Over his long career, Jung maintained a compelling interest in occult phenomena as a subject of psychological concern. His first publication, his M. D. dissertation in 1902, was a psychiatric study of a medium, and he "dabbled in spookery" (as he wrote Freud) in his undergraduate days and before. His letters and autobiography frequently comment on para-psychological phenomenon. The present collection brings together Jung's writings on the occult in the Collected Works, beginning with the 1902 monograph and coming up to 1960, the year before his death.