The Nuer: A description of the modes of livelihood and political institutions of a Nilotic people
By E.E. Evans-Pritchard
The link above goes to Archive.org, where you can download this book in PDF, Kindle, text, and other formats. It's OCR'd from the 1940 book, and you'll find some scan errors, but the book is generally intact and generally quite interesting. The first in a trilogy on the Nuer, an African people living in the Sudan and Ethiopia, this book is also a classic of structural-functionalism.
Unfortunately, I'm not an anthropologist and can't provide a good discussion of structural-functionalism or evaluate Evans-Pritchard's work in those terms. But I can recommend The Nuer as an intriguing and at times amusing book. Evans-Pritchard's self-deprecating discussion of methodology, for instance, reads like the trials of Job: "an adequate sociological study of the Nuer was impossible in the circumstances in which most of my work was done," he allows, professing to be amazed that the book has appeared at all.
When he visited Tribe A, they stole the game he shot to feed himself and only spoke to him to demand tobacco. Moving to Tribe B, he began to gain their confidence, only to be stymied by a Government raid. At this point he had only done three and a half months' work among the Nuer.
Later, he visited Tribe C, discovering that "Nuer are expert at sabotaging inquiry": they would visit his tent, demand tobacco, and give him the runaround when he asked questions. He dubbed the resulting condition "Nuerosis." Giving up, he moved to Tribe D, began making progress - then had to be evacuated due to malaria.
On a third trip, he had planned to study another people, but "as delay was caused by diplomatic chicanery I spent two and a half months" near the Nuer; an imminent invasion compelled him to give up on these studies and join the Nuer for another seven weeks. "My total residence among the Nuer was thus about a year," he tells us, admitting that this timespan was inadequate.
Inadequate or not, Evans-Pritchard manages to paint an intriguing portrait of the Nuer, herdsmen who love cattle more than themselves, subsist primarily on milk, millet and meat, and "strut about like lords of the Earth, which, indeed, they consider themselves to be." They "tend to define all social processes and relationships in terms of cattle. Their social idiom is a bovine idiom," he argues. This fact impacts their social structure: "since milk is considered essential, the economic unit must be larger than the simple family group." They consider it repulsive to eat most reptiles, all birds, and all eggs. (We in turn would most likely not want to sample their cheese.) Their devotion to cattle also impacts their estimation of value: a man without cattle is not considered a man, something that probably affected Evans-Pritchard's earlier inquiries since he acquired his own cattle only later.
As "lords of the earth," the Nuer do not serve each other or order each other around; their societal structure is generally decentralized and based on lineage. ("By structure we mean relations between groups of persons within a system of groups.") The tribe is segmentary, based on "complementary tendencies toward fission and fusion."
Overall, the book is fascinating. Without a stronger background in structural-functionalism, I'm certain I missed many implications of this work. But as a standalone work, it is insightful and well worth reading.