Michael Blome-Tillmann

Certain puzzling cases have been discussed in the literature recently which appear to support the thought that knowledge can be obtained by way of deduction from a falsehood; moreover, these cases put pressure, prima facie, on the thesis of counter closure for knowledge. We argue that the cases do not involve knowledge from falsehood; despite appearances, the false beliefs in the cases in question are causally, and therefore epistemologically, incidental, and knowledge is achieved despite falsehood. We also show that the principle of counter closure, and the concomitant denial of knowledge from falsehood, is well motivated by considerations in epistemological theory--in particular, by the view that knowledge is first in the epistemological order of things.

The paper gives an a priori argument for the view that knowledge is unanalysable. To establish this conclusion I argue that warrant, i.e. the property, whatever precisely it is, which makes the difference between knowledge and mere true belief, entails both truth and belief and thus does not exist as a property distinct from knowledge: all and only knowledge can turn a true belief into knowledge. The paper concludes that the project of trying to find a condition distinct from knowledge that is necessary and together with truth and belief sufficient for knowledge must be doomed to failure.

In this chapter, I produce counterexamples to Presuppositional Epistemic Contextualism (PEC), a view about the semantics of ‘knowledge’-ascriptions that I have argued for elsewhere. According to PEC, the semantic content of the predicate ‘know’ at a context C is partly determined by the speakers’ pragmatic presuppositions at C. The problem for the view that I shall be concerned with here arises from the fact that pragmatic presuppositions are sometimes known to be true by the speakers who make them: hence the Problem of Known Presuppositions. After discussing several unsuccessful ways to solve the problem, I propose the addition of a new Lewisian rule of proper ignoring to the semantics of PEC--namely, the Rule of Evidence-Based Ignoring. If the proposed account succeeds, the Problem of Known Presuppositions has a straightforward solution within the framework of PEC.