In my dissertation I investigate the possibility of thought about a mind-independent reality. I consider this in light of the requirement that Frege and Dummett place on an adequate theory of thought. I argue that the manifestation requirement that Dummett places on a theory of meaning has not been adequately responded to unless one can simultaneously live up to his requirement for a justification of our preferred deductive practices. I argue why common responses fail to accomplish this, but end by suggesting that one can experientially justify deduction and thereby support a realist theory of meaning