Fallibilism, Epistemic Possibility, and Concessive Knowledge Attributions

1. If knowing requires believing on the basis of evidence that entails what’s believed, we have hardly any knowledge at all. Hence the near-universal acceptance of fallibilism in epistemology: if it’s true that “we are all fallibilists now” (Siegel 1997: 164), that’s because denying that one can know on the basis of non-entailing evidence is, it seems, not an option if we’re to preserve the very strong appearance that we do know many things (Cohen 1988: 91). Hence the significance of concessive knowledge attributions (CKAs) (Rysiew 2001) – i.e., sentences of the form ‘S knows that p, but it’s possible that q’ (where q entails not-p). To many, utterances of such sentences sound very odd indeed. According to David Lewis (1996: 550), however, such sentences are merely “overt, explicit” statements of fallibilism; if so, their seeming incoherence suggests that, contrary to our everyday epistemic pretensions, “knowledge must be by definition infallible” after all (ibid.: 549). Recently Jason Stanley (2005) has defended fallibilism against the Lewisian worry that overtly fallibilistic speech is incoherent. According to Stanley, CKAs are not just odd-sounding: in most cases, they are simply false. But this doesn’t impugn fallibilism. Insofar as the oddsounding utterances Lewis cites state the fallibilist idea, the latter portion thereof (‘S cannot eliminate a certain possibility in which not-p’, e.g.) expresses the idea that the subject’s evidence doesn’t entail what’s (allegedly) known (hence, the negation of any contrary propositions).