Part A. External realism -- The picture of external realism -- The model-theoretic arguments -- Attempts to constrain reference -- The just-more-theory manœvre -- Empiricism and empirical content -- Sceptical veils of various fabrics -- From Cartesian to Kantian angst -- Part B. The tenacity of Cartesian Angst -- How the serpent entered Eden -- Nonrealism -- Natural realism -- Justificationism -- Part C. Dissecting brains in vats -- Putnam's brain-in-vat argument -- The resilence of the brain-in-vat argument -- Davidson's cogito -- Vat variations -- Mitigated aporia -- Part D. Realism within limits -- Semantic externalism -- Conceptual relativism -- Conceptual cosmopolitanism.