In Hauser's mind, the question of whether animals think and feel is moot. They do, he assures his readers. He concerns himself with discerning the subtlety of animal emotions and how and what animals think. A psychologist recognized for his expertise in this arena, Hauser makes his points by describing his own research and other scientists' advances in the areas of neuroscience, evolutionary theory, and human-infant cognition. Rolling these elements together, he asserts that all animals are equipped with mental tools for solving ecological and social problems.
Some universal tools allow for the basic capacity to recognize objects, count, and navigate.
Other highly specialized tools evolved to meet unique ecological and social needs. The biggest difference between people and animals, he asserts, comes in the form of self-awareness. Only our closest primate kin bear the ability to recognize themselves in mirrors. Without a sense of self-awareness, Hauser believes, animals must lack a moral sense. Originally published in hardcover in 2000.