People speak of the 'Chomsky revolution', for Noam Chomsky has brought his own highly specialised field of linguistics into the centre of the thought of today. His search for the universal in language is a search for understanding of the human mind, and of the relationship of mind and body. It is this which crowds Chomsky's lectures with students of philosophy, psychology, biology, anthropology, and which require anyone seeking to understand the revolution in modern thought to venture some distance into this rather forbidding field.