Abstract

Diverse epistemologists have proposed this Discriminability Postulate : If S knows that p, then S can discriminate between the case that p and other relevant alternatives. I propose that DP derives from other, more basic postulate, that sees knowledge as providing some Warrant Against the Risk of Error : If S knows that p, then this knowledge confers on S’s belief that p a warrant against the risk of error. The kind of error mentioned in WARE is the error consisting in mistaking the case that p for some of its relevant alternatives. But the possibility of mistaking in that sense entails that the subject has appropriate representational access to the two items that have to be distinguished. The fact that DP derives from WARE provides grounds to think that if DP is true, then the discriminative capacities than it involves are not jeopardized when the subject cannot have representational access to one of the corresponding items. A corollary of this idea is a weakening of DP and a subsequent reduction of its potential to raise sceptical doubts against claims of knowledge.