In 1838 Charles Darwin jotted in a notebook, “He who understands baboon would do more towards metaphysics than Locke.” Baboon Metaphysics is Dorothy L. Cheney and Robert M. Seyfarth’s fascinating response to Darwin’s challenge.           Cheney and Seyfarth set up camp in Botswana’s Okavango Delta, where they could intimately observe baboons and their social world. Baboons live in groups of up to 150, including a handful of males and eight or nine matrilineal families of females. Such numbers force baboons to form a complicated mix of short-term bonds for mating and longer-term friendships based on careful calculations of status and individual need.           But Baboon Metaphysics is concerned with much more than just baboons’ social organization—Cheney and Seyfarth aim to fully comprehend the intelligence that underlies it. Using innovative field experiments, the authors learn that for baboons, just as for humans, family and friends hold the key to mitigating the ill effects of grief, stress, and anxiety.           Written with a scientist’s precision and a nature-lover’s eye, Baboon Metaphysics gives us an unprecedented and compelling glimpse into the mind of another species. “The vivid narrative is like a bush detective story.”—Steven Poole, Guardian “Baboon Metaphysics is a distillation of a big chunk of academic lives. . . . It is exactly what such a book should be—full of imaginative experiments, meticulous scholarship, limpid literary style, and above all, truly important questions.”—Alison Jolly, Science “Cheney and Seyfarth found that for a baboon to get on in life involves a