Jung's early essay "Psychoanalysis and association experiment" (Psychoanalyse und Assoziationsexperiment) was published in the Journal "Diagnostic Association Studies" in 1904. Here a young Jung, while working at the Bürghölzli psychiatric clinic in Zurich, explores concepts such as the Word Association Test, Identification of Complexes, the Nature of Complexes and Psychotherapeutic implications of these concepts. This edition is a new translation from the original German manuscript with an Afterword by the Translator, a philosophic index of Jung's terminology and a timeline of his life and works. This essay was published in the Scientific Psychology Journal "Diagnostische Assoziationsstudien" (Diagnostic Association Studies) and it represents one of his earlier forays into experimental psychology. The publication, co-authored with Franz Riklin, aimed to investigate and understand the unconscious processes affecting an individual's conscious responses to stimuli. It marked an important phase in Jung's exploration of the unconscious mind. Through word association tests, he identified the presence of emotionally charged complexes that affect conscious thought, laying the groundwork for many of his later theories. Here we see Jung fully under the influence of Frued's 1901 work "The Psychopathology of Everyday Life". In Psychoanalysis and the Association Experiment (Psychoanalyse und Assoziationsexperiment), published in 1904, Carl Jung explores the application of the word association test within psychoanalysis. This early study marked a significant development in Jungs contributions to experimental psychology and laid the groundwork for his later theories on the unconscious and psychological complexes. The word association experiment involved presenting subjects with a series of stimulus words and recording their immediate responses. By analyzing the latency (reaction time) and the emotional intensity of the responses, Jung believed that underlying, emotionally charged complexes could be revealed. These complexes, according to Jung, were clusters of repressed emotions and thoughts buried in the unconscious, often linked to unresolved conflicts from earlier life experiences. In this study, Jung examined the nature of these complexes and their effect on both conscious and unconscious behavior. The experiment demonstrated that certain words triggered longer reaction times or unusual responses, signaling that the subject had an emotional conflict tied to that word. This method allowed for indirect access to the subjects unconscious, a revolutionary approach at the time that differed from Freuds focus on dream analysis or free association. Jungs use of the association test not only deepened the understanding of individual psychological dynamics but also contributed to the early foundations of personality theory.