Most content externalists concede that even if externalism is compatible with the thesis that one has authoritative self-knowledge of thought contents, it is incompatible with the stronger claim that one is always able to tell by introspection whether two of one’s thought tokens have the same, or different, content. If one lacks such authoritative discriminative self-knowledge of thought contents, it would seem that brute logical error – non-culpable logical error – is possible. Some philosophers, such as Paul Boghossian, have argued (...) that this would present a big problem for externalism, forcing the externalist to overhaul our norms of rationality. I consider several externalist strategies to block this possibly unhappy epistemological consequence, but I argue that they all fail. (shrink)

The Burge-Putnam thought experiments have generated the thesis that beliefs are not fixed by the constitution of the body. However, many philosophers have thought that if this is true then there must be another content-like property. Even if the contents of our attitudes such as the one in ‘believes that aluminum is a light metal’, do not supervene on our physical makeups, nevertheless people who are physical duplicates must be the same when it comes to evaluating their rationality and explaining (...) their actions. I argue that the considerations motivating this view are best handled with just the ordinary ‘that’-clause contents. (shrink)

Many philosophers have used premises about concepts and rationality to argue that the protagonists in the various Twin Earth thought experiments do not have the concepts that content externalists say they have. This essay argues that this popular internalist argument is flawed in many different ways, and more importantly it cannot be repaired in order to cast doubt on externalism.