Consider the skeptic about the external world. Let’s straightaway concede to such a skeptic that perception gives us no conclusive or certain knowledge about our surroundings. Our perceptual justification for beliefs about our surroundings is always defeasible—there are always possible improvements in our epistemic state which would no longer support those beliefs. Let’s also concede to the skeptic that it’s metaphysically possible for us to have all the experiences we’re now having while all those experiences are false. Some philosophers dispute (...) this, but I do not. The skeptic I want to consider goes beyond these familiar points to the much more radical conclusion that our perceptual experiences can’t give us any knowledge or even justification for believing that our surroundings are one way rather than another. (shrink)

Princeton University Press, 1974. This book is out of print, but can be downloaded as a pdf file (5 MB).

I argue that its appearing to you that P does not provide justification for believing that P unless you have independent justification for the denial of skeptical alternatives – hypotheses incompatible with P but such that if they were true, it would still appear to you that P. Thus I challenge the popular view of ‘dogmatism,’ according to which for some contents P, you need only lack reason to suspect that skeptical alternatives are true, in order for an experience as (...) of P to justify belief that P. I pursue three lines of objection to dogmatism, having to do with probabilistic reasoning, considerations of future or hypothetically available justification, and epistemic circularity. I briefly sketch a fall-back position which avoids the problems raised. (shrink)

The second part of the book presents an alternative beyond the historical positions of Part I, one that defends a virtue epistemology combined with epistemic ...

The dominant response to this problem of the criterion focuses on the alleged requirement that we need to know a belief source is reliable in order for us to acquire knowledge by that source. Let us call this requirement, “The KR principle”.

Recent discussion of Vogel-style “bootstrapping” scenarios suggests that they provide counterexamples to a wide variety of epistemological theories. Yet it remains unclear why it’s bad for a theory to permit bootstrapping, or even exactly what counts as a bootstrapping case. Going back to Vogel's original bootstrapping example, I note that an agent who could gain justification through the method Vogel describes would have available a “no-lose investigation”: an investigation that can justify a proposition but has no possibility of undermining it. (...) The main suggestion of this article is that an epistemological theory should not permit no-lose investigations. I identify necessary and sufficient conditions for such investigations, then explore epistemological theories that rule them out. If we want to avoid both skepticism and no-lose investigations, we must eschew either Closure or epistemic externalism. (shrink)