This chapter reviews the scholarly responses to The Principles of Psychology, from immediately after its publication to the present time. Concerns about its impressionistic approach, loose logic, relatively unsystematic and oddly organized character, literary quality, and seemingly materialistic bias are highlighted, with comments made about each accusation. The chapter then proceeds to comment on the abbreviated version of this masterpiece, Psychology: Briefer Course, and the popularity and historical impact of both Principles and Briefer Course over the following years. It also reviews subsequent developments of James’s thought, especially relative to clinically oriented psychology and the psychology of religion, over the last decades of his life. It closes with observations about the appropriate way of reading his classic text and about its continuing relevance to both psychology and philosophy. Finally, references to the wider cultural influence of James are provided, along with a partial listing of significant individuals impressed or influenced by James and Principles.