Full Idea
The Master Argument for coherentism is the claim that a justifier requires asserted propositional content, and that only beliefs represent propositions assertively.
Gist of Idea
Coherentism rests on the claim that justifications must be beliefs, with propositional content
Source
James Pryor (There is immediate Justification [2005], §4)
Book Reference
'Contemporary Debates in Epistemology', ed/tr. Steup,M/Sosa,E [Blackwell 2005], p.188
A Reaction
I think this claim (which Pryor attacks) is correct. A key point is that almost any experience can be delusional, and in need of critical evaluation. We would even only accept an experience as being necessarily veridical after critical evaluation.