Full Idea
Inferentialism faces the grave problem of separating patterns of inference that are to count as essential to the meaning of an expression from those that will count as accidental (a form of the analytic/synthetic distinction).
Gist of Idea
How does inferentialism distinguish the patterns of inference that are essential to meaning?
Source
Timothy Williamson (Knowledge First (and reply) [2014], p.6)
Book Reference
'Contemporary Debates in Epistemology (2nd ed)', ed/tr. Steup/Turri/Sosa [Wiley Blackwell 2014], p.6
A Reaction
This sounds like a rather persuasive objection to inferentialism, though I don't personally take that as a huge objection to all internalist semantics.
Related Ideas
Idea 19533 Inferentialist semantics relies on internal inference relations, not on external references [Williamson]
Idea 19535 Internalist inferentialism has trouble explaining how meaning and reference relate [Williamson]