Abstract

According to the closure-based radical skeptical argument, it is impossible for us to have knowledge of the majority of everyday propositions because we can’t have knowledge of the denials of the skeptical hypotheses they entail (Pritchard 96). In Chapter 6 of his book Epistemology, Duncan Pritchard describes a response to this argument which uses the sensitivity principle to deny the closure principle, thereby defeating the radical skeptic’s argument. Despite Pritchard’s concerns with this solution, denying the closure principle using the sensitivity principle is a plausible method of defeating the skeptic. I respond to each of his three objections in turn. First, I argue that the reason the closure principle seems so intuitively plausible (despite being false) is that we tend to consider obvious entailments, rather than skeptical hypotheses, when considering the closure principle. Unlike the skeptical hypotheses, we can know the denial of the obvious entailments because those beliefs are sensitive. Second, I will explain why not allowing for inductive knowledge is no reason to reject the sensitivity principle, as true belief gained by induction can be considered rational belief, rather than knowledge. Finally, I will argue that the sensitivity principle can, indeed, provide the necessary counterexamples to the closure principle— something Pritchard denies because he thinks the sensitivity principle demands an evaluation process that cannot be applied when considering skeptical scenarios. However, with a proper understanding of what the sensitivity principle requires, we can use it to deny the closure principle. This paper endeavours to demonstrate that Pritchard’s concerns are not sufficient reason to reject the sensitivity principle as a solution to closure-based radical skepticism.