 In addition, there is a burgeoning literature on whether EXT is compatible with epistemic internalism, a view where knowledge or justification supervenes on what’s in the head (Pritchard &amp; Kallestrup 2004, Brown 2007, Gerken 2008; also cf. Chase 2001, Brueckner 2002. Goldberg 2007a is germane too). Many of the issues here turn on what kind of self-knowledge is allowed by EXT, and in particular, whether such knowledge is discriminating enough for justificatory purposes.