Originally published in the UK in 1970. The central argument of this book is that the structuralist theory and method developed by British and American anthropologists in the study of kinship and social organization are the direct descendants of the researches of Lewis Henry Morgan. Re-examining Morgan's work, the book demonstrates how a tradition of mis-interpretation has disguised the true import of Morgan's discoveries and ideas for Rivers and Radcliffe-Brown and the generation of anthropologists inspired by them.