Noam Chomsky is one of the leading intellectual figures of modern times. He has had a major influence on linguistics, psychology and philosophy, and a significant effect on many other disciplines, from anthropology to mathematics, education to literary criticism. In this rigorous yet accessible account of Chomsky's work and influence, Neil Smith analyses Chomsky's key contributions to the study of language and the study of mind. He gives a detailed exposition of Chomsky's linguistic theorizing, discusses the psychological and philosophical implications of Chomsky's work, and argues that he has fundamentally changed the way we think of ourselves, gaining a position in the history of ideas on a par with that of Darwin or Descartes.