Saul Kripke, in a series of classic writings of the 1960s and 1970s, changed the face of metaphysics and philosophy of language. Christopher Hughes offers a careful exposition and critical analysis of Kripke's central ideas about names, necessity, and identity, and in the process makes significant contributions to continuing debates about such topics as modality, essence, natural kinds, and the relation between the mental and the physical. No specialist knowledge in either the philosophy of language or metaphysics is presupposed; Hughes's book will be valuable for anyone working on the ideas which Kripke made famous in the philosophy world.