This book provides an in-depth discussion of embodied intelligence, an emerging field in artificial intelligence, which is the integration of intelligent systems with physical bodies. The book systematically discusses the theoretical framework of embodied intelligence, including the interaction between body and mind, the unity of perception and behavior, and how agents learn to write adaptations through interaction with the environment. The book details the free energy principle, a key theory for understanding the organizing principle of living organisms and intelligent systems, and explores the application of this principle to the design of artificial intelligence, such as reinforcement learning of the unity of perception and action. In addition, the book discusses the interpretation of intelligence from a multidisciplinary perspective, as well as strategies for integrating spatial and embodied intelligence, providing readers with a comprehensive window into the future trends of AI.