The Languages of Africa is a 1963 book of essays by the linguist Joseph Greenberg, in which the author sets forth a genetic classification of African languages that, with some changes, continues to be the most commonly used one today. It is an expanded and extensively revised version of his 1955 work Studies in African Linguistic Classification, which was itself a compilation of eight articles which Greenberg had published in the Southwestern Journal of Anthropology between 1949 and 1954. It was first published in 1963 as Part II of the International Journal of American Linguistics, Vol. 29, No. 1; however, its second edition of 1966, in which it was published (by Indiana University, Bloomington: Mouton & Co., The Hague) as an independent work, is more commonly cited. Its author describes it as based on three fundamentals of method: "The sole relevance in comparison of resemblances involving both sound and meaning in specific forms." "Mass comparison as against isolated comparisons between pairs of languages." "Only linguistic evidence is relevant in drawing conclusions about classification." Innovations Greenberg's Niger–Congo family was substantially foreshadowed by Westermann's "Western Sudanic", but he changed the subclassification, including Fulani (as West Atlantic) and the newly postulated Adamawa–Eastern, excluding Songhai, and classifying Bantu as merely a subfamily of Benue–Congo (previously termed "Semi-Bantu"). Semitic, Berber, Egyptian and Cushitic had been generally accepted as members of a "Hamito-Semitic" family, while Chadic, Fulani, "Nilo-Hamitic" and Hottentot had all been controversially proposed as members. He accepted Chadic (while changing its membership), and rejected the other three, establishing to most linguists' satisfaction that they had been classified as "Hamitic" for purely typological reasons. This demonstration also led to the rejection (by him and by linguistics as a whole) of the term Hamitic as having no coherent meaning in historical linguistics; as a result, he renamed the newly reclassified family "Afroasiatic". Following Schapera and rejecting Meinhof, he classified Hottentot as a member of the Central Khoisan languages. To Khoisan he also added the much more northerly Hadza (Hatsa) and Sandawe. His most revolutionary step was the postulation of the Nilo-Saharan family. This is still controversial, because so far attempts to reconstruct this family have been unsuccessful, but it holds promise and is it widely used. Prior linguists had noticed an apparent relationship between the majority of the languages, but had never formally proposed a family. These languages – the Eastern Sudanic, Central Sudanic, Kunama and