This is a survey of the history of Taoism from approximately the third century BC to the fourteenth century AD. For many years, it was customary to divide Taoism into philosophical Taoism and religious Taoism. The author has long argued that this is a false division and that religious Taoism is simply the practice of philosophical Taoism. She sees Taoism as foremost a religion, and the present work traces the development of Taoism up to the point it reached its mature form (which remains intact today, albeit with modern innovations). The main aim of this history of Taoism is to trace the major lines of its doctrinal evolution, wide varieties of factors that came into play over a long period of disconnected eras, the constant absorptions of outside contributions, and the progress that integrates them. The author shows how certain recurrent themes are treated in different ways in different eras and different sects. Among these themes are the Ultimate Truth, immortality, the Sage, the genesis and the end of the world, retribution for good and evil acts, representations of heavens and hells, and the connections between life and the spirit, between life and death, between man and society, and between mystical experience and the social form of religion.