This book investigates the origins and development of the theory of four stages of liberation in Pāli literature. This theory is an important soteriological cartography in early Buddhism, particularly Theravāda Buddhism. Amrita Nanda challenges the traditional interpretation of the four stages by recognizing the impact of the changing socio-religious factors on the theory’s origins and subsequent development. Based primarily on the Pali literary sources, this study utilizes sometimes-overlooked aspects of these texts. This book first traces the origins of each stage individually; then, it traces the formation of the theory and its subsequent development.