"Fifty years ago, Joseph Greenberg put forward the now widely-accepted classification of African languages. This book charts the progress of his work on language classification in Oceania, the Americas, and Eurasia, in which he proposed the language families Indo-Pacific, Amerind, and Eurasiatic. It shows how he established and deployed three fundamental principles: that the most reliable evidence for genetic classification is the pairing of sound and meaning; that nonlinguistic evidence, such as skin colour or cultural traits, should be excluded from the analysis; and that the vocabulary and inflections of a very large number of languages should be simultaneously compared. The volume includes Joseph Greenberg's substantive contributions to the debate his work provoked and concludes with his writings on the links between genetic linguistics and human history."--BOOK JACKET.