Abstract
Sven Rosenkranz’s Justification as Ignorance shows how a strongly internalist conception of justification can be derived from a strongly externalist conception of knowledge, given an identification of justification with second-order ignorance and a set of structural principles concerning knowing and being in a position to know. Among these principles is an epistemic analogue of the Geach modal schema which states that one is always in a position to know that one doesn’t know p or in a position to know that one doesn’t know not-p. Even suitably refined, the principle faces a range of counterexamples in which it misleadingly and persistently seems to one that one knows whether p without it seeming to one that one knows p nor that one knows not-p. These cases also threaten the book’s case for the luminosity of second-order ignorance, which is in turn central to its derivation of strongly internalist principles of justification.