[Letters from Paul Julius Möbius to Auguste-Henri Forel : "…that the harmony of perceptions on this novel point is also repeated on completely different issues"].

This article provides an analysis of the content of 15 letters and postcards written by the Leipzig neurologist Paul Julius Möbius to his Zurich-based colleague Auguste-Henri Forel between 1889 and 1902. Moreover, they are set in the context of the works of the two correspondence partners. The 15 documents preserved at the University of Zurich Medico-Historical Institute and Museum comprise one half of the correspondence, whereas the letters Forel sent in response do not seem to have been preserved. So far, biographic research has neglected the letters analyzed here. Hypnotism and medical suggestion as well as their effects and efficiency in treating and maybe healing certain nervous and mental disorders, primarily psychoneuroses but also certain somatic disorders, formed the bond that connected Möbius and Forel. The exchange was less concerned with discussing details or concepts of hypnosis. Möbius seemed to be more interested in studying the practical application with Forel. Moreover, Möbius and Forel shared the view that contemporary, largely brain-biologically oriented conventional psychiatry had largely neglected or at least underestimated the psychological component of both nervous and mental disorders. Both shared the notion that electrotherapy, widely used at the time, had a strong suggestive component. The letters revealed that both correspondents requested reviews or discussion of their own papers from each other. Forel invited Möbius to consider writing for his Zeitschrift für Hypnotismus (Journal for Hypnotism). The correspondence also revealed that their harmony in certain views did not prevent them from refusing requests made by the other. The letters discussed in this article enrich the knowledge on these two prominent neurologists of the late nineteenth and early twentieth centuries.