledge of the world. Next, I show that a popular Austinian move must reject one or another of the principles that underlie ED. I close by delineating a novel strategy that can block the diachronic skeptical argument while preserving all the principles. The key idea is that perceptual knowledge is grounded in primitive, perceptual and recognitional abilities. This view sheds new light on some puzzling features of global skepticism that have been noted by Descartes and Hume, among others. (shrink)

Modal epistemologies that rely on a fallibilism about modal claims have been gaining traction over the years. This paper critically discusses the accounts of Kung (2009; 2010; 2016) and Dohrn (2018; 2019; 2020) and argues that they are invariably susceptible to being read as entailing claims of epistemic possibility. Both Kung and Dohrn seek to ground modal intuitions on non-modal ones, and primarily appeal to the modalizing capacity of imagination to aid in the discovery of modal truths. However, insofar as (...) inference from non-modal imagination to modal truths remains fallible, then no non-ad hoc distinction can be made between substantiation of fallible metaphysically modal claims and infallible epistemically modal ones. This is because, barring an agent’s infallible knowledge of modal truths, how these truths are asserted must attend the agent’s imperfect epistemic access thereof, therefore entailing claims of modality consistent with her epistemic state – i.e., claims of epistemic possibility. If modal epistemologies in general non-modally ground their modal assertions in this fallible fashion, then they seem inevitably interpretable in terms of epistemic possibility as opposed to some non-epistemic reading of metaphysical possibility. (shrink)

My topic is moderate modal skepticism in the spirit of Peter van Inwagen. Here understood, this is a conservative version of modal empiricism that severely limits the extent to which an ordinary agent can reasonably believe “exotic” possibility claims. I offer a novel argument in support of this brand of skepticism: modal skepticism grounds an attractive (and novel) reply to Humean skepticism. Thus, I propose that modal skepticism be accepted on the basis of its theoretical utility as a tool for (...) dissolving philosophical paradox. (shrink)

Radical skepticism relies on the hypothesis that one could be completely cut off from the external world. In this paper, I argue that this hypothesis can be rationally motivated by means of a conceivability argument. Subsequently, I submit that this conceivability argument does not furnish a good reason to believe that one could be completely cut off from the external world. To this end, I show that we cannot adequately conceive scenarios that verify the radical skeptical hypothesis. Attempts to do (...) so fall prey to one or another of three pitfalls: they end up incomplete, reveal a deep contradiction or recreate a non-skeptical hypothesis. I use these results to improve upon Pritchard’s recent attempt at undercutting radical skepticism. (shrink)

What epistemic defect needs to show up in a skeptical scenario if it is to effectively target some belief? According to the false belief account, the targeted belief must be false in the skeptical scenario. According to the competing ignorance account, the targeted belief must fall short of being knowledge in the skeptical scenario. This paper argues for two claims. The first is that, contrary to what is often assumed, the ignorance account is superior to the false belief account. The (...) second is that the ignorance account ultimately hobbles the skeptic. It does so for two reasons. First, when this account is joined with either a closure-based skeptical argument or a skeptical underdetermination argument, the best the skeptic can do is show that we don’t know that we know. And second, the ignorance account directly implies the maligned KK principle. (shrink)

What is the role of sceptical scenarios—dreams, evil demons, brains in a vat—in scep- tical arguments? According to the error view, sceptical scenarios illustrate the possibil- ity of massive falsity in one’s beliefs, whereas according to the ignorance view, they illustrate the possibility of massive ignorance not necessarily due to falsity. In this paper, the ignorance view is defended by surveying the arguments in favour of it and by replying to two pressing objections against it. According to the first objection, (...) the ignorance view illicitly introduces the kk-principle into sceptical arguments. In reply I argue that kk is not less plausible than its main rival, the closure principle. According to the second objection, relying on veridical ignorance-possibilities contradicts the transparency of belief. In reply I introduce a version of transparency that is consistent with the ignorance view. (shrink)

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