This is the very first authoritative book on the role of Carl Gustav Carus (1789-1869) in the history of psychology. Carus was the initiator of the notions of development, unconscious, and archetype in psychology. The book emphasizes the interdisciplinary focus of Carus' work as it was based on the literature and art of his time and is closely related with medicine and Naturphilosophie. The readership of the book will get access to the life course of a key figure of science of the 19th century.