"On the Borders of Science" is a study of psychical research and parapsychology in Germany during the Imperial and inter-war periods. Part of the occult revival that occurred in Europe and America towards the end of the nineteenth century, the scientific study of mediumism appealed to those members of Germany's educated middle-classes who were dissatisfied with the one-sided materialistic Weltanschauung that, they maintained, dominated contemporary scientific thought to the detriment of both material and moral progress. Concerned, in particular, with the manner in which academic psychology ignored the unconscious in favour of those psychological phenomena that could be quantified using methods borrowed from physiology, these researchers attempted to create a new science, known initially as psychical research, but from the mid 1920s onwards increasingly as parapsychology. The basis for this new discipline, which was intended to promote a more complete world-view, was experimentation with mediums, individuals believed to possess the ability to communicate with the spirits or to access other states of being. Using the clairvoyant predictions, trance speech and ectoplasm produced by mediums to belie the truth of scientific materialism, psychical research and parapsychology posed a challenge both to emerging sciences, such as psychology, and established ones, like physics and biology.
Building on recent studies in this field, which have viewed modem occultism as an engagement with rather than a rejection of modernity, this thesis argues that psychical research and parapsychology offered innovative, if ultimately flawed, solutions to the problems posed by scientific materialism. Using a wide range of primary and archival sources, many of which have not been used before in a study of this type, including the correspondence of Hans Driesch (1867-1941), Albert Hellwig (1880-1950), T. K. Oesterreich (1880-1949) and Albert von Schrenck-Notzing (1862- 1929), it focuses on the relationship between the scientific study of mediumism and science in the German context. The thesis is divided into three parts. The first section is concerned with the emergence of psychical research and its opponent critical occultism during the late nineteenth century. It attempts to recreate the social, cultural and professional milieu in which these disciplines were born. The second section considers experimental and theoretical approaches to the phenomena of mediumism. It aims not only to describe the atmosphere of the laboratory and the dynamics between parapsychologists and mediums, but also to gauge the response of the authorities, including the churches, medical community and the National Socialists, to this nascent science. The final section deals with the conflicts that took place between parapsychologists and their critics during the inter-war period in the hope of ascertaining what was ultimately at stake in the scientific study of mediumism. It concludes by maintaining that these disciplines, what in German are referred to as the border areas of science (Grenzgebiete der Wissenschaft), were anything but peripheral to modernity in the German context. In their attempt to re-imagine science in a more complete form these border sciences were a direct engagement with issues central not only to the scientific endeavor, but to modern life.