BonJour argues that the premises of an argument attacking genuine a priori knowledge must, at pain of self-defeat, be a posteriori in character.
It is the entailment relation between them--P entails N--that is claimed, apparently, a priori. The question is whether NC would succeed if this entailment was reduced to an analytic truth or eliminated altogether.
Part 3 examines the relation between the subjective and the objective a priori
. Chapter 10 argues for the equality of man and world.
how a priori
knowledge of matters of fact is possible.' The problem with this attempt to play devil's advocate is that the line of argument offered to the objector, which includes endorsing non-factualism about modality, can not support the form of skepticism about a priori
knowledge that Cassam means to entertain.