Brueckner and Ebbs debate whether a person can coherently doubt that she knows what thoughts her utterances express.This book is intended for advanced undergraduate philosophy majors; graduate students in philosophy; experts in philosophy of language, philosophy of mind and epistemology; and cognitive psychologists and linguists who are interested in semantics and epistemology.This book is intended for advanced undergraduate philosophy majors; graduate students in philosophy; experts in philosophy of language, philosophy of mind and epistemology; and cognitive psychologists and linguists who are interested in semantics and epistemology.Language users ordinarily suppose that they know what thoughts their own utterances express. We can call this supposed knowledge minimal self-knowledge. But what does it come to? And do we actually have it? Anti-individualism implies that the thoughts which a person's utterances express are partly determined by facts about their social and physical environments. If anti-individualism is true, then there are some apparently coherent sceptical hypotheses that conflict with our supposition that we have minimal self-knowledge. In this book, Anthony Brueckner and Gary Ebbs debate how to characterize this problem and develop opposing views of what it shows. Their discussion is the only sustained, in-depth debate about anti-individualism, scepticism and knowledge of one's own thoughts, and will interest both scholars and graduate students in philosophy of language, philosophy of mind and epistemology.Introduction; 1. Brains in a vat Anthony Brueckner; 2. Scepticism, objectivity, and brains in vats Gary Ebbs; 3. Ebbs on scepticism, objectivity, and brains in vats Anthony Brueckner; 4. The dialectical context of Putnam's argument that we are not brains in vats Gary Ebbs; 5. Trying to get outside your own skin Anthony Brueckner; 6. Can we take our words at face value? Gary Ebbs; 7. Is scepticism about self-knowledge incoherent? Anthony Bruecknelc,