This book examines the ideas and influences of a nearly forgotten Swedish-American philosopher, John Elof Boodin (1869–1950). A friend and student of William James and protégé of Josiah Royce at Harvard, Boodin combined Jamesian pragmatism and Roycean idealism in developing original scholarship (nearly sixty articles and eight books) from 1900 to 1947, in addition to a volume of posthumous papers published in 1957. Although he is seldom remembered today, the enduring importance of pragmatism and the rising influence of process theology today suggests that his close reading of early to mid-twentieth-century science and vast grasp of philosophical issues warrants a renewed interest in his work that can be a valuable antidote to the sterile and constricting effects of reductionism and dogmatic materialism prevalent today in both those fields.