Evidence does not equal knowledge

Timothy Williamson has argued that a person S ’s total evidence is constituted solely by propositions that S knows. This theory of evidence entails that a false belief can not be a part of S ’s evidence base for a conclusion. I argue by counterexample that this thesis (E = K for now) forces an implausible separation between what it means for a belief to be justified and rational from one’s perspective and what it means to base one’s beliefs on the evidence. Furthermore, I argue that E = K entails the implausible result that there are cases in which a well-evidenced belief necessarily can not serve as evidence for a further proposition.