Verena Kast´sbook, initially published in German in 1980 by Bonz Verlag and now available in English, continues this series’ mission of making classic works in analytical psychology accessible to a wider audience. This concise book, once available exclusively to students of the C.G. Jung Institute in Zurich, is now accessible to a broader readership. This book emphasize that the importance of C.G. Jung’s Association Experiment in therapeutic practice lies in its dual function: on one hand, it serves as a diagnostic tool, and on the other, it has a profoundly therapeutic effect. The association experiment, developed by C.G. Jung in the early 20th century, was a groundbreaking method for exploring the unconscious. Jung used this experiment to study how individuals respond to a series of stimulus words, measuring reaction times and observing emotional or physiological reactions. The aim was to identify “complexes” — emotionally charged groups of ideas that influence thoughts, feelings, and behaviors, often outside of conscious awareness. Jung’s method involved presenting a word and asking participants to respond with the first word that came to mind. Delays, repetitions, or unusual responses often indicated the presence of a psychological complex.