The opacity of knowledge: An externalist's case for widespread KK-failure

Abstract

An epistemic externalist should allow that whatever proposition about the world, P, one knows to be true, there will be some other fact one is not in a position to know, but which is required for the belief in P to count as knowledge. We contend that ordinary knowers are cognizant of such ‘unknown knowledge-makers’. On this basis, we present a
novel case—we distinguish it from rivals—for widespread KK-failure: quite generally, if one knows P, one will not be in a position to know that one knows it.