Externalism, skepticism, and the problem of easy knowledge

The paper deals with a version of the principle that a belief source can be a knowledge source only if the subject knows that it is reliable. I argue that the principle can be saved from the main objections that motivate its widespread rejection: the claim that it leads to skepticism, the claim that it forces us to accept counterintuitive knowledge ascriptions and the claim that it is incompatible with reliabilist accounts of knowledge. I argue that naturalist epistemologists should reject these claims. I introduce my treatment of the principle by considering the analogous situation posed by the closure principle.