Full Idea
If coherentism is construed as involving the believer's entire body of beliefs, that would imply, most implausibly, that the justification of a belief in one area (physics) could be undermined by serious incoherence in another area (art history).
Gist of Idea
My incoherent beliefs about art should not undermine my very coherent beliefs about physics
Source
Laurence Bonjour (A Version of Internalist Foundationalism [2003], 3.1)
Book Reference
Bonjour,L/Sosa,E: 'Epistemic Justification' [Blackwells 2003], p.45
A Reaction
Bonjour suggests that a moderated coherentism is needed to avoid this rather serious problem. It is hard to see how a precise specification could be given of 'areas' and 'local coherence'. An idiot about art would inspire little confidence on physics.