Abstract

Chapter 3 highlights an important epistemological implication of the view developed so far—which is that the inclusion of an autonomous belief condition on propositional knowledge implies that knowledge can be defeated in ways other than via the standard modes of rebutting and undercutting defeat. An account of two types of what I call ‘heteronomous defeat’ for propositional knowledge is developed and defended: one on which propositional knowledge is defeated when the subject acquires a belief that either indicates the target belief is epistemically heteronymous (i.e. Type 1) or calls into doubt the reliability of the subject’s belief-forming process as one that would (reliably enough) result in an epistemically autonomous belief (i.e. Type 2). Recognizing heteronomous defeat as a genuine form of knowledge defeat fits snugly with the wider idea that knowledge defeaters, as such, are indicators of ignorance.