We have considered three arguments in chapter eight purporting to show that the thesis of content externalism, ETC, rules out first-person authority in the case of many beliefs. Davidson and Burge have adequately replied to the third: the argument from counterfeit error. However, what they have to say about first-person authority does not provide the basis for a reply to either Boghossian's argument or the McKinsey* argument. Moreover, Davidson and Burge's accounts of first-person authority are inadequate. In the next chapter I will examine an ingenious account of first-person authority defended by Crispin Wright. In this one I will consider how Boghossian's argument and the McKinsey* argument can best be met.

BOGHOSSIAN'S ARGUMENT

Boghossian's argument goes like this. Someone is shunted back and forth between Earth and Twin Earth. On Earth she uses ‘Water is tasteless’ to express one belief. On Twin Earth she uses the same sentence to express a different belief. Subsequently, she is told that the shunting between Earth and Twin Earth has taken place. She is not told whether she was on Earth or Twin Earth during the previous day. Call this situation the switching situation.

Boghossian contends that an individual in the switching situation lacks what he calls introspective knowledge about what she believes. Clearly, if his argument succeeds, it shows that someone in the switching situation does not know a priori that she believes that water is tasteless. Two questions need to be addressed.