In offering this volume to the public, there is no desire to promulgate any ism or cult, but to present the records and deductions of thirty years experimental research in the science of normal and abnormal psychology, as the same pertains to the obscure problems of a life hereafter and its relation to human affairs, which all thinking minds must recognize as being of utmost importance. – From the Introduction

Carl August Wickland (1861–1945) was a 20th-century Swedish-American psychiatrist and psychical researcher. Wickland turned away from conventional medical psychology and toward the belief that psychiatric illnesses were the result of influence by spirits of the dead. Wickland came to believe that a large number of his patients had become possessed by what he called "obsessing spirits", and that low-voltage electric shocks could dislodge them, while his wife Anna acted as a medium to guide them to "progress in the spirit world".