This book is Shi Lei's compilation and interpretation of the relevant thoughts of Hegel, the master of German classical philosophy. Focusing on the core concepts of Hegel's philosophical system - "spirit" and "absolute knowledge" - it aims to sort out its obscure and difficult-to-understand dialectical development process. The compiler strives to present Hegel's development of consciousness, self-awareness, reason and absolute spirit in clear and accurate language, providing readers with a key to enter Hegel's world of speculative philosophy.