Morell's goal is to write about animal minds for a general audience, and she does so by visiting and discussing the topic with groups of scientists who are exploring the cognitive abilities of different species. The result is a rich and fascinating, though somewhat subjective, assessment of how the cognition of widely varied animals works. Readers learn about Jane Goodall and her chimpanzees, Diana Reiss and her work with dolphins, and Irene Pepperberg and her special training of her talking parrot, Alex. Yet science author/journalist Morell (Ancestral Passions, 1995) also visits researchers working with lesser-known, "thinking" animals, including archerfish that spit out jets of water at her, individually marked ants that teach, and elephants that examine bones of their dead. She contrasts the abilities of human-centered dogs with those of more alert but shyer wolves. In conversation, the scientists explain what the different species are doing and how they find out what the animals think. The author starts off by discussing philosophers' attitudes to animals over the centuries and then, having shown readers the rich tapestry of their minds, concludes that "we live in a world of sentient beings" and thus must rethink our attitudes to and treatment of them. Summing Up: Highly recommended. All levels/libraries. J. A. Mather University of Lethbridge