Knowledge, intuition and implicature

Moderate pragmatic invariantism (MPI) is a proposal to explain why our intuitions about the truth-value of knowledge claims vary with stakes and salient error-possibilities. The basic idea is that this variation is due to a variation not in the propositions expressed (as epistemic contextualists would have it) but in the propositions conversationally implicated. I will argue that MPI is mistaken: I will distinguish two kinds of implicature, namely, additive and substitutional implicatures. I will then argue, first, that the proponent of MPI cannot appeal to additive implicatures because they don’t affect truth-value intuitions in the required way. Second, I will argue that the proponent of MPI cannot appeal to substitutional implicatures either because, even though they may have the required effects on truth-value intuitions, they don’t feature in the relevant cases. It follows that MPI is mistaken because whether the proponent of MPI appeals to additive or substitutional implicatures, at least one of the claims that make up her view is false. Along the way, I will suggest principles about implicatures that should be relevant not only to MPI, but to pragmatic accounts of seemingly semantic intuitions in general.