This book is one of the classics of ethnography - indeed, one of the works which defines what ethnography and anthropology are.
The Nuer is an account of a group of pastoralists living in the Sudan as Evans-Pritchard knew them when he did field work in er... uh... the late 30s early 40s. The first half of the book is a detailed and lively (for an academic) account of their way of life, the seasonal rhythms of the year, and their intense interest in cattle.
The second half of the book than deals with the main subject of the book: the social organization of the Nuer. E-P moves to a greater and greater level of abstraction, creating a more and more crystalline view of the patterns of kinship and marriage that underlie Nuer life. The main structure is the lineage system - a group of people all related from a common ancestor through an unbroken line of male succession.
This book is famous because of E-P's account of the lineage system. The concept of the lineage and descent became key in anthropology, and E-P's Nuer materials helped provide the perfect example of the lineage as theorized by Radcliffe-Brown, E-P's teacher.
As a result of this book, anthropologists spend the next two decades running around all over the world looking for lineage systems. As it turns out, this sort of system is not particularly widespread across the world - at least not in its pure form. Indeed, it turns out that E-P's formulation was too neat and clean and too crystalline. As one pundit put it, "not even the Nuer are like The Nuer". So one drawback of the book is the false clarity that it provided. This was useful in the forties and fifties, but meant that eventually the study of kinship and social organization would have to move out of the paradigm E-P had set up.
Another problem with the book is the fact that it takes place in a vacuum. It is easy not to notice that the Nuer are under the sway of British authority and had recently been bombed when E-P arrived. The colonial context of the book is supressed.
There are other critcisms that could be made of the book - it is now a half-century behing the times - but it stands up today as a good read and a fascinating argument. The fact that reactions to it have been so extreme - overwhelming enthusiasm, abiding hatred, quizzical puzzlement, cow obsession - point to the fact that a book doesn't have to be loved forever to be read forever. Like all classics, The Nuer both good to read and good to think.