Noam Chomsky continues to be one of the most influential intellectual figures of modern times. His wide-ranging contributions to the fields of linguistics, psychology, philosophy and politics have revolutionised our view of language, the mind and human nature. Assuming no prior knowledge of linguistics, this book explores Chomsky's key theories, especially recent developments in his Minimalist Program, addressing issues such as: how do we know a language? How do children acquire this knowledge? How did language evolve? This third edition has been expanded and thoroughly updated and includes an exploration of Chomsky's contributions to philosophy and psychology, outlining the impact of his radical and often controversial views. It concludes with an account of his political activism and his critique of recent developments such as the Arab Spring, Wikileaks and the Occupy movement. There is also a new section covering his views on climate change and nuclear disarmament.