Knowledge and implicatures

In recent work on the semantics of 'knowledge'-attributions, a variety of accounts have been proposed that aim to explain the data about speaker intuitions in familiar cases such as DeRose's Bank Case or Cohen's Airport Case by means of pragmatic mechanisms, notably Gricean implicatures. This paper argues that pragmatic explanations of the data regarding 'knowledge'-attributions are unsuccessful and concludes that in explaining those data we have to resort to accounts that (a) take those data at their semantic face value (Epistemic Contextualism, Subject-Sensitive Invariantism or Epistemic Relativism), or (b) reject them on psychological grounds (Moderate Insensitive Invariantism). To establish this conclusion, the paper relies solely upon widely accepted assumptions about pragmatic theory, broadly construed, and on the Stalnakerian insight that linguistic communication takes place against the backdrop of a set of mutually accepted propositions: a conversation's common ground.