I argue that there is a tension between two of the most distinctive theses Sven Rosenkranz’s Justification as Ignorance: (i) central thesis concerning justification, according to which an agent has propositional justification believe p iff they are in no position know and (ii) desire avoid logical omniscience by imposing only “realistic” idealizations on epistemic agents.

Logical omniscience states that the knowledge set of ordinary rational agents is closed for its logical consequences. Although epistemic logicians in general judge this principle unrealistic, there no consensus on how it should be restrained. The challenge conceptual: we must find adequate criteria separating obvious consequences (consequences which closure certainly holds) from non-obvious one...