1. IntroductionIn this superb book, Williams sets a very ambitious goal for himself: to sketch biconditionals that define representational conditions in non-representational terms (p. xvii). Representation is not a spooky, primitive capacity of the mind; it is built from more basic ingredients. At the centre is his radical interpretation theory of belief and desire, inspired by the work of David Lewis. To a first approximation: Basic radical interpretation theory. The correct assignment of beliefs and desires to an agent is the most rationalizing assignment given her perceptual evidence and dispositions to act. (pp. 16, 97ff)Williams does not give a master argument for this account of belief and desire over rival accounts in which constitut...