This book examines the force that compels us to believe our senses, thoughts, impulses, and feelings, which begins with naïve realism and extends to belief in abstractions. Santayana called it animal faith. While unproblematic for most creatures, the natural state of embodiment may seem awkward and arbitrary to a self-conscious mind that can imagine limitless possibilities, including freedom from suffering and mortality. Our science aims to free us not only from gravitation and chemistry, but even from death. We are the only creature on this planet with a notion to secure, through technology, a future for our species. In view of artificial general intelligence, we can imagine a post-human successor. Yet, both individual and species depend on the commitment to cognition characteristic of biology. Could a post-biological being enjoy more control over its own internal processes and behavior, resulting in more internal freedom and a better society? What are the limits for possible mind? Should humanity pursue a technological path to transcendence, or should it accept its place in nature, as Indigenous cultures seem to do? The book explores these sweeping questions, which relate to more immediate issues such as the future of capitalism and AI, as well as to perennial questions such as the nature and role of consciousness