Commentary on Wolf and Cohen: Reasoning about Public Evidence

Barker and Taranto (2003) and Taranto (2006) give an account of clarity based on shared belief. On the shared-belief account, It is clear that p will be true just in case both the speaker and the listener mutually believe that p. In Barker (2009), I argue that belief is neither necessary nor sufficient to guarantee clarity. After all, if the evidence is weak, It is clear that God exists is false no matter how strongly or how mutually we believe in God. Likewise, admitting that something is painfully clear does not guarantee that the discourse participants believe it, at least, not as a matter of entailment. Barker (2009) proposes instead a modal account based on justification: a proposition p is clear just in case all sufficiently normal worlds consistent with the common ground (i.e. consistent with publicly available evidence) are p-worlds. Then It is clear that p is true just in case the publicly available evidence justifies concluding that p.